James McKinney v. Charles Ryan , 813 F.3d 798 ( 2015 )


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  •                 FOR PUBLICATION
    UNITED STATES COURT OF APPEALS
    FOR THE NINTH CIRCUIT
    JAMES ERIN MCKINNEY,                   No. 09-99018
    Petitioner-Appellant,
    D.C. No.
    v.                   2:03-cv-00774-DGC
    CHARLES L. RYAN,
    Respondent-Appellee.           OPINION
    Appeal from the United States District Court
    for the District of Arizona
    David G. Campbell, District Judge, Presiding
    Argued and Submitted En Banc
    December 15, 2014—Pasadena, California
    Filed December 29, 2015
    Before: Sidney R. Thomas, Chief Judge, and Alex
    Kozinski, Kim McLane Wardlaw, William A. Fletcher,
    Ronald M. Gould, Marsha S. Berzon, Richard C. Tallman,
    Consuelo M. Callahan, Carlos T. Bea, Morgan Christen
    and Jacqueline H. Nguyen, Circuit Judges.
    Opinion by Judge W. Fletcher;
    Dissent by Judge Bea
    2                      MCKINNEY V. RYAN
    SUMMARY*
    Habeas Corpus
    The en banc court reversed the district court’s judgment
    denying Arizona state prisoner James McKinney’s petition
    for a writ of habeas corpus, remanded with instructions to
    grant the writ with respect to McKinney’s death sentence
    unless the state, within a reasonable time, corrects the
    constitutional error in his death sentence or vacates the
    sentence and imposes a lesser sentence consistent with law.
    The en banc court overruled Schad v. Ryan, 
    671 F.3d 708
    (9th Cir. 2011) (per curiam), which prohibited an assumption
    of unconstitutionality under Eddings v. Oklahoma, 
    455 U.S. 104
     (1982), absent a clear indication in the record that the
    state court applied the wrong standard.
    The en banc court held that the Arizona Supreme Court
    applied an unconstitutional causal nexus test to McKinney’s
    post-traumatic stress disorder—refusing, as a matter of law,
    to treat it as a relevant nonstatutory mitigating factor—
    contrary to clearly established federal law as established in
    Eddings.
    The en banc court held that Eddings error is not structural
    error, but that the Eddings error in this case had a substantial
    and injurious effect on McKinney’s sentence within the
    meaning of Brecht v. Abrahamson, 
    507 U.S. 619
     (1993).
    *
    This summary constitutes no part of the opinion of the court. It has
    been prepared by court staff for the convenience of the reader.
    MCKINNEY V. RYAN                       3
    Judge Bea, joined by Judges Kozinski, Gould, Tallman,
    and Callahan, dissented. He wrote that the majority ignores
    Supreme Court precedent, implicitly overrules this court’s
    precedent, replaces AEDPA’s deferential standard of review
    with an impermissible de novo standard, misstates the record,
    wrongly smears the Arizona Supreme Court, calls into
    question every death sentence imposed in Arizona between
    1989 and 2005 and this court’s cases that have denied habeas
    relief as to those sentences, and brushes by the facts of
    McKinney’s gruesome crimes to find that the error the
    majority has manufactured was prejudicial.
    COUNSEL
    Ivan K. Mathew (argued) and Susan Turner Mathew, Mathew
    and Associates, Phoenix, Arizona, for Petitioner-Appellant.
    Jon Anderson (argued) and Jeffrey A. Zick, Assistant
    Attorneys General, Terry Goddard, Attorney General, and
    Kent Cattani, Chief Counsel, Arizona Attorney General’s
    Office, Criminal Appeals/Capital Litigation Section, Phoenix,
    Arizona, for Respondent-Appellee.
    Michael L. Burke and Robin Konrad, Assistant Federal
    Public Defenders, Jon M. Sands, Federal Public Defender,
    Federal Public Defender’s Office, Phoenix, Arizona, for
    Amicus Curiae Office of the Federal Public Defender.
    4                   MCKINNEY V. RYAN
    OPINION
    W. FLETCHER, Circuit Judge:
    Petitioner James McKinney was sentenced to death, and
    his sentence was affirmed by the Arizona Supreme Court on
    de novo review in 1996. State v. McKinney, 
    917 P.2d 1214
    (Ariz. 1996). A three-judge panel of this court denied
    McKinney’s petition for a writ of habeas corpus. McKinney
    v. Ryan, 
    730 F.3d 903
     (9th Cir. 2013). We granted rehearing
    en banc and withdrew our three-judge panel opinion.
    McKinney v. Ryan, 
    745 F.3d 963
     (9th Cir. 2014). In his
    federal habeas petition, McKinney challenges both his
    conviction and sentence. We agree with the decision of the
    three-judge panel with respect to McKinney’s challenges to
    his conviction, and to that extent we incorporate the decision
    of the panel. We address in this opinion only McKinney’s
    challenge to his death sentence. For the reasons that follow,
    we grant the petition with respect to his sentence.
    In Eddings v. Oklahoma, 
    455 U.S. 104
    , 114 (1982), the
    Supreme Court held under the Eighth and Fourteenth
    Amendments that a sentencer in a capital case may not
    “refuse to consider, as a matter of law, any relevant
    mitigating evidence” offered by the defendant. (Emphasis in
    original.) Oklahoma state courts had refused, as a matter of
    law, to treat as relevant mitigating evidence a capital
    defendant’s background of family violence, including
    beatings by his father, on the ground that “it did not tend to
    provide a legal excuse from criminal responsibility.” 
    Id. at 113
    . The Supreme Court reversed. Recognizing the special
    character of the death penalty, the Court held that evidence of
    Eddings’s background of family violence had to be treated as
    relevant evidence in determining whether to put him to death.
    MCKINNEY V. RYAN                         5
    The Court wrote, “The sentencer, and the Court of Criminal
    Appeals on review, may determine the weight to be given
    relevant mitigating evidence. But they may not give it no
    weight by excluding such evidence from their consideration.”
    
    Id.
     at 114–15.
    At all times relevant to this case, Arizona law provided
    for two kinds of mitigation factors in capital sentencing —
    statutory and nonstatutory. A nonexhaustive list of five
    statutory mitigating factors was provided in 
    Ariz. Rev. Stat. Ann. § 13-703
    (G). Arizona case law applied, in addition,
    nonstatutory mitigating factors, such as a difficult family
    background or a mental condition not severe enough to
    qualify as a statutory mitigating factor.
    For a period of a little over 15 years in capital cases, in
    clear violation of Eddings, the Supreme Court of Arizona
    articulated and applied a “causal nexus” test for nonstatutory
    mitigation that forbade as a matter of law giving weight to
    mitigating evidence, such as family background or mental
    condition, unless the background or mental condition was
    causally connected to the crime. In State v. Wallace,
    
    773 P.2d 983
    , 986 (Ariz. 1989), decided seven years after
    Eddings and four years before petitioner was sentenced, the
    Arizona Supreme Court wrote, “A difficult family
    background, in and of itself, is not a mitigating
    circumstance. . . . A difficult family background is a relevant
    mitigating circumstance if a defendant can show that
    something in that background had an effect or impact on his
    behavior that was beyond the defendant’s control.” In State
    v. Ross, 
    886 P.2d 1354
    , 1363 (Ariz. 1994), decided one year
    after petitioner was sentenced but before his sentence was
    affirmed on appeal, the Arizona Supreme Court wrote, citing
    the precise page in Wallace, “A difficult family background
    6                   MCKINNEY V. RYAN
    is not a relevant mitigating circumstance unless ‘a defendant
    can show that something in that background had an effect or
    impact on his behavior that was beyond the defendant’s
    control.’ State v. Wallace, . . . 
    773 P.2d 983
    , 986 (1989).”
    Two years after its decision in Ross, the Arizona Supreme
    Court affirmed McKinney’s death sentence. In addressing
    the potential mitigating effect of his mental condition, the
    Court wrote that McKinney’s PTSD had no causal nexus to
    his crimes. If anything, the Court wrote, “the effects of [his]
    childhood, specifically the diagnosis of post-traumatic stress
    disorder (PTSD)” would have influenced him not to commit
    the crimes. McKinney, 
    917 P.2d at 1234
    . The Court
    concluded its analysis of McKinney’s PTSD, citing the
    precise page in Ross on which it had articulated the causal
    nexus test for nonstatutory mitigation: “[A] difficult family
    background, including childhood abuse, does not necessarily
    have substantial mitigating weight absent a showing that it
    significantly affected or impacted the defendant’s ability to
    perceive, comprehend, or control his actions. See State v.
    Ross, . . . 
    886 P.2d 1354
    , 1363 (1994).” State v. McKinney,
    
    917 P.2d 1214
    , 1234 (Ariz. 1996).
    For just over fifteen years, the Arizona Supreme Court
    consistently articulated and applied its causal nexus test, in
    accordance with its strong view of stare decisis. See Young
    v. Beck, 
    251 P.3d 380
    , 385 (Ariz. 2011) (“[S]tare decisis
    commands that ‘precedents of the court should not be lightly
    overruled,’ and mere disagreement with those who preceded
    us is not enough.” (quoting State v. Salazar, 
    173 Ariz. 399
    ,
    416 . . . (1992))); State ex re. Woods v. Cohen, 
    844 P.2d 1147
    ,
    1148 (Ariz. 1993) (referring to “a healthy respect for stare
    decisis”); State v. Williker, 
    491 P.2d 465
    , 468 (Ariz. 1971)
    (referring to “a proper respect for the theory of stare
    MCKINNEY V. RYAN                         7
    decisis”); White v. Bateman, 
    358 P.2d 712
    , 714 (Ariz. 1961)
    (prior case law “should be adhered to unless the reasons of
    the prior decisions have ceased to exist or the prior decision
    was clearly erroneous or manifestly wrong”).
    The case before us is unusual. In federal habeas cases
    under the Antiterrorism and Effective Death Penalty Act
    (“AEDPA”), we apply a “presumption that state courts know
    and follow the law” and accordingly give state-court
    decisions “the benefit of the doubt.” Woodford v. Visciotti,
    
    537 U.S. 19
    , 24 (2002). If the Arizona Supreme Court during
    the relevant period had been inconsistent in its articulation
    and application of its unconstitutional “causal nexus” test for
    nonstatutory mitigation, we would give the Court the benefit
    of the doubt and would accord it the presumption that it knew
    and followed governing federal law. But the Arizona
    Supreme Court’s consistent articulation and application of its
    causal nexus test, and its citation in McKinney’s case to the
    specific page of Ross on which it articulated the test, make
    such a course impossible. While Visciotti’s presumption is
    appropriate in the great majority of habeas cases, the
    presumption is rebutted here where we know, based on its
    own words, that the Arizona Supreme Court did not “know
    and follow” federal law.
    The precise question before us is whether the Arizona
    Supreme Court applied its unconstitutional “causal nexus”
    test in affirming McKinney’s death sentence on de novo
    review. We must decide whether, under AEDPA, the
    Arizona Supreme Court refused to give weight, as a matter of
    law, to McKinney’s nonstatutory mitigation evidence of
    PTSD, “contrary to . . . clearly established Federal law, as
    determined by the Supreme Court of the United States.”
    
    28 U.S.C. § 2254
    (d)(1). For the reasons that follow, we
    8                   MCKINNEY V. RYAN
    conclude that it did. We therefore grant the writ with respect
    to petitioner’s sentence.
    I. McKinney’s Crimes, Conviction, and Sentence
    James McKinney and his older half brother, Charles
    Michael Hedlund, committed two burglaries in February and
    March of 1991. One person was shot and killed during each
    of the burglaries. At the time of the crimes, McKinney was
    23 years old. Hedlund was 26 years old. McKinney and
    Hedlund had learned about potential burglary targets from
    their half brother, Christopher Morris, and a friend, Joe
    Lemon, who had suggested Christine Mertens’s home as a
    target. The four of them attempted to burglarize Ms.
    Mertens’s home on February 28, 1991, but Ms. Mertens came
    home and they left to avoid detection. The three half
    brothers, McKinney, Hedlund, and Morris, then committed
    two burglaries at other locations the following day.
    McKinney, Hedlund, and possibly Morris went back to
    Ms. Mertens’s house a little over a week later, on March 9,
    1991. This time, Ms. Mertens was already at home. She was
    beaten and stabbed by one or more of the burglars. One of
    the burglars held Ms. Mertens down on the floor and shot her
    in the back of the head with a handgun, covering the gun with
    a pillow. (Morris turned state’s evidence and testified against
    McKinney and Hedlund. He testified that he was at work at
    Burger King on the night of the Mertens murder, but Burger
    King had no record of him working that night.) McKinney
    and Hedlund later tried unsuccessfully to sell the gun. They
    ultimately disposed of the gun by burying it in the desert.
    Not quite two weeks later, on March 22, 1991, McKinney and
    Hedlund burglarized the home of Jim McClain, from whom
    Hedlund had bought a car several months earlier. Mr.
    MCKINNEY V. RYAN                        9
    McClain was asleep in the bedroom. He was shot in the back
    of the head by either McKinney or Hedlund. The bullet was
    consistent with having been fired from a sawed-off rifle
    owned by Hedlund.
    McKinney and Hedlund were tried together before dual
    juries for the burglaries and homicides. McKinney’s jury
    found him guilty of two first degree murders. Hedlund’s jury
    found him guilty of second degree murder of Ms. Mertens
    and first degree murder of Mr. McClain. On July 23, 1993,
    the trial judge sentenced McKinney to death. The Supreme
    Court decision holding judge-sentencing in capital cases
    unconstitutional was nine years in the future. See Ring v.
    Arizona, 
    536 U.S. 584
     (2002). In the last reasoned state court
    decision, the Arizona Supreme Court, reviewing de novo,
    affirmed McKinney’s conviction and sentence in 1996.
    McKinney, 
    917 P.2d 1214
    . We describe the Arizona Supreme
    Court’s sentencing decision at greater length below.
    McKinney filed for state post-conviction relief. His petition
    was denied by the trial court without an evidentiary hearing.
    The Arizona Supreme Court then summarily denied his
    petition for review.
    II. McKinney’s Family Background
    McKinney suffered a traumatic childhood characterized
    by severe physical and psychological abuse, both by his
    biological parents, James McKinney, Sr. (“James”) and
    Bobbie Jean Morris, and by his stepmother, Shirley Crow
    McKinney. At McKinney’s sentencing hearing, his aunt (his
    father’s sister), Susan Sesate, and his younger sister, Diana
    McKinney, described the abuse.
    10                   MCKINNEY V. RYAN
    Susan and Diana both testified about the squalid
    conditions in which McKinney lived as a child. Susan
    testified that while McKinney’s parents, James and Bobbie,
    were still married, their house was filthy. She testified,
    “[W]hen you walked through the door, it wasn’t nothing to
    see, you know, diapers full of — all around. . . . Everything
    stunk.” James was an alcoholic, and Bobbie left him when
    McKinney was about three years old.
    When Bobbie left James, she took with her their three
    children, Diana, Donna, and McKinney. Susan testified, “She
    ran with them. . . . She ran to a lot of different states. I know
    she went to California first and Kansas twice. California
    again. I know she went through Texas, New Mexico.” James
    pursued and brought Bobbie and the children back to
    Arizona, but “she would run again.” “As soon as he brought
    her back, within a week she’d be gone again to Kansas. She
    had the kids there.” James told McKinney’s presentence
    investigator that Bobbie had “kidnapped” the children, and
    that he took them back “after he found out they were being
    physically abused and were being locked in closets, hungry
    and sick.”
    Bobbie eventually left James for good, and he got
    remarried. James got custody of the children and brought
    them to Arizona to live with him and his new wife Shirley.
    The conditions in the house with James and Shirley were
    even worse than they had been with James and Bobbie.
    Susan, a teenager at the time, lived with her mother (who was
    also James’s mother) in a house nearby. She was at the
    McKinney house frequently. Susan testified that the house
    “was gross. It was gross. I mean, the house was filthy, the
    kids were filthy, they never had clean clothes that I ever saw
    MCKINNEY V. RYAN                        11
    them in. If they had clothes, they were ill-fitting clothes. I
    mean, it was disgusting.”
    McKinney, his two sisters, and his older half brother
    Hedlund (Bobbie’s son by a different father) shared one small
    bedroom. Shirley’s daughter had a bedroom to herself.
    Susan testified that the floor of the four children’s bedroom
    was always covered with dirty clothes because there were no
    bureaus and no hangers for the closet. There were no sheets
    on the beds. The children had to share their room with
    animals Shirley brought home, including dogs, cats, a goat,
    snakes, and a monkey. The animals regularly defecated and
    urinated in the bedroom. Diana testified that the adults never
    cleaned the bedroom.
    Diana was 18 months old when James took the children
    from Bobbie and brought them to the Arizona house he
    shared with his new wife Shirley. Donna was three,
    McKinney was four or five, and Hedlund was seven. Diana
    and Susan testified that the four children were responsible for
    all general household cooking and cleaning, including
    cleaning up the animal feces and urine that were “all over”
    the house; feeding farm animals, including cows, pigs, and
    goats; taking care of James’s hunting dogs; doing all of their
    own laundry; and sometimes doing Shirley’s laundry. Diana
    testified that she and the other children cleaned the house the
    best they could, but “the house still smell[ed]” all the time.
    Susan testified, “It was nothing to see James [Jr.] and Michael
    [Hedlund] standing on chairs at the stove cooking or having
    to stand on chairs to do the dishes” because they were too
    small to reach the stove and the counters. Shirley’s daughter
    did not have to do any chores. Shirley kept the children from
    attending school as punishment for various supposed
    infractions. Susan testified that on one occasion McKinney
    12                  MCKINNEY V. RYAN
    sat on the porch for three days while the others went to
    school. When Susan’s mother (McKinney’s grandmother)
    sent Susan over to investigate, McKinney told her that Shirley
    would not allow him to go to school unless Bobbie bought
    him a new pair of tennis shoes. Susan’s mother bought
    McKinney shoes so he could return to school.
    The children never had regular baths and often had dirty
    hair. When the children went to school, they wore dirty
    clothes that reeked of urine from being on the bedroom floor
    with the animals. The children’s school sent letters home
    about their appearance and odor. They were regularly
    harassed and teased by other children. McKinney was
    frequently suspended for fighting on the school bus because
    other children made fun of his appearance and odor.
    The four children suffered regular and extensive physical,
    verbal, and emotional abuse. Minor infractions of Shirley’s
    rules, such as not doing the dishes properly, resulted in
    beatings. Diana testified that she could not recall a time when
    none of the children had a welt or bruise inflicted by Shirley.
    Susan testified, “They had bruises all the time. It was hard to
    tell what were new bruises and what weren’t.” Shirley used
    plastic switches, cords, belts, and a hose to hit them—
    “anything she could get in her hands.” Diana estimated that
    McKinney was beaten two to three times a week. Susan
    testified to repeated serious beatings, including one particular
    beating with
    [a] water hose. It was about a yard long like
    that (indicating), and she had like a pocket
    knife, and she snipped the hose and she went
    after him. She beat him on the back of the
    head, down his back, all over his legs, his
    MCKINNEY V. RYAN                        13
    arms; anything that moved, she hit him. . . .
    He had bruises for weeks after that all over
    him. . . . Michael Hedlund tried to stop her.
    He grabbed her arm, and so she swung back
    and hit him across the side of the face and
    bruised his face.
    Hedlund left the house to live with his mother when he
    was 14 years old. This left McKinney, approximately age 11,
    as the only boy and the oldest of the three remaining children.
    McKinney was too young to protect either himself or his
    younger sisters. Diana, the younger of the two girls,
    described their childhood experience as “horrible. It was
    scary. It seems like we were all stressed out wondering when
    the next time we were getting beat; wondering when we were
    going to eat next.”
    Shirley’s physical abuse was accompanied by verbal and
    emotional abuse. Diana testified that Shirley regularly yelled
    at them, telling them that they were “[s]tupid, ugly, [and] not
    worth anything.” Diana testified that Shirley showed
    consistent favoritism toward her own daughter, while treating
    her stepchildren as the “four bad kids.”
    Shirley often locked the children out of the house for
    hours without food and, sometimes, water. There was a hose
    in the yard, but Susan testified that if Shirley “was really
    angry at them, they couldn’t turn the water faucet on outside
    and even get a drink of water, and it would be 110 degrees
    outside.” Susan remembered one occasion seeing the four
    children outside on a hot Arizona summer day, clustered in
    the shade of an eave of the house. None of the children had
    shoes; the girls were wearing only underwear, and the boys
    were wearing cutoff shorts with no shirts. When Susan and
    14                  MCKINNEY V. RYAN
    her mother returned to their house four hours later in the
    middle of the afternoon, the children were still there, their
    faces “beet red.” They told her that they were not allowed to
    get any water and could not come back inside until their
    father got home, when he would “punish them.” On another
    occasion, Susan testified, Shirley “pick[ed] James [Jr.] up by
    the scruff of the neck” and put him out on the porch with no
    shoes or coat during the winter, when the frozen grass “would
    crunch under your feet.”
    Shirley spent most of her time at home, while James was
    generally absent. When he was home, James drank heavily.
    Susan testified that James’s mother confronted him about
    Shirley’s physical abuse of the children, but he told her to
    “keep her nose out of his business.” Susan testified to an
    incident in which McKinney, who was in first or second
    grade at the time, had stolen a lunch at school because Shirley
    and James had not given him any lunch money. McKinney
    was suspended for several days. James told his son that “he
    wasn’t going to punish him for stealing lunch; he was going
    to punish him for getting caught.”
    By age nine or 10, McKinney had become distant, quiet
    and withdrawn. He avoided other children. He began using
    alcohol and marijuana at age 11. He dropped out of school in
    the seventh grade. At about this time, he began running away
    from home. Diana testified that McKinney ran away four or
    five times. Susan remembered one incident in which, at age
    11, McKinney showed up unannounced at her house in
    Gilbert, Arizona after traveling alone from Oklahoma, where
    the family had moved. McKinney had taken a bus as far as
    Flagstaff, but did not have enough money to go farther. He
    spent the next two days hitchhiking the rest of the way to
    Susan’s house. McKinney’s arm, shoulder, and face were
    MCKINNEY V. RYAN                        15
    bruised; he told Susan he had gotten into a fight with Shirley.
    Susan called his mother Bobbie on the telephone to tell her
    that McKinney was at her house and that he was dirty and
    tired, and hadn’t eaten in days. Bobbie did not come over to
    pick him up. She called the sheriff instead, who picked up
    McKinney and put him in juvenile detention.
    III. McKinney’s Post-traumatic Stress Disorder
    Dr. Mickey McMahon, a psychologist, made a formal
    diagnosis of PTSD resulting from the horrific childhood
    McKinney had suffered. Before arriving at his diagnosis, Dr.
    McMahon had spent eight and a half hours with McKinney,
    talking to him and administering a battery of tests. He had
    also spoken with Susan for an hour and with Diana for half an
    hour. Finally, Dr. McMahon had listened to Susan and
    Diana’s testimony in court before providing his own
    testimony. When asked, “[D]o you have any doubts about
    your diagnosis of James McKinney having Post-traumatic
    Stress Disorder?” Dr. McMahon answered, “No. None.”
    Dr. McMahon testified that his diagnosis of PTSD rested
    not only on the abuse that McKinney himself had suffered.
    He testified, “We know in research that witnessing can be
    even more damaging than actually being the recipient of
    abuse. . . . [T]here is a helplessness that is involved when
    you’re witnessing . . . violence and you’re too small to do
    anything about it.” When asked whether “violence upon his
    sisters and brother would be . . . more traumatic to him
    possibly than himself,” Dr. McMahon answered, “Yes.” Dr.
    McMahon testified that his interview with McKinney “had
    gone into great depth about him witnessing Dian[]a being
    abused and beaten by her stepmother.”
    16                   MCKINNEY V. RYAN
    Dr. McMahon testified that McKinney’s PTSD was
    characterized by “flashbacks,” by “some sort of voidness,
    numbing, withdrawing,” and by “substance abuse.” The
    substances were “generally downers, opiates in prison,
    alcohol, marijuana.” Dr. McMahon characterized McKinney
    as “basically passive,” “quite submissive,” and “susceptible
    to manipulation, exploitation.” “He can be emotionally
    overwhelmed by environmental stress and act in poorly-
    judged ways just to [re]duce the internal emotional turmoil.”
    “He does not present [i]n the testing [as someone] who is . . .
    manipulative, sensation- or thrill-seeking, and we know often
    that people that get involved with violent kinds of crime are
    thrill-seeking sociopaths. These results do not look like that.
    It looks the opposite of that, since these tests are pretty much
    consistent. He is a lo[]ner; depressed.”
    When asked whether someone with PTSD would “suffer
    . . . constantly” from it, or whether it “may rear its head under
    certain situations,” Dr. McMahon responded that for someone
    with PTSD “there is the potential for the trauma to be re-
    triggered, if things happen that are similar to what happened
    when you’re originally traumatized.” When asked about the
    Mertens burglary and murder, Dr. McMahon testified that if
    an altercation had taken place between Ms. Mertens and
    another person (not necessarily McKinney), it could “very
    possib[ly]” have “re-triggered” McKinney’s trauma and could
    have produced “diminished capacity.”
    When asked about the McClain burglary and murder, Dr.
    McMahon testified that it would have been very
    uncharacteristic of McKinney to have shot a sleeping person.
    “Mr. McKinney’s test[] results, in the more than eight hours
    I spent with him, did not indicate that he was that thrill-
    seeking kind of, execution-kind of person. He’d rather
    MCKINNEY V. RYAN                       17
    withdraw from the situation.” Shooting a sleeping person
    “would be the exact opposite of what I would expect from
    Mr. McKinney.”
    Dr. Steven Gray, also a psychologist, testified for the
    prosecution. In preparation for his testimony, Dr. Gray had
    reviewed two presentence reports, a report prepared by Dr.
    McMahon, the raw data and results of tests performed by Dr.
    McMahon, and McKinney’s school records. He had also
    interviewed McKinney in jail, in the company of one of his
    lawyers, for “an hour, hour-and-a-half.” Dr. Gray had not
    spoken with Susan, Diana, or other family members. Dr.
    Gray testified, “I don’t think there’s enough evidence or
    diagnostic materials or work that’s been done to conclusively
    diagnose [McKinney] as having Post-traumatic Stress
    Disorder.” Dr. Gray’s “tentative or provisional diagnosis”
    was “Antisocial Personality Disorder.”
    IV. Sentencing
    The verdict forms submitted to McKinney’s and
    Hedlund’s juries asked only for general verdicts. The
    prosecutor had argued to the juries that they could find
    McKinney and Hedlund guilty of first degree murder either
    because they were guilty of actually killing Ms. Mertens or
    Mr. McClain, or because they were guilty of felony murder.
    At McKinney’s sentencing hearing, the judge indicated that
    he believed that McKinney had shot Ms. Mertens and that
    Hedlund had shot Mr. McClain. But the judge recognized
    that the jury had not specifically found that McKinney had
    shot Ms. Mertens. The judge therefore relied on Enmund v.
    Florida, 
    458 U.S. 782
     (1982), and Tison v. Arizona, 
    481 U.S. 137
     (1987), to conclude that even if McKinney had not killed
    either Ms. Mertens or Mr. McClain, his involvement in the
    18                   MCKINNEY V. RYAN
    crimes leading up their murders nevertheless made him
    death-eligible. He said with respect to the murder of Ms.
    Mertens, “[E]ven if [Helund] had committed the homicide of
    Mrs. Mertens, [McKinney] knew that [Hedlund] at the time
    of entering the McClain residence was capable of killing.”
    When McKinney was sentenced, Arizona provided by
    statute a nonexhaustive list of five specific mitigating factors.
    See 
    Ariz. Rev. Stat. Ann. § 13-703
    (G) (1993). Among the
    statutory mitigators was a modified form of diminished
    capacity, contained in § 13-703(G)(1): “The defendant’s
    capacity to appreciate the wrongfulness of his conduct or to
    conform his conduct to the requirements of the law was
    significantly impaired, but not so impaired as to constitute a
    defense to prosecution.”
    Arizona law also provided for nonstatutory mitigating
    factors, such as family background or mental conditions that
    did not rise to the level of impairment specified in § 13-
    703(G)(1). For a little over fifteen years, from the late 1980s
    until 2006, Arizona Supreme Court applied a “causal nexus”
    test to nonstatutory mitigation factors. Under this test,
    evidence of a difficult family background or mental disorder
    was not in and of itself a relevant nonstatutory mitigating
    factor. As a matter of Arizona law, such evidence was
    relevant for nonstatutory mitigation only if it had a causal
    effect on the defendant’s behavior in the commission of the
    crime at issue. Application of the causal nexus test to
    nonstatutory mitigation factors violated Eddings, for it
    resulted in Arizona courts being entirely forbidden, as a
    matter of state law, to treat as a mitigating factor a family
    background or a mental condition that was not causally
    connected to a defendant’s crime.
    MCKINNEY V. RYAN                       19
    The trial judge sentenced McKinney to death. The judge
    weighed what he concluded were legally relevant aggravating
    and mitigating circumstances. He stated that “with respect to
    mitigation” he “considered” the exhibits that were admitted
    into evidence, and that he “did take . . . into consideration”
    the testimony of Susan Sestate, Diana McKinney, and Dr.
    McMahon. He stated as to McKinney’s family history, “I
    agree that there was evidence of a difficult family history by
    the defendant. However, as I’ve indicated, I do not find that
    [it] is a substantial mitigating factor . . . .”
    The judge accepted Dr. McMahon’s PTSD diagnosis, but
    concluded that it was not causally connected to McKinney’s
    criminal behavior. Twice the judge specifically addressed the
    relevance of McKinney’s PTSD as a potential mitigating
    factor. Although the judge did not expressly so state, it
    appears (and we are willing to assume) that he was speaking
    both times in the context of statutory mitigation under § 13-
    703(G)(1). The judge gave McKinney’s PTSD no weight as
    a mitigating factor.
    The judge stated:
    But I think more importantly than that,
    certainly not trying to dispute him as an
    expert on what all that meant, it appeared to
    me that Dr. McMahon did not at any time
    suggest in his testimony nor did I find any
    credible evidence to suggest that, even if the
    diagnosis of Post-traumatic Stress Syndrome
    were accurate in Mr. McKinney’s case, that
    [it] in any way significantly impaired Mr.
    McKinney’s conduct.
    20                  MCKINNEY V. RYAN
    (Emphasis added.) He stated a short time (two transcript
    paragraphs) later:
    [I]t appeared to me that based upon all these
    circumstances that there simply was no
    substantial reason to believe that even if the
    trauma that Mr. McKinney had suffered in
    childhood had contributed to an appropriate
    diagnosis of Post-traumatic Stress Syndrome
    that it in any way affected his conduct in this
    case.
    (Emphasis added.) Nowhere else in his sentencing colloquy
    did the judge specifically refer to McKinney’s PTSD and its
    possible mitigating effect.
    The italicized language in two paragraphs just quoted
    echoes the causal nexus test of the statutory mitigating factor
    in § 13-703(G)(1). When applied solely in the context of
    statutory mitigation under § 13-703(G)(1), the causal nexus
    test does not violate Eddings. However, the italicized
    language also echoes the restrictive language of Arizona’s
    causal nexus test applicable to nonstatutory mitigation. When
    applied in the context of nonstatutory mitigation, the causal
    nexus test clearly violates Eddings.
    The Arizona Supreme Court reviews capital sentences de
    novo, making its own determination of what constitute legally
    relevant aggravating and mitigating factors, and then
    independently weighing those factors. 
    Ariz. Rev. Stat. Ann. § 13-755
    ; see also McKinney, 
    917 P.2d at 1225
    . The Arizona
    Supreme Court affirmed McKinney’s death sentence. The
    Court addressed “the effects of [McKinney’s] childhood,
    specifically the diagnosis of post-traumatic stress disorder
    MCKINNEY V. RYAN                        21
    (PTSD).” 
    Id. at 1234
    . The Court agreed with the trial judge
    that there was no causal nexus between McKinney’s PTSD
    and his crimes. Indeed, the Court went further, finding that
    McKinney’s PTSD would have influenced him not to commit
    his crimes.
    In sentencing McKinney to death, the Arizona Supreme
    Court gave no weight to McKinney’s PTSD. It made no
    reference to statutory mitigation under § 13-703(G)(1).
    Instead, the Court recited its unconstitutional causal nexus
    test applicable to nonstatutory mitigation, citing the specific
    page of Ross on which it had articulated that test two years
    earlier. The Court wrote:
    [T]he record shows that the judge gave
    full consideration to McKinney’s childhood
    and the expert testimony regarding the effects
    of that childhood, specifically the diagnosis of
    post-traumatic stress disorder (PTSD).
    Assuming the diagnoses were correct, the
    judge found that none of the experts testified
    to, and none of the evidence showed, that such
    conditions in any way impaired McKinney’s
    ability to conform his conduct to the law. The
    judge noted that McKinney was competent
    enough to have engaged in extensive and
    detailed preplanning of the crimes.
    McKinney’s expert testified that persons with
    PTSD tended to avoid engaging in stressful
    situations, such as these burglaries and
    murders, which are likely to trigger symptoms
    of the syndrome. The judge observed that
    McKinney’s conduct in engaging in the
    crimes was counter to the behavior
    22                  MCKINNEY V. RYAN
    McKinney’s expert described as expected for
    people with PTSD. . . . [A] difficult family
    background, including childhood abuse, does
    not necessarily have substantial mitigating
    weight absent a showing that it significantly
    affected or impacted the defendant’s ability to
    perceive, comprehend, or control his actions.
    See State v. Ross, 
    180 Ariz. 598
    , 607,
    
    886 P.2d 1354
    , 1363 (1994)[.]
    McKinney, 
    917 P.2d at 1234
     (emphasis added).
    V. Deference under AEDPA
    McKinney’s appeal is governed by AEDPA.
    Accordingly, we will not grant his petition for a writ of
    habeas corpus unless the state’s adjudication of his claim
    (1) resulted in a decision that was contrary to,
    or involved an unreasonable application of,
    clearly established Federal law, as determined
    by the Supreme Court of the United States; or
    (2) resulted in a decision that was based on an
    unreasonable determination of the facts in
    light of the evidence presented in the State
    court proceeding.
    
    28 U.S.C. § 2254
    (d). We review de novo the district court’s
    decision whether to grant McKinney’s habeas petition. Dyer
    v. Hornbeck, 
    706 F.3d 1134
    , 1137 (9th Cir. 2013).
    Under the “contrary to” prong of § 2254(d)(1), a federal
    court may grant habeas relief only “if the state court arrives
    MCKINNEY V. RYAN                         23
    at a conclusion opposite to that reached by [the Supreme]
    Court on a question of law or if the state court decides a case
    differently than [the Supreme] Court has on a set of
    materially indistinguishable facts.” Williams v. Taylor,
    
    529 U.S. 362
    , 413 (2000). Under the “unreasonable
    application” prong, a federal court may grant relief only if
    “the state court’s application of clearly established federal
    law was objectively unreasonable,” 
    id. at 409
    , such that
    “fairminded jurists could [not] disagree that” the arguments
    or theories that supported the state court’s decision were
    “inconsistent with the holding in a prior decision of [the
    Supreme] Court,” Harrington v. Richter, 
    562 U.S. 86
    , 102
    (2011) (internal quotation marks omitted).
    For purposes of habeas review, we review the state
    court’s “last reasoned decision.” Dyer, 706 F.3d at 1137. We
    apply a “presumption that state courts know and follow the
    law.” Visciotti, 
    537 U.S. at 24
    . “[Section] 2254(d)’s ‘highly
    deferential standard for evaluating state-court rulings’ . . .
    demands that state-court decisions be given the benefit of the
    doubt.” 
    Id.
     We “are not free to presume that a state court did
    not comply with constitutional dictates on the basis of
    nothing more than a lack of citation.” Bell v. Cone, 
    543 U.S. 447
    , 455 (2005); see also Early v. Packer, 
    537 U.S. 3
    , 8
    (2002) (“[AEDPA] does not require citation of our
    cases—indeed, it does not even require awareness of our
    cases, so long as neither the reasoning nor the result of the
    state-court decision contradicts them.”). We should neither
    engage in hyper-technical analysis nor require “formulary
    statement[s]” that ignore “the fair import of the [state court’s]
    opinion.” Packer, 537 U.S. at 9. Our task is to determine
    what standard the state court actually applied to resolve the
    petitioner’s claim. See Lafler v. Cooper, 
    132 S. Ct. 1376
    ,
    1390 (2012).
    24                  MCKINNEY V. RYAN
    VI. Clearly Established Law as Determined by the
    Supreme Court
    The Supreme Court in Lockett v. Ohio, 
    438 U.S. 586
    (1978), and in Eddings established a clear rule governing the
    role of mitigating evidence in capital sentencing. In Lockett,
    Chief Justice Burger wrote a plurality opinion concluding that
    Ohio’s death penalty statute was invalid because it restricted
    the mitigating circumstances that could be considered by the
    sentencer. The plurality concluded that under the Eighth and
    Fourteenth Amendments, “the sentencer . . . [must] not be
    precluded from considering, as a mitigating factor, any aspect
    of a defendant’s character or record and any of the
    circumstances of the offense that the defendant proffers as a
    basis for a sentence less than death” because a rule preventing
    “the sentencer in all capital cases from giving independent
    mitigating weight to aspects of the defendant’s character and
    to circumstances of the offense proffered in mitigation creates
    the risk that the death penalty will be imposed in spite of
    factors which may call for a less severe penalty.” 
    438 U.S. at
    604–05 (emphasis in original).
    Four years later, in Eddings, the Court applied the
    principle articulated in Chief Justice Burger’s opinion in
    Lockett. In Eddings, the sentencing judge had refused to
    consider evidence that Eddings had been raised in turbulent
    homes without supervision, had witnessed his mother’s
    substance abuse, and had been beaten by his father. After
    “weigh[ing] the evidence of aggravating and mitigating
    circumstances,” the sentencing judge concluded that he could
    not, “in following the law . . . consider the fact of this young
    man’s violent background.” 
    455 U.S. at
    108–09. Although
    the state appeals court acknowledged Eddings’s family
    history and psychological and emotional disorders, it upheld
    MCKINNEY V. RYAN                        25
    his conviction because “all the evidence tends to show that
    [Eddings] knew the difference between right and wrong at the
    time he pulled the trigger, and that is the test of criminal
    responsibility in this State.” 
    Id.
     at 109–10. The Supreme
    Court endorsed the plurality opinion in Lockett and held that
    [j]ust as the State may not by statute preclude
    the sentencer from considering any mitigating
    factor, neither may the sentencer refuse to
    consider, as a matter of law, any relevant
    mitigating evidence. . . . The sentencer, and
    the Court of Criminal Appeals on review, may
    determine the weight to be given relevant
    mitigating evidence. But they may not give it
    no weight by excluding such evidence from
    their consideration.
    
    Id.
     at 113–15 (emphasis in original).
    The United States Supreme Court interpreted and applied
    the Lockett/Eddings rule in several other decisions prior to
    McKinney’s sentencing in 1993 and the Arizona Supreme
    Court’s affirmance in 1996. In those decisions, the Court
    reiterated its holding that the admission of relevant evidence
    is not enough to satisfy the Eighth and Fourteenth
    Amendments if the sentencer is prevented by state law from
    giving effect to that evidence. Because “full consideration of
    evidence that mitigates against the death penalty is essential
    if the [sentencer] is to give a ‘reasoned moral response to the
    defendant’s background, character, and crime,’” Eddings
    requires that “[t]he sentencer must also be able to consider
    and give effect to that evidence in imposing sentence.” Penry
    v. Lynaugh (Penry I), 
    492 U.S. 302
    , 319, 328 (1989),
    abrogated on other grounds by Atkins v. Virginia, 
    536 U.S. 26
                       MCKINNEY V. RYAN
    304 (2002) (quoting Franklin v. Lynaugh, 
    487 U.S. 164
    , 184
    (1988) (O’Connor, J., concurring in the judgment)). “[T]he
    State cannot channel the sentencer’s discretion, but must
    allow it to consider any relevant information offered by the
    defendant.” McCleskey v. Kemp, 
    481 U.S. 279
    , 306 (1987);
    see also Skipper v. South Carolina, 
    476 U.S. 1
    , 4–5 (1986)
    (holding that even where mitigating evidence does “not relate
    specifically to . . . [the defendant’s] culpability for the crime
    he committed,” the defendant is entitled to offer any evidence
    that “would be ‘mitigating’ in the sense that they might serve
    ‘as a basis for a sentence less than death’” (quoting Lockett,
    
    438 U.S. at 604
    )).
    VII. The Causal Nexus Test and Its Application Here
    A. Arizona’s Test
    The trial judge sentenced McKinney to death in 1993.
    The Arizona Supreme Court affirmed Kinney’s conviction
    and sentence in 1996.
    As briefly described above, Arizona capital sentencing
    law included a statutorily specified nonexhaustive list of five
    mitigating factors. See 
    Ariz. Rev. Stat. Ann. § 13-703
    (G)
    (1993). Among the statutory mitigating factors was a
    modified form of diminished capacity, contained in § 13-
    703(G)(1): “The defendant’s capacity to appreciate the
    wrongfulness of his conduct or to conform his conduct to the
    requirements of the law was significantly impaired, but not so
    impaired as to constitute a defense to prosecution.”
    Arizona capital sentencing law also included nonstatutory
    mitigating factors, such as family background or mental
    conditions that did not rise to the level of impairment
    MCKINNEY V. RYAN                        27
    specified in § 13-703(G)(1). Beginning in the late 1980s,
    Arizona Supreme Court developed a “causal nexus” test for
    nonstatutory mitigation. Under this test, as we noted above,
    evidence of a difficult family background or a mental
    condition was not in and of itself relevant mitigating
    evidence. As a matter of Arizona law, such evidence was
    relevant for mitigation purposes only if it had some causal
    effect contributing to the defendant’s behavior in the
    commission of the crime at issue. Thus, while the defendant
    could submit evidence of his difficult family background or
    mental condition, the sentencing court was prohibited from
    treating it as legally relevant mitigation evidence unless the
    defendant proved a causal connection between his
    background or disorder and the crime. In capital cases from
    the late 1980s to the mid-2000s, the Arizona Supreme Court
    repeatedly articulated this causal nexus test for nonstatutory
    mitigation. The test was “contrary to . . . clearly established
    Federal law, as determined by the Supreme Court of the
    United States” in Eddings.
    In the immediate aftermath of Eddings, the Arizona
    Supreme Court had not yet developed its causal nexus test for
    nonstatutory mitigation. One year after Eddings, the Arizona
    Supreme Court understood and applied Eddings and Lockett
    correctly. In State v. McMurtrey, a capital case, the Court
    wrote:
    [T]he sentencer may not refuse to consider, as
    a matter of law, relevant evidence presented in
    mitigation. Eddings v. Oklahoma, 
    455 U.S. 104
    , 
    102 S.Ct. 869
    , 
    71 L.Ed.2d 1
     (1982). . . .
    . . . If after considering the offered
    evidence, the court concludes that with
    28                 MCKINNEY V. RYAN
    respect to the defendant’s mental condition, it
    merely establishes a character or personality
    disorder then the court may under [State v.]
    Richmond, [
    560 P.2d 41
     (Ariz. 1976),]
    conclude that the mitigating circumstance in
    [Ariz. Rev. Stat. Ann.] § 13-703(G)(1) does
    not exist. In order to remain faithful to
    Lockett and [State v.] Watson, [
    586 P.2d 1253
    (Ariz. 1978),] however, the court’s inquiry
    may not end there. The court must consider
    the offered evidence further to determine
    whether it in some other way suggests that the
    defendant should be treated with leniency.
    
    664 P.2d 637
    , 646 (Ariz. 1983); see also State v. Gretzler,
    
    659 P.2d 1
    , 14 (Ariz. 1983).
    By the late 1980s, however, the Arizona Supreme Court
    had begun to articulate and apply its causal nexus test to
    nonstatutory mitigation. In Wallace, decided three years
    before the trial judge sentenced McKinney, the Arizona
    Supreme Court wrote in a capital case:
    A difficult family background, in and of
    itself, is not a mitigating circumstance. If it
    were, nearly every defendant could point to
    some circumstance in his or her background
    that would call for mitigation. A difficult
    family background is a relevant mitigating
    circumstance if a defendant can show that
    something in that background had an effect or
    impact on his behavior that was beyond the
    defendant’s control. . . . [Appellant’s] entire
    family background was before the court in the
    MCKINNEY V. RYAN                       29
    pre-sentence report. Appellant, however,
    made no claim that his family background had
    anything to do with the murders he committed.
    Wallace, 
    773 P.2d at 986
     (1989) (emphasis added). The
    Court could not have been clearer that, as a matter of law,
    nonstatutory mitigation evidence not satisfying the causal
    nexus test was irrelevant.     This test was in direct
    contravention of Eddings and Lockett.
    In Ross, decided two years after the trial judge sentenced
    McKinney, the Arizona Supreme Court wrote in another
    capital case, with a pin citation to the precise page in
    Wallace:
    A difficult family background is not a
    relevant mitigating circumstance unless “a
    defendant can show that something in that
    background had an effect or impact on his
    behavior that was beyond the defendant’s
    control.” State v. Wallace, 
    773 P.2d 983
    , 986
    (Ariz. 1989).
    
    886 P.2d at 1363
     (1994) (citation shortened) (emphasis
    added). Again, the Court could not have been clearer that, as
    a matter of law, nonstatutory mitigation evidence not
    satisfying the causal nexus test was irrelevant. In affirming
    McKinney’s death sentence in 1996, the Arizona Supreme
    Court cited Ross, with a pin citation to this precise page.
    McKinney, 
    917 P.2d at 1234
    .
    Two years after affirming McKinney’s death sentence, the
    Arizona Supreme Court mentioned Eddings by name, in a
    passage manifesting its continued misreading of Eddings and
    30                   MCKINNEY V. RYAN
    Lockett. In State v. Djerf, 
    959 P.2d 1274
    , 1289 (Ariz. 1998),
    the Arizona Supreme Court explained that it read Eddings
    and Lockett to require a sentencer to “consider” evidence
    offered in mitigation. In the usage of the Arizona Court,
    however, “considering” such evidence did not mean weighing
    it to determine how much mitigating effect to give it. Rather,
    it meant “considering” such evidence to determine whether it
    satisfied the causal nexus test for nonstatutory mitigation. If
    it satisfied the test, the sentencer was required to determine
    how much weight, if any, to give it. If did not satisfy the test,
    the sentencer was required, as a matter of law, to treat it as
    irrelevant and to give it no weight. As the Court wrote in
    Djerf:
    This court has held that Lockett and Eddings
    require only that the sentencer consider
    evidence proffered for mitigation. The
    sentencer, however, is entitled to give it the
    weight it deserves. Arizona law states that a
    difficult family background is not relevant
    unless the defendant can establish that his
    family experience is linked to his criminal
    behavior. Ross, 
    886 P.2d at 1362
    . The trial
    court considered the evidence but found it
    irrelevant and declined to give it weight
    because proof was lacking that his family
    background had any effect on the crimes.
    
    Id.
     (emphasis added and some citations omitted).
    Two years later, in State v. Hoskins, the Arizona Supreme
    Court reiterated what it had written in Djerf and explained the
    Arizona causal nexus test and its two-step process for
    MCKINNEY V. RYAN                       31
    “consideration” of mitigating evidence. The Court wrote at
    length:
    The trial court found that defendant had
    shown by a preponderance of the evidence
    that he suffered from antisocial or borderline
    personality disorder. But proof that such
    disorder exists does not of itself establish
    mitigation. For our purposes on review, it is
    essential not only that a personality disorder
    be shown to exist but that it be causally linked
    to the crime at the time the crime is
    committed.
    ...
    A dysfunctional family background or
    difficult childhood can be mitigating only if
    the defendant can establish that early
    experiences, however negative, affected later
    criminal behavior in ways that were beyond
    his control. Thus, family dysfunction, as with
    mental impairment under the (G)(1) statute,
    can be mitigating only when actual causation
    is demonstrated between early abuses suffered
    and the defendant’s subsequent acts. We
    reaffirm that doctrine here. . . .
    . . . If the defendant fails to prove
    causation, the circumstance will not be
    considered mitigating. However, if the
    defendant proves the causal link, the court
    will then determine what, if any, weight to
    accord the circumstance in mitigation.
    32                  MCKINNEY V. RYAN
    ....
    The dissenting opinion expresses an
    impassioned description of the defendant’s
    “horrific” childhood. We are aware of the
    circumstances of defendant’s upbringing and
    have reviewed all aspects in minute detail.
    . . . Yet, it is clear that credible evidence in
    this record does not establish actual nexus
    with the crime, and our jurisprudence requires
    the nexus be proven. Wallace (II), 
    773 P.2d at
    985–86. Importantly, were we to hold
    otherwise, the family dysfunction factor and
    the impairment factor would become
    meaningless because virtually every homicide
    defendant can point to background
    dysfunction, abuse, or neglect as a basis for
    mitigation and leniency.
    
    14 P.3d 997
    , 1021–22 (Ariz. 2000) (emphasis added and
    some citations omitted).
    The decisions of the Arizona Supreme Court make clear
    that family background or a mental condition could be given
    weight as a nonstatutory mitigating factor, but only if
    defendant established a causal connection between the
    background or condition and his criminal behavior. For a
    little over fifteen years, the Arizona Supreme Court routinely
    articulated and insisted on its unconstitutional causal nexus
    test, as seen in Wallace (1989), Ross (1994), Djerf (1998),
    and Hoskins (2000), as just described, and in many other
    cases. See, e.g., State v. White, 
    815 P.2d 869
    , 881 (Ariz.
    1991) (“‘A difficult family background, in and of itself, is not
    a mitigating circumstance.’” (quoting Wallace, 773 P.2d at
    MCKINNEY V. RYAN                       33
    986)); State v. Brewer, 
    826 P.2d 783
    , 802 (Ariz. 1992) (“The
    evidence of defendant’s troubled background establishes only
    that a personality disorder exists. It does not prove that, at
    the time of the crime, the disorder controlled defendant’s
    conduct or impaired his mental capacity to such a degree that
    leniency is required.”); State v. Bible, 
    858 P.2d 1152
    , 1209
    (Ariz. 1993) (holding that the defendant’s family history was
    not mitigating in part because “Defendant made no showing
    that any difficult family history had anything to do with the
    murder” (citing Wallace, 
    773 P.2d at 986
    )); State v. Bolton,
    
    896 P.2d 830
    , 854 (Ariz. 1995) (“A difficult family
    background, however, is not always a mitigating
    circumstance. If it were, many homicide defendants could
    point to some circumstance in their background that would
    call for mitigation. A difficult family background is a
    mitigating circumstance if a defendant can show that
    something in that background had an effect or impact on his
    behavior that was beyond his control.” (citing Wallace,
    
    773 P.2d at 986
    )); State v. Stokley, 
    898 P.2d 454
    , 473 (Ariz.
    1995) (“A difficult family background alone is not a
    mitigating circumstance.” (citing Wallace, 
    773 P.2d at 986
    ));
    State v. Jones, 
    917 P.2d 200
    , 219–20 (Ariz. 1996)
    (defendant’s “chaotic and abusive childhood [was] not a
    mitigating circumstance” because there was no causal nexus
    to the crime); State v. Towery, 
    920 P.2d 290
    , 311 (Ariz. 1996)
    (“We have held that a difficult family background is not
    always entitled to great weight as a mitigating circumstance.
    State v. Wallace, [
    773 P.2d at
    985–86] (‘A difficult family
    background is a relevant mitigating circumstance if a
    defendant can show that something in that background had an
    effect or impact on his behavior that was beyond the
    defendant’s control.’)”); State v. Rienhardt, 
    951 P.2d 454
    ,
    467 (Ariz. 1997) (“[T]his court has rejected past drug and
    alcohol use as a mitigating circumstance calling for leniency
    34                  MCKINNEY V. RYAN
    when there is no evidence of a causal connection between the
    substance abuse and the crime.”); State v. Greene, 
    967 P.2d 106
    , 117 (Ariz. 1998) (“Greene’s mother may have
    introduced him to drugs, but Greene failed to show how this
    influenced his behavior on the night of the murder. Thus, we
    do not find Greene’s dysfunctional family history to be a
    mitigating circumstance.” (internal citation omitted)); State
    v. Sharp, 
    973 P.2d 1171
    , 1182 (Ariz. 1999) (“[W]e require a
    causal connection to justify considering evidence of a
    defendant’s background as a mitigating circumstance.”); State
    v. Kayer, 
    984 P.2d 31
    , 46 (Ariz. 1999) (holding that the
    defendant’s mental impairment “was not established as a
    nonstatutory mitigating factor” in part because “defendant
    offered no evidence to show the requisite causal nexus that
    mental impairment affected his judgment or his actions at the
    time of the murder”); State v. Martinez, 
    999 P.2d 795
    , 809
    (Ariz. 2000) (“There is simply no nexus between Martinez’
    family history and his actions on the Beeline Highway. His
    family history, though regrettable, is not entitled to weight as
    a non-statutory mitigating factor.”); State v. Canez, 
    42 P.3d 564
    , 594 (Ariz. 2002) (“[A] causal nexus between the
    intoxication and the offense is required to establish non-
    statutory impairment mitigation.”); 
    id. at 595
     (“A defendant’s
    difficult childhood is mitigating only where causally
    connected to his offense.”).
    The Arizona Supreme Court articulated the causal nexus
    test in various ways but always to the same effect: As a
    matter of law, a difficult family background or mental
    condition did not qualify as a nonstatutory mitigating factor
    unless it had a causal effect on the defendant’s behavior in
    committing the crime at issue. The Arizona Court frequently
    stated categorically that, absent a causal nexus, would-be
    nonstatutory mitigation was simply “not a mitigating
    MCKINNEY V. RYAN                       35
    circumstance.” Wallace, 
    773 P.2d at 986
    . Sometimes, the
    court stated that evidence offered as nonstatutory mitigation
    that did not have a causal connection to the crime should be
    given no “weight.” For example, as it wrote in Djerf:
    Arizona law states that a difficult family
    background is not relevant unless the
    defendant can establish that his family
    experience is linked to his criminal behavior.
    The trial court considered the evidence but
    found it irrelevant and declined to give it
    weight because proof was lacking that his
    family background had any effect on the
    crimes.
    Djerf, 
    959 P.2d at 1289
     (citation omitted). Similarly, the
    court wrote in Martinez, “There is simply no nexus between
    Martinez’ family history and his actions on the Beeline
    Highway. His family history, though regrettable, is not
    entitled to weight as a non-statutory mitigating factor.”
    Martinez, 
    999 P.2d at 809
    .
    Sometimes, the Arizona Supreme Court stated that
    evidence of a difficult family background or mental illness
    was “not necessarily” or not “usually” mitigating, and then
    (often in the same paragraph) held as a matter of law that the
    evidence in the specific case before the Court was not
    mitigating because it had no causal connection to the crime.
    For example, the Court wrote in Jones,
    A difficult family background is not
    necessarily a mitigating circumstance unless
    defendant can show that something in his
    background had an effect on his behavior that
    36                  MCKINNEY V. RYAN
    was beyond his control. . . . [H]owever, the
    trial court did not find any connection
    between defendant’s family background and
    his conduct on the night of the murders, and
    our review of the record does not reveal any
    such connection.      Thus, we find that
    defendant’s chaotic and abusive childhood is
    not a mitigating circumstance.
    Jones, 917 P.2d at 219–20 (emphasis added).
    Similarly, the Court wrote in Hoskins, quoting an earlier
    case, “‘An abusive family background is usually given
    significant weight as a mitigating factor only when the abuse
    affected the defendant’s behavior at the time of the crime.’”
    Hoskins, 
    14 P.3d at 1021
     (emphasis added) (quoting State v.
    Mann, 
    934 P.2d 784
    , 795 (Ariz. 1997)). The court in Hoskins
    then went to state and apply the unconstitutional causal nexus
    test as a matter of law to the evidence in the case before it,
    writing,
    [I]t is essential not only that a personality
    disorder be shown to exist but that it be
    causally linked to the crime at the time the
    crime is committed. . . .
    . . . Because defendant has not connected
    his anti-social or personality disorder to the
    car-jacking and murder, it cannot be
    co nsidered a relevant m i t i gat i ng
    circumstance. . . .
    ....
    MCKINNEY V. RYAN                       37
    . . . If the defendant fails to prove
    causation, the circumstance will not be
    considered mitigating. However, if the
    defendant proves the causal link, the court
    then will determine what, if any, weight to
    accord the circumstance in mitigation.
    
    Id.
     at 1021–22 (emphasis added).
    In the mid-2000s, after the United States Supreme Court
    emphatically reiterated the Eddings rule in Tennard v. Dretke,
    
    542 U.S. 274
     (2004), the Arizona Supreme Court finally
    abandoned its unconstitutional causal nexus test for
    nonstatutory mitigation. In its first post-Tennard case
    addressing Eddings, the Arizona Supreme Court properly
    stated the rule in a jury sentencing case:
    While Eddings and various other Supreme
    Court decisions dictate a liberal rule of
    admissibility for mitigating evidence, they
    still leave it to the sentencer to “determine the
    weight to be given to relevant mitigating
    evidence.” Eddings, 
    455 U.S. at
    114–15, 
    102 S.Ct. 869
    . Once the jury has heard all the
    defendant’s mitigation evidence, there is no
    constitutional prohibition against the State
    arguing that the evidence is not particularly
    relevant or that it is entitled to little weight.
    State v. Anderson, 
    111 P.3d 369
    , 392 (Ariz. 2005). A year
    later, in a judge-sentencing case, the Arizona Supreme Court,
    relying on Anderson, again properly stated the rule:
    38                 MCKINNEY V. RYAN
    We do not require that a nexus between the
    mitigating factors and the crime be
    established before we consider the mitigation
    evidence. See Tennard v. Dretke, 
    542 U.S. 274
    , 287, 
    124 S.Ct. 2562
    , 
    159 L.Ed.2d 384
    (2004). But the failure to establish such a
    causal connection may be considered in
    assessing the quality and strength of the
    mitigation evidence.
    State v. Newell, 
    132 P.3d 833
    , 849 (Ariz. 2006).
    B. Our “Clear Indication” Test
    Not counting the case now before us, we have decided
    nine Arizona capital cases in which petitioners have alleged
    that the Arizona Supreme Court, as a matter of law, treated
    would-be mitigation evidence as legally irrelevant in
    violation of Eddings. In two of these cases, we held that the
    Arizona Supreme Court committed Eddings error. See
    Williams v. Ryan, 
    623 F.3d 1258
     (9th Cir. 2010); Styers v.
    Schriro, 
    547 F.3d 1026
     (9th Cir. 2008) (per curiam). In the
    other seven, we held that the Arizona Court had not
    committed Eddings error. In six of these, we applied a test
    first articulated in Schad v. Ryan, 
    581 F.3d 1019
    , 1037 (9th
    Cir. 2009) (per curiam) (unamended opinion), under which
    we could not find Eddings error unless there was a “clear
    indication in the record” that the Arizona Court had refused,
    as a matter of law, to treat nonstatutory mitigation evidence
    as relevant unless it had some effect on the petitioner’s
    criminal behavior. See Hedlund v. Ryan, 
    750 F.3d 793
    , 818
    (9th Cir. 2014); Murray v. Schriro, 
    746 F.3d 418
    , 455 (9th
    Cir. 2014); Clabourne v. Ryan, 
    745 F.3d 362
    , 373 (9th Cir.
    2014) (petition for panel rehearing and for rehearing en banc
    MCKINNEY V. RYAN                         39
    pending); Poyson v. Ryan, 
    743 F.3d 1185
    , 1188 (9th Cir.
    2013); Lopez v. Ryan, 
    630 F.3d 1198
    , 1203 (9th Cir. 2011);
    Schad v. Ryan, 
    671 F.3d 708
    , 724 (9th Cir. 2011) (per
    curiam) (amended opinion). In the seventh, we did not apply
    the “clear indication” test. See Towery v. Ryan, 
    673 F.3d 933
    (9th Cir. 2012). In none of the cases in which we held that
    there had been no Eddings error did we hold that the Arizona
    Supreme Court had renounced its causal nexus test. Rather,
    we held only that petitioners had not shown that the Court
    had applied the test in such a way as to treat nonstatutory
    mitigation evidence irrelevant as a matter of law.
    In our amended opinion in Schad, we stated the “clear
    indication” test as follows:
    Absent a clear indication in the record
    that the state court applied the wrong
    standard, we cannot assume the courts
    violated Edding’s constitutional mandates.
    See Bell v. Cone, [
    543 U.S. 447
    , 455] (2005)
    (“Federal courts are not free to presume that a
    state court did not comply with constitutional
    dictates on the basis of nothing more than a
    lack of citation.”).
    Schad, 
    671 F.3d at 724
     (emphasis added). The language from
    Bell, quoted in Schad in support of its “clear indication” rule,
    states only that we may not presume that a state court failed
    to follow federal constitutional law based on “nothing more
    than a lack of citation.” But in Schad we broadened the
    language from Bell and transformed it into a prohibition
    against an “assumption” of unconstitutionality in the absence
    of a “clear indication” to the contrary.
    40                   MCKINNEY V. RYAN
    When used in Bell, the quoted language stated a rule that
    is applicable in a narrow circumstance: a federal habeas court
    should not presume, merely because a state court has failed
    to cite a federal case, that the state court was unaware of or
    failed to follow the rule established in that case. The Bell rule
    is eminently sensible. A presumption of ignorance or
    disregard of federal law based merely on a failure of citation
    by a busy state court is both unrealistic and disrespectful. But
    the Bell rule, as stated by the Supreme Court, has a relatively
    narrow application. It is not a broad rule requiring federal
    habeas courts to assume in all circumstances, including
    Eddings cases, that absent a “clear indication” to the contrary,
    a state understood and properly applied federal law.
    Congress knows how to limit federal collateral review by
    requiring deference to state court decisions, and it has done
    so in AEDPA. Under 
    28 U.S.C. § 2254
    (d), federal courts
    shall not issue writs of habeas corpus on any claim
    adjudicated in state court unless the adjudication “resulted in
    a decision that was contrary to, or involved an unreasonable
    application of, clearly established Federal law” or “that was
    based on an unreasonable determination of the facts in light
    of the evidence presented in the State court proceeding.”
    Section 2254(d) is already a form of a clear statement or a
    clear indication rule, which all federal courts are required to
    follow. The “clear indication” rule stated by our circuit for
    the first time in Schad, and applicable in our circuit only in
    Eddings cases, is an inappropriate and unnecessary gloss on
    the deference already required under § 2254(d). We therefore
    overrule Schad, and the cases that have followed it, with
    respect to the “clear indication” test.
    MCKINNEY V. RYAN                         41
    C. Application of the Causal Nexus Test in This Case
    For the reasons that follow, we conclude that the Arizona
    Supreme Court applied its unconstitutional causal nexus test
    to McKinney’s PTSD, refusing, as a matter of law, to treat it
    as a relevant nonstatutory mitigating factor. This was
    contrary to clearly established federal law as established in
    Eddings.
    We review the decision of the highest state court to have
    provided a reasoned decision. Ylst v. Nunnemaker, 
    501 U.S. 797
    , 804–06 (1991). The Arizona Supreme Court reviews
    capital sentences de novo, making its own determination of
    what constitute legally relevant aggravating and mitigating
    factors, and then weighing those factors independently. 
    Ariz. Rev. Stat. Ann. § 13-755
    . The Arizona Supreme Court
    “conducts a thorough and independent review of the record
    and of the aggravating and mitigating evidence to determine
    whether the sentence is justified.” McKinney, 
    917 P.2d at 1225
    . The Court “considers the quality and strength, not
    simply the number, of aggravating or mitigating factors.” 
    Id.
    In reviewing the de novo sentencing decision of the
    Arizona Supreme Court, we look only to the decision of that
    Court. We look to the decision of the sentencing judge only
    to the degree it was adopted or substantially incorporated by
    the Arizona Supreme Court. See Barker v. Fleming, 
    423 F.3d 1085
    , 1903 (9th Cir. 2005) (holding that when “the last
    reasoned decision adopted or substantially incorporated the
    reasoning from a previous decision,” it is “reasonable for the
    reviewing court to look at both decisions to fully ascertain the
    reasoning of the last decision”). The sentencing judge
    accepted the factual accuracy of Dr. McMahon’s diagnosis of
    PTSD, saying that he was “certainly not trying to dispute him
    42                  MCKINNEY V. RYAN
    as an expert on what all that meant.” The judge then went on
    to say that “Dr. McMahon did not at any time suggest in his
    testimony nor did I find any credible evidence to suggest that,
    even if the diagnosis of Post-traumatic Stress Syndrome were
    accurate in Mr. McKinney’s case, that it in any way
    significantly impaired Mr. McKinney’s conduct.” (Emphasis
    added.) He further stated:
    [I]t appeared to me that based upon all these
    circumstances that there simply was no
    substantial reason to believe that even if the
    trauma that Mr. McKinney had suffered in
    childhood had contributed to an appropriate
    diagnosis of Post-traumatic Stress Syndrome
    that it in any way affected his conduct in this
    case.
    (Emphasis added.) The italicized language echoes the
    language of Arizona’s statutory mitigator under 
    Ariz. Rev. Stat. § 13-703
    (G)(1). It also echoes the language used by the
    Arizona Supreme Court to articulate the unconstitutional
    causal nexus test applied to nonstatutory mitigation. See, e.g.,
    Wallace, 
    773 P.2d at 986
     (“A difficult family background is
    a relevant mitigating circumstance if a defendant can show
    that something in that back ground had an effect or impact on
    his behavior that was beyond his control.”) (emphasis added).
    The Arizona Supreme Court affirmed McKinney’s death
    sentence in 1996, roughly in the middle of the fifteen-year-
    plus period during which it insisted on its unconstitutional
    nexus test for nonstatutory mitigation. The Court reviewed
    in its opinion the death sentences of both Hedlund and
    McKinney. The Court first affirmed Hedlund’s death
    sentence, writing, “A difficult family background, including
    MCKINNEY V. RYAN                         43
    childhood abuse, does not necessarily have substantial
    mitigating weight absent a showing that it significantly
    affected or impacted a defendant’s ability to perceive, to
    comprehend, or to control his actions. See State v. Ross, . . .
    
    886 P.2d 1354
    , 1363 (1994).” McKinney, 
    917 P.2d at 1226
    .
    As we pointed out above, the pin citation to Ross is a citation
    to the precise page on which the Arizona Supreme Court had
    two years earlier articulated its unconstitutional “causal
    nexus” test for non-statutory mitigation.
    When the Arizona Supreme Court reviewed McKinney’s
    death sentence, it again relied on Ross. The Court wrote that
    the sentencing judge had given “full consideration” to
    McKinney’s childhood and resulting PTSD, using the word
    “consideration” in the sense of considering whether the
    evidence was, or was not mitigating. See Djerf, 
    959 P.2d at 1289
     (“This court has held that Lockett and Eddings require
    only that the sentencer consider evidence proffered for
    mitigation. The sentencer, however, is entitled to give it the
    weight it deserves. Arizona law states that a difficult family
    background is not relevant unless the defendant can establish
    that his family experience is linked to his criminal behavior.”)
    (emphasis added).
    Reviewing McKinney’s sentence de novo, the Arizona
    Supreme Court addressed “the effects of [McKinney’s]
    childhood, specifically the diagnosis of post-traumatic stress
    disorder (PTSD).” McKinney, 917 P.2d at 1234. The Court
    accepted the conclusion of the sentencing judge that, as a
    factual matter, McKinney had not shown that his PTSD had
    causally contributed to the murders of Mertens and McClain.
    Indeed, the Arizona Supreme Court went further, pointing out
    that McKinney’s PTSD, if anything, would have had the
    opposite effect, influencing him not to have committed the
    44                  MCKINNEY V. RYAN
    murders. Because the Court concluded that McKinney’s
    PTSD was not causally connected to his crimes, it refused, as
    a matter of law, to treat his PTSD as a mitigating factor.
    After describing McKinney’s PTSD evidence and assessing
    de novo the effect of his PTSD on his behavior, the Court
    recited its causal nexus test. The Court concluded with a pin
    citation to the precise page in Ross on which, two years
    earlier, it had articulated the causal nexus test for
    nonstatutory mitigation.
    We quote in full the relevant paragraph:
    Here again, the record shows that the
    judge gave full consideration to McKinney’s
    childhood and the expert testimony regarding
    the effects of that childhood, specifically the
    diagnosis of post-traumatic stress disorder
    (PTSD). Assuming the diagnoses were
    correct, the judge found that none of the
    experts testified to, and none of the evidence
    showed, that such conditions in any way
    impaired McKinney’s ability to conform his
    conduct to the law. The judge noted that
    McKinney was competent enough to have
    engaged in extensive and detailed preplanning
    of the crimes. McKinney’s expert testified
    that persons with PTSD tended to avoid
    engaging in stressful situations, such as these
    burglaries and murders, which are likely to
    trigger symptoms of the syndrome. The judge
    observed that McKinney’s conduct in
    engaging in the crimes was counter to the
    behavior McKinney’s expert described as
    expected for people with PTSD. As we noted
    MCKINNEY V. RYAN                         45
    in discussing Hedlund’s claim on this same
    issue, a difficult family background, including
    childhood abuse, does not necessarily have
    substantial mitigating weight absent a
    showing that it significantly affected or
    impacted the defendant’s ability to perceive,
    comprehend, or control his actions. See State
    v. Ross, . . . 
    886 P.2d 1354
    , 1363 (1994)[.]
    Id. at 1234 (emphasis added).
    Based on (1) the factual conclusion by the sentencing
    judge, which the Arizona Supreme Court accepted, that
    McKinney’s PTSD did not “in any way affect[] his conduct
    in this case,” (2) the Arizona Supreme Court’s additional
    factual conclusion that, if anything, McKinney’s PTSD would
    have influenced him not to commit the crimes, and (3) the
    Arizona Supreme Court’s recital of the causal nexus test for
    nonstatutory mitigation and its pin citation to the precise page
    in Ross where it had previously articulated that test, we
    conclude that the Arizona Supreme Court held, as a matter of
    law, that McKinney’s PTSD was not a nonstatutory
    mitigating factor, and that it therefore gave it no weight. This
    holding was contrary to Eddings. We therefore hold that the
    decision of the Arizona Supreme Court applied a rule that
    was “contrary to . . . clearly established Federal law, as
    determined by the Supreme Court of the United States.”
    
    28 U.S.C. § 2254
    (d)(1).
    D. Structural or Harmless Error
    We have not heretofore decided whether an Eddings error
    is structural error. We do so now and conclude that it is not.
    46                   MCKINNEY V. RYAN
    The Supreme Court has consistently characterized
    structural errors as “structural defects in the constitution of
    the trial mechanism.” Brecht v. Abrahamson, 
    507 U.S. 619
    ,
    629 (1993). Because such errors go to the framework within
    which judicial proceedings are conducted, they “infect the
    entire trial process” and accordingly require “automatic
    reversal of the conviction.” 
    Id.
     at 629–30; see also Arizona
    v. Fulminante, 
    499 U.S. 279
    , 310 (1991) (noting that
    structural errors “affect[] the framework within which the
    trial proceeds”).       Some structural errors produce a
    fundamentally flawed record, so “any inquiry into [their]
    effect[s] on the outcome of the case would be purely
    speculative.” Satterwhite v. Texas, 
    486 U.S. 249
    , 256 (1988);
    see also Rose v. Clark, 
    478 U.S. 570
    , 579 & n.7 (1986)
    (holding that harmless-error analysis was appropriate because
    “[u]nlike errors such as judicial bias or denial of counsel, the
    error in this case did not affect the composition of the record.
    Evaluation of whether the error prejudiced respondent thus
    does not require any difficult inquiries concerning matters
    that might have been, but were not, placed in evidence”).
    By contrast, harmless-error analysis applies to trial errors,
    “which may . . . be quantitatively assessed in the context of
    other evidence presented in order to determine whether its
    admission was harmless.” Fulminante, 
    499 U.S. at
    307–08.
    Because “the error occurs at trial and its scope is readily
    identifiable[,] . . . the reviewing court can undertake with
    some confidence its relatively narrow task of assessing the
    likelihood that the error materially affected the deliberations
    of the jury.” Holloway v. Arkansas, 
    435 U.S. 475
    , 490
    (1978). For example, in Satterwhite, the Court applied
    harmless-error analysis to a Sixth Amendment error resulting
    in the improper admission of testimony from a psychiatrist
    who had examined Satterwhite without notifying his attorney.
    MCKINNEY V. RYAN                         47
    
    486 U.S. at 258
    . The Court noted that “the evaluation of the
    consequences of an error in the sentencing phase of a capital
    case may be more difficult because of the discretion that is
    given to the sentencer.” 
    Id.
     However, it held that the error at
    issue was subject to harmless-error analysis because the
    admission of testimony was an error of limited scope that was
    ready identifiable and whose impact could be assessed by a
    reviewing court. 
    Id.
     at 257–58.
    E. Harmless Error
    The harmless-error standard on habeas review provides
    that “relief must be granted” if the error “‘had substantial and
    injurious effect or influence in determining the jury’s
    verdict.’” Brecht, 
    507 U.S. at 623
     (quoting Kotteakos v.
    United States, 
    328 U.S. 750
    , 776 (1946)). “Under this
    standard, habeas petitioners may obtain plenary review of
    their constitutional claims, but they are not entitled to habeas
    relief based on trial error unless they can establish that it
    resulted in actual prejudice.” Id. at 637 (internal quotation
    marks omitted). But, as with the stricter Chapman standard,
    the “risk of doubt” is placed “on the State.” O’Neal v.
    McAninich, 
    513 U.S. 432
    , 439 (1995). On federal habeas, in
    the absence of structural error that requires automatic
    reversal, “relief is appropriate only if the prosecutor cannot
    demonstrate harmless error.” Ayala v. Davis, 
    135 S. Ct. 2187
    , 2197 (2015).
    The Court explained in Kotteakos,
    [I]f one cannot say, with fair assurance, after
    pondering all that happened without stripping
    the erroneous action from the whole, that the
    judgment was not substantially swayed by the
    48                  MCKINNEY V. RYAN
    error, it is impossible to conclude that
    substantial rights were not affected. The
    inquiry cannot be merely whether there was
    enough to support the result, apart from the
    phase affected by the error. It is rather, even
    so, whether the error itself had substantial
    influence. If so, or if one is left in grave
    doubt, the conviction cannot stand.
    
    328 U.S. at 765
    . Accordingly, “[w]hen a federal judge in a
    habeas proceeding is in grave doubt about whether a trial
    error of federal law had ‘substantial and injurious effect or
    influence in determining the jury’s verdict,’ that error is not
    harmless. And, the petitioner must win.” O’Neal, 
    513 U.S. at 436
    .
    We hold that the Eddings error committed by the Arizona
    Supreme Court in this case had a “substantial and injurious
    effect” on McKinney’s sentence within the meaning of
    Brecht. McKinney presented evidence of severe, prolonged
    childhood abuse that, in the words of the sentencing judge,
    was “beyond the comprehension and understanding of most
    people.” Dr. McMahon diagnosed McKinney as suffering
    from PTSD as a result of his horrific childhood. McKinney’s
    PTSD was important mitigating evidence, central to his plea
    for leniency, but the Arizona Supreme Court, as a matter of
    law, gave it no weight. See Coleman v. Calderon, 
    210 F.3d 1047
    , 1051 (9th Cir. 2000) (constitutionally infirm jury
    instruction was not harmless because “it undermined the very
    core of Coleman’s plea for life”). We hold here, as we did in
    Styers, that PTSD is mitigating evidence under Eddings.
    Styers, 
    547 F.3d at
    1035–36 (granting the writ based on
    Eddings error by the Arizona Supreme Court in treating
    PTSD mitigation evidence irrelevant as a matter of law). We
    MCKINNEY V. RYAN                         49
    hold, further, as we also did in Styers, that the Arizona
    Supreme Court’s refusal, as matter of law, to give weight to
    petitioner’s PTSD, requires resentencing. 
    Id.
    “[I]n capital cases the fundamental respect for humanity
    underlying the Eighth Amendment . . . requires consideration
    of the character and record of the individual offender and the
    circumstances of the particular offense as a constitutionally
    indispensable part of the process of inflicting the penalty of
    death.” Woodson v. North Carolina, 
    428 U.S. 280
    , 304
    (1976); see also Lockett, 
    438 U.S. at 605
     (“Given that the
    imposition of death by public authority is so profoundly
    different from all other penalties, we cannot avoid the
    conclusion that an individualized decision is essential in
    capital cases.”). When a defendant’s life is at stake, the
    Supreme Court has consistently emphasized the importance
    of a properly informed, individualized sentencing
    determination. See, e.g., Abdul-Kabir v. Quarterman,
    
    550 U.S. 233
    , 264 (2007) (noting that Lockett and its progeny
    “have made clear that when the jury is not permitted to give
    meaningful effect or a ‘reasoned moral response’ to a
    defendant’s mitigating evidence . . . the sentencing process is
    fatally flawed”); Satterwhite, 
    486 U.S. at 258
     (“It is important
    to avoid error in capital sentencing proceedings.”);
    McCleskey, 
    481 U.S. at 304
    ; Lockett, 
    438 U.S. at 604
     (“We
    are satisfied that this qualitative difference between death and
    other penalties calls for a greater degree of reliability when
    the death sentence is imposed.”).
    We recognize that there were important aggravating
    factors in this case. Although the jury had not found that
    McKinney had himself killed either Ms. Mertens or Mr.
    McClain, the sentencing judge concluded, based on
    substantial evidence, that McKinney had killed Ms. Mertens,
    50                   MCKINNEY V. RYAN
    though not Mr. McClain. Further, McKinney had been
    involved, as either the actual killer or as an accessory, in two
    murders; the murders had been done for pecuniary gain; and
    there had been cruelty to Mertens in the struggle preceding
    her death. We do not give “short shrift” to, or minimize the
    importance of, these aggravating factors. Bobby v. Van Hook,
    
    558 U.S. 4
    , 13 (2009) (per curiam). But we conclude that
    McKinney’s evidence of PTSD resulting from sustained,
    severe childhood abuse would have had a substantial impact
    on a capital sentencer who was permitted to evaluate and give
    appropriate weight to it as a nonstatutory mitigating factor.
    We conclude in this case that the Arizona Supreme Court’s
    application of its causal nexus test to exclude, as a matter or
    law, evidence of McKinney’s PTSD was “contrary to . . .
    clearly established Federal law, as determined by the
    Supreme Court of the United States,” and that its application
    of the test had a “substantial and injurious effect or influence”
    on its decision to sentence McKinney to death. Brecht,
    
    507 U.S. at 623
     (internal quotation marks omitted).
    VIII. Response to Dissent
    The foregoing opinion speaks for itself, but we add a few
    words to respond directly to two contentions in the dissent
    with which we particularly disagree.
    A. Consistent Articulation and Application of the Causal
    Nexus Test
    First, the dissent contends that during the relevant period
    the Arizona Supreme Court was inconsistent in its articulation
    and application of its unconstitutional causal nexus test for
    nonstatutory mitigation. We disagree. As we discuss in the
    body of our opinion, the Arizona Supreme Court, during a
    MCKINNEY V. RYAN                        51
    period of just over fifteen years, consistently insisted upon
    and applied its causal nexus test to nonstatutory mitigation.
    In no case during this period did the Court give any indication
    that the causal nexus test was not the law in Arizona, or any
    indication that it had the slightest doubt about the
    constitutionality of the test.
    The dissent particularly relies on four Arizona Supreme
    Court cases. Dissent at 89–96. Those cases are State v.
    Towery, 
    920 P.2d 290
     (Ariz. 1996), State v. Thornton,
    
    929 P.2d 676
     (Ariz. 1996), State v. Gonzales, 
    892 P.2d 838
    (Ariz. 1995), and State v. Trostle, 
    951 P.2d 869
     (Ariz. 1997).
    None of the four cases even remotely supports the dissent’s
    contention.
    Of the four cases, the dissent emphasizes Towery.
    Dissent at 89–90. In Towery, however, the Arizona Supreme
    Court clearly articulated and applied its causal nexus test.
    The defendant in Towery had introduced, as a would-be
    mitigating factor, evidence of his difficult family background.
    The sentencing judge “rejected the evidence as a mitigating
    factor because [Towery] failed to establish a nexus between
    his family background and his crime.” Towery, 
    920 P.2d at 310
    . The Arizona Supreme Court, on de novo review,
    affirmed the death sentence. It wrote:
    We have held that a difficult family
    background is not always entitled to great
    weight as a mitigating circumstance. State v.
    Wallace, . . . 
    773 P.2d 983
    , 985–86 (1989)
    (“A difficult family background is a relevant
    mitigating circumstance if a defendant can
    show that something in that background had
    an effect or impact on his behavior that was
    52                  MCKINNEY V. RYAN
    beyond the defendant’s control.”)[.] We have
    since reaffirmed that family background may
    be a substantial mitigating circumstance when
    it is shown to have some connection with the
    defendant’s offense-related conduct. White,
    . . . 
    815 P.2d at
    881–82.
    Defendant has failed to connect his family
    background to his criminal conduct.
    Id. at 311 (citations shortened). The Court in Towery could
    hardly have been clearer. It both articulated and applied its
    unconstitutional causal nexus test to treat as irrelevant, as a
    matter of law, nonstatutory mitigation evidence of the
    defendant’s family background because he had “failed to
    connect his family background to his criminal conduct.” Our
    three-judge panel decision, reviewing Towery’s conviction
    and sentence on federal habeas, held to the contrary, but it
    was mistaken in so holding. See Towery v. Ryan, 
    673 F.3d 933
     (9th Cir. 2012).
    The other three cases are of no greater help to the dissent.
    In Thornton, the sentencing judge had given mitigating
    weight to defendant’s “traumatic childhood, dysfunctional
    family, and antisocial personality disorder,” as it was
    permitted to do under Arizona law provided there was a
    causal nexus to the crime. The Arizona Supreme Court
    affirmed the judge on this point. It did not recite whether the
    judge had found a causal nexus; it simply affirmed without
    comment. The defendant contended that the sentencing judge
    should also have given weight to four other nonstatutory
    mitigating factors — mental illness, remorse, cooperation,
    and character. The Arizona Supreme Court rejected the
    contention that any of these factors were mitigating. It
    MCKINNEY V. RYAN                        53
    rejected three of them on the ground that they did not exist as
    a factual matter. It rejected the fourth with a citation to the
    precise page in Ross in which it had articulated its
    unconstitutional causal nexus test. In Gonzales, defendant
    contended his good character should have been given
    mitigating weight. The Arizona Supreme Court rejected the
    contention, holding as a factual matter that Gonzales did not
    have good character. In Trostle, the Arizona Supreme Court
    gave mitigating weight to the defendant’s mental impairment
    because the causal nexus test was satisfied. The Court wrote,
    [W]eight to be given to mental impairment
    should be proportional to a defendant’s ability
    to conform or appreciate the wrongfulness of
    his conduct.
    The defendant here established . . . that he
    was affected in no small measure by an
    impaired ability to conform his conduct to the
    law’s requirements. . . . The trial court,
    therefore, should have given serious
    consideration to this evidence, either as
    statutory or nonstatutory mitigation.
    951 P.2d at 886.
    The dissent also relies on two cases cited in Lopez v.
    Ryan, 
    630 F.3d 1198
    , 1204 n.4 (9th Cir. 2011) — State v.
    Mann, 
    934 P.2d 784
     (Ariz. 1997); and State v. Medrano,
    
    914 P.2d 225
     (Ariz. 1996). Neither case supports the
    dissent’s contention.
    In State v. Mann, the defendant had advanced four
    proposed nonstatutory mitigators: (1) the possibility of
    54                  MCKINNEY V. RYAN
    consecutive life sentences rather than the death penalty;
    (2) defendant’s relationship to his children; (3) a change in
    defendant’s “lifestyle” after he committed the murders; and
    (4) defendant’s difficult family background. 
    934 P.2d at 795
    .
    The Arizona Supreme Court held as a matter of law that the
    possibility of consecutive life sentences was “a sentencing
    option” rather than a mitigating factor. 
    Id.
     With respect to
    defendant’s relationship with his children and his change in
    lifestyle, the Court held that the defendant had not
    “established mitigation of sufficient weight to call for
    leniency.” 
    Id.
     Finally, the Court held that defendant’s
    difficult family background was irrelevant as a matter of law.
    It recited its causal nexus test, citing the precise page in its
    Wallace opinion on which it had articulated and applied the
    test. The Court then wrote, “Defendant did not show any
    connection.” 
    Id.
    In State v. Medrano, the defendant contended that his
    cocaine intoxication was both a statutory and nonstatutory
    mitigating factor. The sentencing judge had found as a
    factual matter that defendant’s cocaine intoxication had not
    affected his behavior in committing the crime. The Arizona
    Supreme Court applied the causal nexus test, writing that the
    sentencing judge had found that the defendant had “not
    proven by a preponderance of the evidence, either as a
    statutory or nonstatutory mitigating factor, that cocaine
    intoxication had contributed to his conduct on the night of the
    murder.” 
    914 P.2d at 227
    . The Arizona Supreme Court
    accepted the factual finding of the sentencing judge that there
    had been no causal nexus. The Court wrote that defendant’s
    evidence was “unpersuasive” and that his cocaine use
    therefore “fail[ed] as a non-statutory mitigating
    circumstance.” 
    Id. at 229
    .
    MCKINNEY V. RYAN                         55
    As we noted at the beginning of our opinion, the Arizona
    Supreme Court has a strong view of stare decisis. The Court
    wrote in White v. Bateman, 
    358 P.2d 712
    , 714 (Ariz. 1961),
    for example, that its prior case law “should be adhered to
    unless the reasons of the prior decisions have ceased to exist
    or the prior decision was clearly erroneous or manifestly
    wrong.” See also Young v. Beck, 
    251 P.3d 380
    , 385 (Ariz.
    2011) (“[S]tare decisis commands that ‘precedents of the
    court should not be lightly overruled,’ and mere disagreement
    with those who preceded us is not enough.” (quoting State v.
    Salazar, 
    173 Ariz. 399
    , 416 . . . (1992))); State ex re. Woods
    v. Cohen, 
    844 P.2d 1147
    , 1148 (Ariz. 1993) (referring to “a
    healthy respect for stare decisis”); State v. Williker, 
    491 P.2d 465
    , 468 (Ariz. 1971) (referring to “a proper respect for the
    theory of stare decisis”).
    Consistent with its view of stare decisis, the Arizona
    Supreme Court applied its unconstitutional causal nexus test
    consistently throughout during the relevant period. We
    would hardly expect the Court have done otherwise, given its
    view of stare decisis and the causal nexus test. The test was,
    of course, premised on a mistaken understanding of Eddings.
    The Court corrected its mistake, consistent with its view of
    stare decisis under Bateman (“the prior decision was clearly
    erroneous or manifestly wrong”), after the United States
    Supreme Court emphatically reiterated the Eddings rule in
    2004 in Tennard v. Dretke. See State v. Anderson, 
    111 P.3d 369
     (Ariz. 2005). But a mistake is only a mistake. All
    courts, even very good courts, make mistakes. A good court,
    however, does not apply an established rule erratically,
    enforcing it arbitrarily in some cases but not in others. We
    have great respect for the Supreme Court of Arizona, whose
    institutional integrity is demonstrated, inter alia, by the
    56                   MCKINNEY V. RYAN
    consistent application of the causal nexus test during the
    fifteen-year period it was in effect.
    B. Appellate Review and “Unreasonable Determination of
    Fact”
    Second, the dissent contends that the critical question
    before us is whether the Arizona Supreme Court properly
    concluded that the sentencing judge “fully considered
    McKinney’s PTSD.” Dissent at 82. It further contends that
    we must review whether the Court properly so concluded
    under the “unreasonable determination of fact” standard of
    AEDPA. 
    28 U.S.C. § 2254
    (d)(2). According to the dissent,
    the Arizona Supreme Court did not unreasonably make the
    factual determination that the sentencing judge had “fully
    considered McKinney’s PTSD.” Therefore, according to the
    dissent, we must uphold the sentencing decision of the
    Arizona Supreme Court. The dissent misunderstands both the
    significance of the Arizona Supreme Court’s de novo review
    in capital cases, and the “unreasonable determination of fact”
    standard of review under AEDPA.
    Contrary to the view of the dissent, the Arizona Supreme
    Court in reviewing capital sentences does not base its
    decision on whether the sentencing judge fully considered
    aggravating and mitigating factors. Rather, as we indicated
    above, the Arizona Supreme Court reviews capital sentences
    de novo, making its own independent determination of what
    constitute legally relevant aggravating and mitigating factors,
    and then performing an independent weighing of those
    factors. In its own words, the Arizona Supreme Court
    “conducts a thorough and independent review of the record
    and of the aggravating and mitigating evidence to determine
    whether the sentence is justified, . . . consider[ing] the quality
    MCKINNEY V. RYAN                        57
    and strength, not simply the number, of aggravating or
    mitigating factors.” McKinney, 
    917 P.2d at 1225
    .
    Further, and also contrary to the view of the dissent, the
    question whether the sentencing judge “fully considered
    McKinney’s PTSD” is not a question of “fact” under
    § 2254(d)(2). A “fact” under § 2254(d)(2) is an evidentiary
    fact, such as whether a defendant had PTSD or whether a
    defendant’s PTSD had a causal nexus to the crime. See, e.g.,
    Wood v. Allen, 
    558 U.S. 290
    , 850 (2010) (analyzing
    evidentiary facts under § 2254(d)(2)). Whether a sentencing
    judge fully considered an evidentiary fact is not a “fact”
    within the meaning of § 2254(d)(2).
    Conclusion
    We review the decision of the Arizona Supreme Court, as
    the last reasoned state court decision. The Arizona Supreme
    Court reviewed McKinney’s death sentence de novo. That
    Court accepted the factual conclusion of the trial judge that,
    as an evidentiary matter, there was no causal nexus between
    McKinney’s PTSD and his crimes. After accepting the
    conclusion of the trial judge on this factual point, the Court
    went further, noting that, far from contributing to his crimes,
    McKinney’s PTSD would have influenced him not to commit
    them. The Arizona Supreme Court then recited its
    unconstitutional causal nexus test for nonstatutory mitigation,
    followed by a pin citation to the page of Ross on which it had
    articulated that test two years earlier, making clear that, as
    matter of Arizona law, McKinney’s PTSD was not relevant
    as a nonstatutory mitigating factor.
    We reverse the district court’s judgment denying the writ
    of habeas corpus. We remand with instructions to grant the
    58                       MCKINNEY V. RYAN
    writ with respect to McKinney’s sentence unless the state,
    within a reasonable period, either corrects the constitutional
    error in his death sentence or vacates the sentence and
    imposes a lesser sentence consistent with law.
    BEA, Circuit Judge, dissenting, with whom KOZINSKI,
    GOULD, TALLMAN, and CALLAHAN, Circuit Judges,
    join:
    A state cannot impose the death penalty unless the
    sentencer has considered all evidence submitted as to the
    defendant’s condition, character, and background. Eddings v.
    Oklahoma, 
    455 U.S. 104
    , 113–15 (1982) (explaining that a
    sentencer may not “refuse to consider, as a matter of law, any
    relevant mitigating evidence”). As a result, defendants so
    sentenced usually and legitimately proffer mitigation
    evidence provoking sympathy in the hope it will persuade the
    sentencer to grant leniency and impose a life sentence instead
    of the death penalty. Here, James McKinney submitted
    evidence of his squalid, horrid childhood and expert
    testimony that, as a result of that childhood, he developed
    Post-Traumatic Stress Disorder (“PTSD”). He urged his
    PTSD called for mercy for two reasons. First, he argued his
    PTSD affected his mental capacity “to appreciate the
    wrongfulness of his conduct” at the time of the murders. This
    is a statutory mitigation factor under Arizona law.1 Second,
    he argued his childhood and childhood-caused PTSD justified
    leniency, separate from any effect it may have had on his
    mental state at the time of the murders. That second argument
    1
    
    Ariz. Rev. Stat. § 13-751
    (G)(1).
    MCKINNEY V. RYAN                               59
    fits under Arizona’s nonstatutory catchall that requires
    sentencers to consider all proffered mitigation evidence.2
    McKinney admits the sentencing judge, Judge Sheldon,
    considered his first argument. But McKinney contends Judge
    Sheldon did not consider the mitigating value of his PTSD for
    leniency purposes regardless its effect on him at the time of
    the murders.
    McKinney pressed this same claim before the Arizona
    Supreme Court on direct appeal from the sentence Judge
    Sheldon imposed. That court correctly stated what Eddings
    requires: “[T]he trial judge must consider any aspect of [a
    defendant’s] character or record and any circumstance of the
    offense relevant to determining whether a sentence less
    severe than the death penalty is appropriate.”3 It then rejected
    McKinney’s argument that Judge Sheldon had failed to
    consider his PTSD separate from its effect on McKinney’s
    mental capacity during the murders: “[T]he record shows that
    the judge gave full consideration to McKinney’s childhood
    and the expert testimony regarding the effects of that
    childhood, specifically the diagnosis of post-traumatic stress
    disorder.”4 That conclusion makes sense given Judge Sheldon
    expressly stated at McKinney’s sentencing:
    2
    
    Ariz. Rev. Stat. § 13-751
    (G) (“The trier of fact shall consider as
    mitigating circumstances any factors proffered by the defendant or the
    state that are relevant in determining whether to impose a sentence less
    than death, including any aspect of the defendant’s character, propensities
    or record and any of the circumstances of the offense.”).
    3
    State v. McKinney, 
    917 P.2d 1214
    , 1226 (Ariz. 1996).
    4
    
    Id. at 1234
     (emphasis added).
    60                       MCKINNEY V. RYAN
    I have considered [McKinney’s arguments] at
    length, and after considering all of the
    mitigating circumstances, the mitigating
    evidence that was presented by the defense in
    this case as against the aggravating
    circumstances, and other matters which
    clearly are not set forth in the statute which
    should be considered by a court, I have
    determined . . . that the mitigating
    circumstances simply are not sufficiently
    substantial to call for leniency under all of the
    facts of this case.
    (Emphasis added.)
    Our review of McKinney’s claim must proceed
    differently than it did in the Arizona courts on direct appeal.
    The Supreme Court has told us we must presume “state courts
    know and follow the law.”5 And, in the Eddings context,
    “[w]e must assume that the trial judge considered all [the]
    evidence before passing sentence.”6 This appeal could be
    resolved against McKinney, without the benefit of those
    presumptions, simply based on the above quotations from the
    record. This appeal presents even fewer problems to decide
    under the standard provided by the Antiterrorism and
    Effective Death Penalty Act of 1996 (“AEDPA”), which
    prescribes “‘a difficult to meet’ and ‘highly deferential
    standard for evaluating state-court rulings, [and] which
    demands state-court decisions be given the benefit of the
    5
    Woodford v. Visciotti, 
    537 U.S. 19
    , 24 (2002).
    6
    Parker v. Dugger, 
    498 U.S. 308
    , 314 (1991).
    MCKINNEY V. RYAN                               61
    doubt.’”7 Yet the majority still somehow concludes that,
    under the standard of review prescribed by AEDPA, there
    was Eddings error in this case.
    The majority starts by incorrectly summarizing the
    Arizona Supreme Court’s Eddings jurisprudence between
    1989 and 2005 as constituting continuous and recurrent
    Eddings error.8 Not so at all, as our own decisions have
    repeatedly recognized.9 Based on its incorrect summary of the
    Arizona decisions10 and a paean to stare decisis, the majority
    then rejects our precedent11 and concludes that we should
    never afford the Arizona Supreme Court the presumption that
    “state courts know and follow the law” with respect to any of
    7
    Cullen v. Pinholster, 
    131 S. Ct. 1388
    , 1398 (2011) (citation omitted).
    8
    Slip op. at 5–7, 26–38.
    9
    See Lopez v. Ryan, 
    630 F.3d 1198
    , 1203–04 (9th Cir. 2011) (“Some
    cases decided prior to Tennard applied a causal nexus requirement in an
    impermissible manner. Other cases, however, properly looked to causal
    nexus only as a factor in determining the weight or significance of
    mitigating evidence.”); Poyson v. Ryan, 
    743 F.3d 1185
    , 1198 (9th Cir.
    2013); Towery v. Ryan, 
    673 F.3d 933
    , 946 (9th Cir. 2012) (per curiam).
    10
    For a more accurate relation of the relevant Arizona Supreme Court
    cases, see infra Section III.B.1.
    11
    See Lopez, 
    630 F.3d at
    1203–04 (“In light of this backdrop, which
    highlights a range of treatment of the nexus issue, there is no reason to
    infer unconstitutional reasoning from judicial silence. Rather, we must
    look to what the record actually says.”); Clabourne v. Ryan, 
    745 F.3d 362
    ,
    372–73 (9th Cir. 2014), petition for rehearing and rehearing en banc
    pending, No. 09-99022 (9th Cir. Mar. 18, 2014); Poyson, 743 F.3d at 1198
    n.7; Schad v. Ryan, 
    671 F.3d 708
    , 723–24 (9th Cir. 2011); Greenway v.
    Schriro, 
    653 F.3d 790
    , 807–08 (9th Cir. 2011).
    62                        MCKINNEY V. RYAN
    that court’s Eddings cases.12 Rather, the majority creates a
    new and contrary presumption—that the Arizona courts did
    not know or follow Eddings between 1989 and 2005—and
    finds this presumption is not rebutted even where the Arizona
    courts have clearly complied with Eddings’s mandate.13 Of
    course, this process is quite contrary to the deferential
    standard of review the Supreme Court has told us to use.
    But the majority does not stop there. When the majority
    turns to the record in this case, it misreads it. The majority
    first suggests that when Judge Sheldon stated there was no
    evidence that McKinney’s PTSD “in any way affected his
    conduct in this case,” he applied an unconstitutional nexus
    test to exclude the PTSD from consideration altogether.14 Not
    so. At that portion of the hearing, Judge Sheldon was dealing
    with, and rejecting, McKinney’s own argument that his PTSD
    impaired his ability “to appreciate the wrongfulness of his
    conduct” at the time of the murders. Next, the majority states
    the Arizona Supreme Court “recited its unconstitutional
    causal nexus test” when it decided McKinney’s appeal.15 The
    court did no such thing; if it did state an unconstitutional
    nexus test, this case would be simple. Finally, the majority
    ignores the Arizona Supreme Court’s careful articulation of
    Eddings’s requirements and focuses instead on a single case
    12
    Slip op. at 7.
    13
    See 
    id.
    14
    
    Id.
     at 19–21, 42.
    15
    Id. at 21, 44–45, 57.
    MCKINNEY V. RYAN                         63
    citation in the Arizona opinion.16 None of this is permissible
    under AEDPA.
    In short, the majority ignores Supreme Court precedent,17
    implicitly overrules our own precedent,18 replaces AEDPA’s
    deferential standard of review of state-court decisions with an
    impermissible de novo standard, and misstates the record
    when applying that standard. Also quite troubling, the
    majority wrongly smears the Arizona Supreme Court and
    calls into question every single death sentence imposed in
    Arizona between 1989 and 2005 and our cases which have
    denied habeas relief as to those sentences. Finally, the
    majority brushes by the facts of McKinney’s gruesome
    crimes to find that the error the majority has manufactured
    was indeed prejudicial to the outcome of the sentencing,
    rather than harmless, in contravention of the prejudice
    standard stated in Brecht v. Abrahamson, 
    507 U.S. 619
    (1993).
    I respectfully dissent.
    I.
    This case should come down to a review of only a few
    pages of the transcript from McKinney’s sentencing, and a
    few pages from the Arizona Supreme Court’s decision
    16
    
    Id.
    17
    Visciotti, 
    537 U.S. at
    22–24; Parker, 
    498 U.S. at
    314–16.
    18
    See Clabourne, 745 F.3d at 372–73, petition for rehearing and
    rehearing en banc pending, No. 09-99022 (9th Cir. Mar. 18, 2014);
    Poyson, 743 F.3d at 1198 & n.7; Schad, 
    671 F.3d at
    723–24; Greenway,
    
    653 F.3d at
    807–08; Lopez, 
    630 F.3d at
    1203–04.
    64                      MCKINNEY V. RYAN
    affirming his sentence. State v. McKinney, 
    917 P.2d 1214
    ,
    1225–27, 1233–34 (Ariz. 1996). A brief discussion of the
    sentencing proceeding and Arizona’s statute governing the
    application of the death penalty may help analyze these few
    pages.
    A. The Statutory Scheme and McKinney’s Sentencing
    Arguments
    Arizona law separates mitigating evidence into two
    categories, statutory and nonstatutory. There are five statutory
    mitigating factors under Arizona’s sentencing statute: mental
    capacity, duress, minor participation, reasonable
    foreseeability, and age. 
    Ariz. Rev. Stat. § 13-751
    (G)(1)–(5).19
    The nonstatutory category is a catchall that requires the
    sentencer to consider “any factors proffered by the defendant
    or the state that are relevant in determining whether to impose
    a sentence less than death,” 
    id.
     § 13-751(G), “including any
    aspect of the defendant’s character or any circumstances of
    the offense relevant to determining whether a capital sentence
    is too severe.” State v. White, 
    982 P.2d 819
    , 824 (Ariz. 1999).
    McKinney’s sentencing memorandum included 11
    separate parts; each argued for leniency for different reasons.
    McKinney’s two primary arguments in support of leniency
    were based on his troubled childhood and his claimed
    resulting PTSD diagnosis. McKinney relied on his PTSD to
    make two arguments in support of leniency. First, in Part VIII
    of his sentencing memorandum, McKinney argued his PTSD
    19
    Arizona renumbered the statute in 2009, and it is now codified without
    any changes at 
    Ariz. Rev. Stat. § 13-751
    . See, e.g., Robinson v. Schriro,
    
    595 F.3d 1086
    , 1111 (9th Cir. 2010). This dissent cites to the new location
    of the statute.
    MCKINNEY V. RYAN                        65
    warranted leniency based on the statutory mitigation factor
    § 13-751(G)(1) (“Mental Capacity Factor”). The Mental
    Capacity Factor requires the court to consider whether “[t]he
    defendant’s capacity to appreciate the wrongfulness of his
    conduct or to conform his conduct to the requirements of law
    was significantly impaired, but not so impaired as to
    constitute a defense to prosecution.” 
    Ariz. Rev. Stat. § 13-751
    (G)(1). McKinney argued his PTSD diminished his
    capacity to appreciate the wrongfulness of his conduct during
    the murders of Christene Mertens and Jim McClain. It must
    be kept in mind that it was McKinney who claimed a causal
    nexus between his PTSD and his commission of the murders.
    So the sentencing judge can hardly be faulted for considering
    this as “nexus” evidence.
    Second, in Parts I and VII of his sentencing
    memorandum, McKinney argued his PTSD warranted
    leniency separate from any effect that PTSD may have had on
    him at the time of the murders. This argument did not assert
    McKinney’s PTSD played a role in the two murders. Thus, it
    did not fall under the statutory Mental Capacity Factor, or any
    other specific statutory mitigation factor. See 
    id.
     § 13-751(G)
    (duress, minor participation, reasonable foreseeability, and
    age). Instead, it fit under the nonstatutory catchall, quoted
    above.
    B. The PTSD Testimony
    McKinney called Diana McKinney, his sister, Susan
    Sesate, his aunt, and Dr. Mickey McMahon, a psychologist,
    to testify. The state called Dr. Steven Gray in rebuttal to Dr.
    McMahon’s testimony. McKinney’s sister and aunt testified
    to the conditions of McKinney’s squalid, harsh childhood. Dr.
    66                  MCKINNEY V. RYAN
    McMahon opined McKinney’s childhood caused McKinney
    to develop PTSD.
    Dr. McMahon testified that McKinney was a “loner” and
    not the type of criminal who would engage in “thrill-seeking
    behavior,” such as committing a crime for the sake of the
    excitement the crime provided. Instead, McKinney’s PTSD
    would lead him to avoid confrontations and stressful
    situations; and McKinney “tries to respond to [stress] by
    withdrawing.” Dr. McMahon agreed that McKinney would
    leave a stressful situation to avoid a confrontation if he could
    do so.
    Dr. McMahon testified there was a “high likelihood” that
    McKinney’s PTSD was triggered during his confrontation
    with his first victim, Christene Mertens, and McKinney’s
    mental capacity was diminished as a result. With respect to
    the McClain robbery and murder, Dr. McMahon admitted, “I
    don’t have enough facts to say that [McKinney] was suffering
    from diminished capacity.” Dr. McMahon testified that the
    murder of McClain in his sleep “would be the exact opposite
    of what I would expect from Mr. McKinney.” Those acts
    were consistent with someone who seeks out stressful
    situations rather than avoids them; it was a contra-indication
    to the presence of PTSD.
    The prosecution’s expert, Dr. Gray, did not diagnose
    McKinney with PTSD. He did not “think there’s enough
    evidence or diagnostic materials or work that’s been done to
    conclusively diagnose him as having [PTSD].” His tentative
    diagnosis was that McKinney has antisocial personality
    disorder. He explained that “[m]ost antisocial people have [a]
    major disturbance in thinking, not to be confused with
    schizophrenia or psychosis. They tend to, for example blame
    MCKINNEY V. RYAN                         67
    others for their situation.” Dr. Gray noted antisocial people
    typically avoid being a victim. Instead, “they want to be an
    offender, be in control, be in charge, be powerful even though
    the manner in which they do that is self-defeating, unhealthy
    and is abusive, harmful to others.” Which is why “people
    with antisocial personality have a long history of conflict with
    the law.”
    At the conclusion of the evidence, trial judge Sheldon
    credited defense expert Dr. McMahon’s testimony that
    McKinney had PTSD over Dr. Gray’s contrary opinion. He
    found that Dr. McMahon’s opinion was entitled “to more
    weight” than Dr. Gray’s testimony. He then adjourned for
    three days to consider the evidence before ruling on
    McKinney’s sentence.
    C. Judge Sheldon Considers McKinney’s PTSD Evidence
    Judge Sheldon imposed his sentence on July 23, 1993. At
    the outset of that hearing, he found the prosecution proved
    two aggravating factors for the Mertens murder: In the
    language of the statute, McKinney (1) “committed the offense
    as consideration for the receipt, or in expectation of the
    receipt, of anything of pecuniary value”; and (2) “committed
    the offense in an especially heinous, cruel or depraved
    manner.” See 
    Ariz. Rev. Stat. § 13-751
    (F)(5)–(6). No one
    disputes the solid footing in the record evidence for finding
    both of these aggravating factors. McKinney and Hedlund
    killed to get Mertens’s money. And before dispatching
    Mertens with a bullet to her head, McKinney and Hedlund
    savagely injured her. Judge Sheldon also found the
    government proved two aggravating factors for the murder of
    Jim McClain: (1) the pecuniary-gain aggravating factor; and
    (2) that McKinney was “convicted of another offense in the
    68                      MCKINNEY V. RYAN
    United States for which under Arizona law a sentence of life
    imprisonment or death was imposable,” i.e., the earlier
    Mertens murder. See 
    Ariz. Rev. Stat. § 13-751
    (F)(1), (5).
    Again, no one disputes the basis for these findings.
    McKinney and Hedlund killed McClain to get McClain’s
    money, and McKinney was convicted for the earlier murder
    of Mertens.
    Judge Sheldon then addressed McKinney’s mitigation
    evidence. Judge Sheldon started by crediting Dr. McMahon’s
    testimony twice and accepting Dr. McMahon’s PTSD
    diagnosis as true. Judge Sheldon then addressed McKinney’s
    nexus argument for leniency under the statutory Mental
    Capacity Factor, 
    id.
     § 13-751(G)(1), which McKinney had
    cited in his sentencing memorandum. Judge Sheldon stated
    there was no evidence McKinney’s PTSD “in any way
    significantly impaired Mr. McKinney’s conduct.” He
    repeated that conclusion a second time moments later, where
    he concluded there was no evidence that McKinney’s PTSD
    “in any way affected his conduct in this case.”20 Judge
    Sheldon reached that conclusion based on McKinney’s
    planning of the burglaries and statements McKinney made to
    witnesses before the burglaries that he would shoot a resident
    if he encountered one during the burglaries. Judge Sheldon
    noted Dr. McMahon testified that a person suffering from
    PTSD would be withdrawn and would “avoid contacts which
    would either exacerbate or recreate the trauma that would
    20
    Early in its opinion, the majority admits that this language is directed
    to McKinney’s argument for leniency under the statutory Mental Capacity
    Factor. Slip op. at 19. The majority nonetheless suggests these statements
    also show Judge Sheldon applied an unconstitutional nexus test. Id. at 20,
    42. As I discuss in detail below, at this point in the sentencing colloquy,
    Judge Sheldon is addressing the statutory mitigating factors and only the
    statutory mitigating factors. See infra Section III.A.2.
    MCKINNEY V. RYAN                           69
    bring on this type of stress from childhood.” But McKinney
    sought out stressful situations by planning and executing the
    burglaries that led to the two murders. Judge Sheldon
    concluded leniency was not available based upon the
    statutory Mental Capacity Factor, and repeated a third time
    his belief that the PTSD did not “significantly impair[]”
    McKinney’s conduct.
    This analysis of PTSD under the statutory mitigation
    factors did not end Judge Sheldon’s consideration of
    McKinney’s PTSD for purposes of mitigation. Judge Sheldon
    next transitioned to address “the other mitigating factors
    raised by the defense in their memorandum.”21 Those other
    mitigation factors included, among others, McKinney’s Part
    VII argument for leniency due to his difficult childhood and
    his psychological history, including his PTSD. After finding
    McKinney’s childhood did not support leniency, Judge
    Sheldon concluded: “With respect to the other matters set out
    in the [defendant’s sentencing] memorandum, I have
    considered them at length, and after considering all of the
    mitigating circumstances . . . I have determined that . . . the
    mitigating circumstances simply are not sufficiently
    substantial to call for a leniency under all of the facts of this
    case.” (Emphasis added.) The court then sentenced
    McKinney to death for both first-degree murder convictions.
    A week later, Judge Sheldon sentenced McKinney’s
    co-defendant, Michael Hedlund, to death.
    21
    This was the 27-page, 11-part sentencing memorandum, which Judge
    Sheldon specifically cited by date during his sentencing colloquy.
    70                   MCKINNEY V. RYAN
    D. McKinney’s Direct Appeal to the Arizona Supreme
    Court
    McKinney appealed his sentence. See McKinney,
    
    917 P.2d at
    1232–34. The Arizona Supreme Court addressed
    both McKinney’s and Hedlund’s sentences together in the
    same opinion, taking Hedlund’s first. As is common practice
    when a court addresses similar claims in the same opinion,
    the Arizona Supreme Court more fully articulated the legal
    standard applicable to both when it first addressed Hedlund’s
    arguments. 
    Id.
     at 1225–27. For Hedlund’s Eddings error
    argument, the court detailed what Eddings requires:
    Hedlund correctly observes that the trial judge
    must consider any aspect of his character or
    record and any circumstances of the offense
    relevant to determining whether a sentence
    less severe than death is appropriate. In
    considering such material, however, the judge
    has broad discretion to evaluate expert mental
    health evidence and to determine the weight
    and credibility given to it.
    
    Id. at 1226
    . The court then rejected Hedlund’s argument that
    Judge Sheldon failed to consider his mitigation evidence. 
    Id.
    at 1226–27.
    The court reached the same conclusion for McKinney’s
    Eddings argument: “Here again, the record shows that the
    judge gave full consideration to McKinney’s childhood and
    the expert testimony regarding the effects of that childhood,
    specifically the diagnosis of post-traumatic stress disorder.”
    
    Id. at 1234
    . The court concluded: “The record clearly shows
    that the judge considered McKinney’s abusive childhood and
    MCKINNEY V. RYAN                         71
    its impact on his behavior and ability to conform his conduct
    and found it insufficiently mitigating to call for leniency.” 
    Id.
    The court held Judge Sheldon did not err and affirmed
    McKinney’s sentence. 
    Id.
    II.
    A. What Eddings v. Oklahoma Requires and What It
    Prohibits
    Eddings’s command is simple. In Eddings, the trial judge
    stated that “in following the law” he could not “consider the
    fact of this young man’s violent background” in determining
    whether to sentence him to death. Eddings, 
    455 U.S. at
    112–13. The Supreme Court held the trial judge’s refusal to
    consider the evidence was unconstitutional under the Eighth
    Amendment. 
    Id.
     at 113–15. “Just as the State may not by
    statute preclude the sentencer from considering any
    mitigating factor, neither may the sentencer refuse to
    consider, as a matter of law, any relevant mitigating
    evidence.” 
    Id.
     at 113–14. Yet the Court made clear that the
    sentencer “may determine the weight to be given relevant
    mitigating evidence. But [it] may not give it no weight by
    excluding such evidence from [its] consideration.” 
    Id.
     at
    114–15. In later cases, the Supreme Court clarified that the
    sentencer cannot refuse to consider evidence because that
    evidence does not bear a causal nexus to the crime. See, e.g.,
    Tennard v. Dretke, 
    542 U.S. 274
    , 287 (2004). We have
    recognized that the sentencer may consider a “causal
    nexus . . . as a factor in determining the weight or
    significance of mitigating evidence.” Lopez v. Ryan, 
    630 F.3d 72
                           MCKINNEY V. RYAN
    1198, 1204 (9th Cir. 2011) (citing Eddings, 
    455 U.S. at
    114–15).22
    B. The “Last Reasoned Decision”
    AEDPA governs when we review a state’s determination
    whether a prisoner’s rights under the federal Constitution
    have been violated. See 
    28 U.S.C. § 2254
    . Under AEDPA,
    our review is confined to the “last reasoned decision” of the
    state courts. See Ylst v. Nunnemaker, 
    501 U.S. 797
    , 803–04
    (1991); Barker v. Fleming, 
    423 F.3d 1085
    , 1091 (9th Cir.
    2005). The “last reasoned decision” is the most recent
    “adjudication on the merits” that “finally resolve[s] the rights
    of the parties on the substance of the claim, rather than on the
    basis of a procedural or other rule precluding state review of
    the merits.” Barker, 
    423 F.3d at 1092
    .
    I agree with the majority that the Arizona Supreme
    Court’s opinion on direct review is the “last reasoned
    decision.” Slip op. at 41. I do not agree with the majority’s
    22
    A sentencer is free to assign whatever weight, including no weight,
    that mitigating evidence deserves under the facts of the case, as long as the
    sentencer does not exclude from his consideration relevant mitigating
    evidence as a matter of law. See, e.g., Towery, 673 F.3d at 945 (“One
    could question the wisdom of the Arizona Supreme Court’s decision to
    accord Towery’s evidence little or no weight. . . . However, the court’s
    reasoned and individualized decision to give Towery’s evidence little or
    no weight was not contrary to Supreme Court precedent.”); Allen v. Buss,
    
    558 F.3d 657
    , 667 (7th Cir. 2009) (“The rule of Eddings is that a
    sentencing court may not exclude relevant mitigating evidence. But of
    course, a court may choose to give mitigating evidence little or no
    weight.” (citation omitted)); United States v. Johnson, 
    495 F.3d 951
    , 965
    (8th Cir. 2007) (“[J]urors are obliged to consider relevant mitigating
    evidence, but are permitted to accord that evidence whatever weight they
    choose, including no weight at all.”).
    MCKINNEY V. RYAN                         73
    understanding of that opinion. The majority repeatedly refers
    to the Arizona Supreme Court’s review of McKinney’s
    sentence as a “de novo review.” See, e.g., id. at 4, 7, 9, 20, 41,
    43, 56–57. The Arizona Supreme Court does independently
    review each death sentence. See 
    Ariz. Rev. Stat. § 13-755
    .
    But the way it does its “independent review” is first to
    conduct a normal appellate review to determine whether the
    trial court made any legal errors when it imposed the death
    sentence. See 
    id.
     § 13-755(a)–(b). We owe this finding double
    deference under AEDPA. See, e.g., Lopez v. Schriro,
    
    491 F.3d 1029
    , 1037–38 & n.2 (9th Cir. 2007). After the
    Arizona Supreme Court reviews for legal errors, it then
    decides whether the death sentence is justified. See 
    Ariz. Rev. Stat. § 13-755
    (a)–(b); State v. Roseberry, 
    353 P.3d 847
    ,
    849–50 (Ariz. 2015) (“[T]his Court reviews the entire record
    and independently considers whether a capital sentence is not
    only legally correct, but also appropriate.”). Based on its own
    incorrect notion of what “independent review” means in
    Arizona practice, the majority converts this appellate review
    of death sentences into a new sentencing determination and
    treats McKinney’s trial-court sentencing hearing as irrelevant,
    except insofar as the Arizona Supreme Court accepted Judge
    Sheldon’s factual findings as its own. Slip op. at 21, 41–45.
    Although at times we construe an appellate court’s
    decision and a trial court’s decision together as the “last
    reasoned decision,” we do so only when the appellate court
    adopts the trial court’s decision. See, e.g., Barker, 
    423 F.3d at 1093
    . That is not what occurred here. The Arizona
    Supreme Court did not, as the majority posits, accept any of
    Judge Sheldon’s factual findings as its own. See slip op. at 21,
    41–45; McKinney, 
    917 P.2d at
    1233–34. The court merely
    reviewed McKinney’s argument that Judge Sheldon failed to
    consider McKinney’s mitigation evidence and concluded,
    74                     MCKINNEY V. RYAN
    “On this record there was no error.” McKinney, 
    917 P.2d at 1234
    . It also “independently reviewed the record,” as it was
    required to do under Arizona law, and affirmed McKinney’s
    death sentence. Id.; see also 
    id. at 1225
     (explaining the
    Arizona procedure for reviewing death sentences on direct
    appeal). For that reason, the Arizona Supreme Court’s
    opinion is the “last reasoned decision.” See Towery v. Ryan,
    
    673 F.3d 933
    , 944 n.3 (9th Cir. 2012) (per curiam) (refusing
    the petitioner’s suggestion to “review the decisions of the
    sentencing court and the [Arizona Supreme Court]
    together”).23
    C. AEDPA’s Deferential Review
    The standard by which federal courts must review
    state-court decisions under AEDPA is well known, if not
    always well followed. See 
    28 U.S.C. § 2254
    (d). Under
    § 2254(d)(1), a federal court can issue a writ of habeas corpus
    only if the state court’s decision “was contrary to, or involved
    an unreasonable application of, clearly established Federal
    law, as determined by the Supreme Court of the United
    States.” Id. § 2254(d)(1). Under § 2254(d)(2), a federal court
    can issue the writ only if the state court’s decision “was based
    on an unreasonable determination of the facts in light of the
    evidence presented in the State court proceeding.” Id.
    § 2254(d)(2).
    23
    The majority’s error in reviewing Judge Sheldon’s colloquy as part of
    the “last reasoned decision” makes no difference. To dispel any doubts,
    as I explain below, the record shows both the Arizona Supreme Court and
    Judge Sheldon complied with Eddings even under a de novo
    review—which is the wrong standard under AEDPA. See infra Section III.
    MCKINNEY V. RYAN                                75
    We apply the “contrary to” prong of § 2254(d)(1) where,
    as here, the parties dispute whether a state appellate court
    applied the correct standard. See Woodford v. Visciotti,
    
    537 U.S. 19
    , 22–24 (2002) (applying § 2254(d)(1) where the
    parties disputed whether the California Supreme Court
    applied the correct standard under Strickland). In this case, I
    apply § 2254(d)(1) when analyzing whether the Arizona
    Supreme Court used an unconstitutional nexus test in its
    review of McKinney’s sentence.
    The question whether a trial judge has considered all the
    proffered mitigation evidence is a factual question, not a legal
    one. See Lopez, 
    491 F.3d at
    1037–38 & n.2. And a state
    appellate court’s finding that the trial judge considered all the
    proffered mitigation evidence is itself a factual finding. See
    id.; see also Parker v. Dugger, 
    498 U.S. 308
    , 320 (1991). As
    a result, I apply § 2254(d)(2) to the Arizona Supreme Court’s
    finding that Judge Sheldon considered all of McKinney’s
    mitigation evidence, which can be overturned only if it was
    “unreasonable.” See Towery, 673 F.3d at 945 n.4; Lopez,
    
    491 F.3d at
    1037–38 & n.2. Judge Sheldon’s sentencing
    colloquy is relevant only for making that determination.24
    24
    The majority’s faulty understanding of the Arizona Supreme Court’s
    opinion leads it to conclude that I am wrong to apply § 2254(d)(2) in this
    case. Slip op. at 56–57. We previously used § 2254(d)(2) in habeas review
    of Arizona death sentences, see Towery, 673 F.3d at 945 n.4; Lopez,
    
    491 F.3d at
    1037–38 & n.2, as did Judge Wardlaw—who joins the
    majority opinion—in her partial dissent to the original panel opinion in
    this case, see McKinney v. Ryan, 
    730 F.3d 903
    , 925–27 (9th Cir. 2013)
    (Wardlaw, J., dissenting in part). The majority’s disagreement on this
    point creates a circuit split with at least two other circuits. See Corcoran
    v. Neal, 
    783 F.3d 676
    , 685–87 (7th Cir. 2015); Quince v. Crosby, 
    360 F.3d 1259
    , 1267 (11th Cir. 2004).
    76                       MCKINNEY V. RYAN
    III.
    I begin by evaluating McKinney’s appeal under the
    correct standard.25 That standard requires that we first
    determine whether the Arizona Supreme Court’s decision was
    “contrary to . . . clearly established Federal law” under
    § 2254(d)(1). Applied here, we must determine whether the
    Arizona Supreme Court treated McKinney’s PTSD as
    irrelevant to consider whether leniency was justified, because
    McKinney did not show the PTSD affected his conduct at the
    time of the murders. If the Arizona Supreme Court treated the
    PTSD as mitigation evidence relevant to whether leniency
    was justified, we must then determine whether the Arizona
    Supreme Court’s conclusion that Judge Sheldon fully
    considered McKinney’s PTSD was an “unreasonable
    determination of fact” under § 2254(d)(2).
    A. The Correct Analysis of the Arizona Supreme Court’s
    Decision
    1.
    This case primarily boils down to what standard the
    Arizona Supreme Court applied when addressing McKinney’s
    Eddings claim. “A decision is contrary to clearly established
    law if the state court ‘applies a rule that contradicts the
    governing law set forth in [Supreme Court] cases.’” Lafler v.
    Cooper, 
    132 S. Ct. 1376
    , 1390 (2012) (citation omitted);
    Frantz v. Hazey, 
    533 F.3d 724
    , 734 (9th Cir. 2008) (en banc)
    (“[U]se of the wrong legal rule or framework . . . constitute[s]
    error under the ‘contrary to’ prong of § 2254(d)(1).”). The
    25
    The majority’s incorrect standard is dealt with later. See infra Section
    III.B.
    MCKINNEY V. RYAN                             77
    state argues the Arizona Supreme Court correctly applied
    Eddings; McKinney argues the Arizona Supreme Court
    applied a “nexus” standard to exclude his PTSD from
    consideration contrary to Eddings.
    The Supreme Court’s decision in Visciotti governs our
    analysis under the “contrary to” prong of § 2254(d)(1). See
    Visciotti, 
    537 U.S. at
    22–24. In Visciotti, the petitioner argued
    the California Supreme Court applied the wrong standard for
    what constitutes prejudicial error under Strickland. 
    Id.
     To
    prove such prejudice under Strickland, “the defendant must
    establish a ‘reasonable probability that, but for counsel’s
    unprofessional errors, the result of the proceeding would have
    been different.’” 
    Id. at 22
     (quoting Strickland v. Washington,
    
    466 U.S. 668
    , 694 (1984)). In its opinion, the California
    Supreme Court began its Strickland analysis by twice stating
    the correct standard: “reasonable probability.” 
    Id.
     at 22–23.
    The opinion then misstated the “prejudice” standard four
    times in other portions of the opinion because it used the term
    “probable” instead of “reasonably probable.” Id. at 23.26
    Relying on the misstatements, we found the California
    Supreme Court applied the incorrect standard. Id. at 23–24.
    The decision was therefore “contrary to” Strickland under
    § 2254(d)(1). Id.
    In a per curiam opinion, and without the benefit of merits
    briefing or oral argument, the Supreme Court reversed our
    judgment. Id. at 22–24. The Court chided us for
    mischaracterizing the California Supreme Court’s decision,
    26
    Petitioner Visciotti made the point that the “reasonably probable”
    standard was an easier standard of proof for him to meet than the plain
    “probable.” Visciotti v. Woodford, 
    288 F.3d 1097
    , 1108–09 (9th Cir.
    2002).
    78                  MCKINNEY V. RYAN
    “which expressed and applied the proper standard for
    evaluating prejudice.” Id. at 22. Our “readiness to attribute
    error [was] inconsistent with the presumption that state courts
    know and follow the law.” Id. at 24 (citing Parker, 
    498 U.S. at
    314–16 (1991)). Our “readiness to attribute error” was
    “also incompatible with § 2254(d)’s ‘highly deferential
    standard for evaluating state-court rulings,’ which demands
    that state-court decisions be given the benefit of the doubt.”
    Id. (quoting Lindh v. Murphy, 
    521 U.S. 320
    , 333 n.7 (1997)).
    Visciotti’s teaching is not complicated. When we review
    a state-appellate-court decision under the “contrary to” prong
    of § 2254(d)(1), we must presume the state court knew and
    followed federal constitutional law. Id. And we must give the
    court the “benefit of the doubt.” Id. For that reason, we must
    construe any ambiguity in language in the state court’s favor.
    As applied to Eddings cases, when the state court identifies
    and articulates the correct Eddings standard, we must
    presume it applied that standard. That presumption can be
    rebutted by any action by the state court that shows the state
    court excluded the defendant’s mitigation evidence as a
    matter of law. The easiest way to rebut the presumption
    would be an express statement from the state court that it was
    excluding evidence from consideration as a matter of law,
    such as the trial judge’s statements in Eddings itself. See
    Eddings, 
    455 U.S. at
    112–13. However, that is not the only
    way to rebut the presumption. If the state court’s reasoning
    shows, without any ambiguity, that it did not consider
    relevant mitigation evidence at all, that would suffice to rebut
    the presumption. Any less deferential review rejects the
    presumption that Visciotti requires. This is the analysis that
    should replace our “clear indication” test for Eddings cases.
    See, e.g., Schad v. Ryan, 
    671 F.3d 708
    , 724 (9th Cir. 2011)
    (“Absent a clear indication in the record that the state court
    MCKINNEY V. RYAN                        79
    applied the wrong standard, we cannot assume the courts
    violated Eddings’s constitutional mandates.”).
    Applying Visciotti to this case is quick work. At no point
    did the Arizona Supreme Court state either that Judge
    Sheldon had excluded McKinney’s PTSD evidence as a
    matter of law, or that it would have been permissible to do so,
    under Arizona’s nonstatutory catchall because the PTSD bore
    no nexus to the crime. Nor did the Arizona Supreme Court
    treat that evidence as if it had no weight as a matter of law.
    That should be the end of the matter and of McKinney’s
    appeal. All the majority and McKinney do is speculate that,
    regardless what it stated, the Arizona Supreme Court applied
    a nexus test to conclude the PTSD evidence was irrelevant
    under the nonstatutory catchall. Visciotti prohibits such
    speculation.
    But let us make a closer inquiry anyway to quell any
    doubts raised by the majority’s flank attack on the Arizona
    Supreme Court’s decision. That court first outlined the
    Eddings standard when, in its combined review of Hedlund’s
    and McKinney’s sentences, it stated:
    Hedlund correctly observes that the trial judge
    must consider any aspect of his character or
    record and any circumstance of the offense
    relevant to determining whether a sentence
    less severe than the death penalty is
    appropriate. In considering such material,
    however, the judge has broad discretion to
    evaluate expert mental health evidence and to
    determine the weight and credibility given to
    it.
    80                  MCKINNEY V. RYAN
    McKinney, 
    917 P.2d at 1226
     (emphasis added). This is what
    Eddings requires and all that it requires. See Harris v.
    Alabama, 
    513 U.S. 504
    , 512 (1995) (“[T]he Constitution does
    not require a State to ascribe any specific weight to particular
    factors, either in aggravation or mitigation, to be considered
    by the sentencer.”). The Arizona Supreme Court then
    confirmed it knew the difference between excluding
    mitigation evidence altogether as a matter of law (Eddings
    error) and giving mitigation evidence little or no weight as a
    matter of fact (permissible under Eddings and Harris). See
    McKinney, 
    917 P.2d at 1231
     (noting that Judge Sheldon “did
    not improperly exclude mitigating evidence at sentencing and
    the mitigating evidence is not of great weight”).
    The Arizona Supreme Court then found Judge Sheldon
    complied with Eddings in McKinney’s case:
    Here again, the record shows that the
    judge gave full consideration to McKinney’s
    childhood and the expert testimony regarding
    the effects of that childhood, specifically the
    diagnosis of post-traumatic stress disorder
    (PTSD).
    
    Id. at 1234
     (emphasis added). The court continued:
    [A] difficult family background, including
    childhood abuse, does not necessarily have
    substantial mitigating weight absent a
    showing that it significantly affected or
    impacted the defendant’s ability to perceive,
    comprehend, or control his actions.
    MCKINNEY V. RYAN                         81
    
    Id.
     (emphasis added). In other words, when a difficult
    background does affect the “defendant’s ability to perceive,
    comprehend, or control his actions,” it has “substantial
    mitigating weight.” When there is no such effect, the
    evidence does not necessarily have substantial mitigating
    weight, but it can have such weight. That is up to the
    sentencer’s discretion.
    The best McKinney can do is point to the Arizona
    Supreme Court’s citation to State v. Ross, 
    886 P.2d 1354
    (Ariz. 1994), which is a case where that court did indeed
    misapply Eddings. But that single citation is insufficient to
    rebut the presumption that the court knew and followed
    Eddings. In Visciotti, the California Supreme Court misstated
    the Strickland prejudice standard four times after stating it
    correctly. Visciotti, 537 U.S. at 22–24. If actually misstating
    the standard four times is insufficient to rebut the
    presumption that the state court applied the correct standard
    (Visciotti), then the lesser sin of citing a suspect case cannot
    overcome the court’s correct statement of the law and the
    presumption it applied that law (McKinney). That is why we
    have previously held a single citation cannot be a basis for
    finding Eddings error on AEDPA review. See Towery,
    673 F.3d at 946. Indeed, a prior en banc panel of this court
    rejected this exact argument in the less deferential,
    pre-AEDPA context. See Jeffers v. Lewis, 
    38 F.3d 411
    , 415
    (9th Cir. 1994) (en banc). As a result, we must conclude the
    Arizona Supreme Court’s decision was not “contrary to . . .
    clearly established Federal law.”
    2.
    I turn to the Arizona Supreme Court’s conclusion that
    Judge Sheldon fully considered McKinney’s PTSD. That is
    82                   MCKINNEY V. RYAN
    a conclusion we review to determine whether it was an
    “unreasonable determination of fact” under § 2254(d)(2). See
    Lopez, 
    491 F.3d at
    1037–38 & n.2. We are barred from
    characterizing the Arizona Supreme Court’s “factual
    determination[] as unreasonable ‘merely because we would
    have reached a different conclusion in the first instance.’”
    Brumfield v. Cain, 
    135 S. Ct. 2269
    , 2277 (2015) (citation
    omitted). “Instead, § 2254(d)(2) requires that we accord the
    state . . . court substantial deference.” Id. “State-court factual
    findings . . . are presumed correct; the petitioner has the
    burden of rebutting the presumption by ‘clear and convincing
    evidence.’” Davis v. Ayala, 
    135 S. Ct. 2187
    , 2199–2200
    (2015) (citation omitted). If “‘reasonable minds reviewing the
    record might disagree’ about the finding in question, ‘on
    habeas review that does not suffice to supersede the [state
    court’s] determination.’” Brumfield, 
    135 S. Ct. at 2277
    (citation omitted).
    It requires no strenuous effort to conclude that Judge
    Sheldon fully considered McKinney’s PTSD. First, unlike the
    trial court judge in Eddings, at no point did Judge Sheldon
    state he was excluding the PTSD from consideration under
    the nonstatutory catchall as a matter of law because the PTSD
    had no effect on McKinney’s criminal conduct. Quite the
    opposite. Before sentencing McKinney, Judge Sheldon stated
    he “consider[ed] all of the mitigating circumstances.” That
    alone should preclude us from concluding the Arizona
    Supreme Court’s finding was an “unreasonable determination
    of fact.”
    But even were we to indulge in de novo review of the
    record, that review confirms that Judge Sheldon fully
    considered McKinney’s PTSD. Judge Sheldon’s discussion
    of McKinney’s mitigation arguments proceeded in three
    MCKINNEY V. RYAN                       83
    steps. First, at pages 26 to 28 of the sentencing transcript,
    Judge Sheldon discussed the mitigation evidence McKinney
    proffered, specifically citing McKinney’s sentencing
    memorandum by date. Second, at pages 28 to 31, Judge
    Sheldon addressed four statutory mitigating factors in 
    Ariz. Rev. Stat. § 13-751
    (G), including McKinney’s argument,
    under § 13-751(G)(1), that his PTSD affected his mental state
    at the time of the murders. Third, at pages 31 to 32, Judge
    Sheldon addressed the nonstatutory mitigating factors
    McKinney raised in his sentencing memorandum, including
    McKinney’s argument for leniency under the nonstatutory
    catchall due to his PTSD separate from its effect on his
    mental state at the time of the murders.
    That chronology proceeded as follows:
    •   At the conclusion of the evidentiary hearing, Judge
    Sheldon credited Dr. McMahon’s testimony: “I do
    believe that for purposes of this hearing that some
    evidence of [McKinney’s] possible manifestations of
    Post-traumatic Stress Syndrome were demonstrated
    by the testimony of Dr. McMahon. And I’ll just—I
    don’t know that I find it an overwhelmingly
    persuasive mitigating factor, but I will tell you that
    I’m, more inclined to believe that than Dr. Gray’s
    determination that there is not enough evidence to
    assume that there is Post-traumatic Stress Syndrome.”
    Judge Sheldon later stated Dr. McMahon’s PTSD
    diagnosis was entitled “to more weight under the
    circumstances of this case.”
    •   Judge Sheldon began his discussion of McKinney’s
    mitigation evidence at the sentencing hearing by
    stating, “I have considered all the exhibits admitted
    84                      MCKINNEY V. RYAN
    into evidence, Numbers 1 through 8.” At least one of
    those exhibits dealt with PTSD and its effects.27
    •   Judge Sheldon again credited defense witness Dr.
    McMahon’s testimony: “[I]t appears, and I believe
    that the statements made [about McKinney’s
    childhood], both by Dr. McMahon and made by the
    witnesses at the time they were testifying, were
    truthful, and I did take them into consideration in this
    case.” (Emphasis added.)
    •   Judge Sheldon then credited Dr. McMahon’s
    testimony that McKinney’s childhood led him to
    develop PTSD: “For whatever reasons, some of which
    I believe were due to the traumatic circumstances that
    he grew up in and the circumstances which were
    testified to by the witnesses during the mitigation
    hearing, the circumstances of child abuse, which I
    accept as true for purposes of this hearing, I think
    manifest the causal factors linked to Post-traumatic
    Stress Syndrome as testified to by Dr. McMahon.”
    After discussing an exhibit the defense proffered, Judge
    Sheldon turned to the statutory mitigation factors under 
    Ariz. Rev. Stat. § 13-751
    (G). He first addressed McKinney’s
    primary argument, contained in Part VIII of his sentencing
    memorandum, that McKinney was entitled to leniency under
    the statutory Mental Capacity Factor, § 13-751(G)(1) because
    his PTSD affected him at the time of the murders:
    27
    The exhibits are not in the parties’ excerpts of record, but they are
    discussed during the sentencing hearing.
    MCKINNEY V. RYAN                       85
    •   Judge Sheldon began: “[I]t appeared to me that Dr.
    McMahon did not at any time suggest in his
    testimony nor did I find any credible evidence to
    suggest that, even if the diagnosis of Post-traumatic
    Stress Syndrome were accurate in Mr. McKinney’s
    case, that in any way significantly impaired Mr.
    McKinney’s conduct.” Judge Sheldon repeated that
    conclusion a page later: “[A]nd it appeared to me that
    based upon all these circumstances that there simply
    was no substantial reason to believe that even if the
    trauma that Mr. McKinney had suffered in childhood
    had contributed to an appropriate diagnosis of
    Post-traumatic Stress Syndrome that it in any way
    affected his conduct in this case.”
    •   Judge Sheldon explained why he believed the PTSD
    did not affect McKinney’s state of mind at the time of
    the murders. Namely, McKinney’s pre-planning of
    the burglaries and homicides was inconsistent with
    Dr. McMahon’s testimony that PTSD would cause
    McKinney to avoid confrontation rather than seek it
    out.
    •   Judge Sheldon then concluded leniency was not
    available under the Mental Capacity Factor,
    § 13-751(G)(1), again repeating his belief that the
    PTSD did not “significantly impair[]” McKinney at
    the time of the murders.
    Judge Sheldon then addressed, and rejected, the other
    statutory mitigation factors.
    Finally, Judge Sheldon turned to McKinney’s
    nonstatutory mitigation factors. McKinney’s sentencing
    86                   MCKINNEY V. RYAN
    memorandum argued in two separate parts (Parts I and VII)
    that McKinney was entitled to leniency for his PTSD separate
    from any effect the PTSD had on his state of mind during the
    murders. Part I of the memorandum was titled: “Evidence of
    a Difficult Family History: Eddings v. Oklahoma, 
    supra.”
     In
    Part I, McKinney mentioned the childhood-caused PTSD as
    a mitigating factor along with his difficult childhood. The
    title’s citation to Eddings v. Oklahoma brought front and
    center the constitutional requirement that the PTSD diagnosis
    be considered without restriction. Part VII of the
    memorandum was titled: “Psychological History.” There,
    McKinney explained Dr. McMahon’s PTSD diagnosis and
    stated: “Defendant submits that his psychological background
    is mitigating.” Judge Sheldon made clear he considered both
    of these sections:
    •   Judge Sheldon started: “With respect to the other
    mitigating factors raised by the defense in their
    memorandum, defendant’s mitigating memorandum
    received by this Court July 15th, 1993, I have had an
    opportunity to review that memorandum.” Judge
    Sheldon then rejected the Part I argument that
    McKinney’s childhood warranted leniency.
    •   Judge Sheldon then addressed the remaining
    arguments McKinney made, which included Part
    VII’s argument that McKinney’s PTSD warranted
    leniency: “With respect to the other matters set out in
    the memorandum, I have considered them at length,
    and after considering all of the mitigating
    circumstances, the mitigating evidence that was
    presented by the defense in this case as against the
    aggravating circumstances, and other matters which
    clearly are not set forth in the statute which should be
    MCKINNEY V. RYAN                                87
    considered by the court, I have determined that . . .
    the mitigating circumstances simply are not
    sufficiently substantial to call for leniency under all of
    the facts of this case.” (Emphasis added.)28
    As the sentencing transcript shows, Judge Sheldon
    considered “at length” McKinney’s sentencing
    memorandum’s arguments that his PTSD diagnosis warranted
    leniency without any reference to PTSD’s possible effect on
    his mental capacity during the murders. And Judge Sheldon
    found the PTSD did not carry enough mitigating weight “to
    call for leniency.” When combined with Judge Sheldon’s
    prior crediting of Dr. McMahon’s testimony as to the PTSD
    diagnosis, the only conclusion to reach is that Judge Sheldon
    complied with Eddings. Even were there an ambiguity in
    Judge Sheldon’s statements (there isn’t), the Supreme Court
    has admonished that “[w]e must assume that the trial judge
    considered all this evidence before passing sentence. For one
    thing, he said he did.” Parker, 
    498 U.S. at 314
    .29
    28
    It was only in Part VIII of the sentencing memorandum that
    McKinney argued the causal relationship—“nexus”—between his PTSD
    and his criminal conduct.
    29
    Nor was McKinney entitled to a “specific listing and discussion of
    each piece of mitigating evidence under federal constitutional law.” See
    Jeffers, 
    38 F.3d at 418
     (“While ‘it is important that the record on appeal
    disclose to the reviewing court the considerations which motivated the
    death sentence,’ ‘due process does not require that the sentencer
    exhaustively document its analysis of each mitigating factor as long as a
    reviewing federal court can discern from the record that the state court did
    indeed consider all mitigating evidence offered by the defendant.’”
    (citation omitted) (quoting Gardner v. Florida, 
    430 U.S. 349
    , 361 (1977)
    (plurality opinion); Jeffries v. Blodgett, 
    5 F.3d 1180
    , 1197 (9th Cir.
    1993))).
    88                      MCKINNEY V. RYAN
    In short, the Arizona Supreme Court’s conclusion that
    Judge Sheldon properly considered all of McKinney’s
    mitigation evidence was not an “unreasonable determination
    of fact.” In fact, it was the correct conclusion.30
    B. The Majority’s Flawed Analysis
    Perhaps because the Arizona Supreme Court was explicit
    in its compliance with Eddings, the majority takes a very
    different course to conclude McKinney’s death sentence is
    invalid. The majority opinion proceeds in essentially two
    steps. First, it falsely paints the Arizona Supreme Court as a
    habitual violator of Eddings between 1989 and 2005. Based
    on that false assertion, the majority concludes the Visciotti
    presumption is automatically rebutted in this case and every
    other Eddings case coming out of Arizona within that time
    period. Slip op. at 7. In its place, the majority suggests the
    presumption is flipped and engages in a sort of de novo
    30
    McKinney also argues the Arizona Supreme Court and Judge Sheldon
    failed to consider his horrific childhood in violation of Eddings. The
    majority does not address that claim, but the record makes clear that Judge
    Sheldon considered that evidence too. He listened to lengthy testimony
    about it; he mentioned it several times in his colloquy; and he expressly
    stated: “I agree that there was evidence of a difficult family history by the
    defendant. However, as I’ve indicated, I do not find that is a substantial
    mitigating factor or that there was any evidence that linked that in any
    way to demonstrate that . . . somehow significantly impaired the
    defendant’s capacity to understand the wrongfulness of his conduct.”
    (Emphasis added.) Just like the PTSD evidence, Judge Sheldon considered
    McKinney’s childhood both as to its effect on McKinney at the time of the
    crimes and independently from any effect it may have had. The Arizona
    Supreme Court confirmed Judge Sheldon properly considered that
    evidence: “[T]he record shows that the judge gave full consideration to
    McKinney’s childhood and the expert testimony regarding the effects of
    that childhood.” McKinney, 917 P.2d at 1234.
    MCKINNEY V. RYAN                        89
    review to see if Arizona has rebutted the presumption it
    violated Eddings, with the burden of proof as to Eddings
    compliance on the Arizona courts. Id. at 41–45, 50–54.
    Second, the majority relies on a misreading of Judge
    Sheldon’s sentencing colloquy and the Arizona Supreme
    Court opinion to conclude the Arizona Supreme Court
    violated Eddings despite that court’s correct articulation of
    Eddings’s requirements. Id. I take each mistake in turn.
    1.
    The majority begins by acknowledging we are required to
    presume state courts know and follow the law. Id. at 7. But it
    concludes we should not afford the presumption in any
    Arizona Eddings case because the Arizona Supreme
    Court—like common-law courts generally—adheres to the
    principle of stare decisis and “applied its unconstitutional
    causal nexus test consistently throughout . . . the relevant
    period.” Id. at 6–7, 55–56. Though such a presumption is
    “appropriate in the great majority of habeas cases,” the
    majority posits, “the presumption is rebutted here where we
    know, based on its own words, that the Arizona Supreme
    Court did not ‘know and follow’ federal law.” Id. at 7. In
    other words, the majority relies on other Arizona Supreme
    Court cases to conclude the Arizona Supreme Court in this
    case is afforded no deference under AEDPA. Even if AEDPA
    permitted this type of analysis (it doesn’t, and the majority
    cites no case in support of it), the analysis is based on a false
    premise. The Arizona courts did not consistently misapply
    Eddings.
    The majority asserts that Arizona cases show a uniform
    error between 1989 and 2005. Id. at 26–38, 50–56. To see that
    assertion is wrong, one need look no further than a case the
    90                 MCKINNEY V. RYAN
    Arizona Supreme Court decided a mere six weeks after it
    decided McKinney’s appeal and squarely within that time
    period. See State v. Towery, 
    920 P.2d 290
     (Ariz. 1996).
    There, the court cited to Eddings and its progeny for the
    proposition that “[t]he sentencer . . . must consider the
    defendant’s upbringing if proffered but is not required to give
    it significant mitigating weight. How much weight should be
    given proffered mitigating factors is a matter within the sound
    discretion of the sentencing judge.” 
    Id. at 311
     (applying
    Penry v. Lynaugh, 
    492 U.S. 302
    , 319 (1989) (emphasis
    added)). The Arizona Supreme Court rejected defendant
    Towery’s argument that the trial judge failed to comply with
    Eddings when he considered Towery’s background and “gave
    it little or no mitigating value.” 
    Id.
     And, on habeas review of
    Towery, we concluded the Arizona Supreme Court complied
    with Eddings when it affirmed Towery’s sentence. Towery,
    673 F.3d at 944–46. In another case decided the same year as
    McKinney’s appeal, the Arizona Supreme Court found the
    defendant’s diagnosis of antisocial personality disorder to be
    a mitigating circumstance even though it did not find a nexus
    between that mental illness and the defendant’s crime. State
    v. Thornton, 
    929 P.2d 676
    , 685–86 (Ariz. 1996) (“We agree
    with the trial court that Thornton’s childhood, dysfunctional
    family, and personality disorder are mitigating factors.”).
    But Towery and Thornton are no outliers. A case decided
    a year before McKinney’s appeal was decided, see State v.
    Gonzales, 
    892 P.2d 838
    , 851 (Ariz. 1995) (applying Eddings),
    and a case decided a year after it, see State v. Trostle,
    
    951 P.2d 869
    , 885–86 (Ariz. 1997) (applying Lockett,
    Eddings’s precursor), confirm the Arizona Supreme Court
    knew how to apply Eddings correctly. Moreover, the Arizona
    Supreme Court relied on non-nexus mitigation evidence to
    vacate death sentences during the majority’s chosen time
    MCKINNEY V. RYAN                                91
    period, a fact our court has already recognized. See Lopez,
    
    630 F.3d at
    1203–04 (collecting cases for the proposition that
    “the Arizona Supreme Court expressly took mitigating
    evidence into consideration when reducing a death sentence
    to life, regardless of any causal nexus to the crime”
    (emphasis added)).
    Still, the majority would have us believe the Arizona
    Supreme Court usually applied an unconstitutional nexus test.
    It provides a long string citation in an attempt to prove its
    point. Slip op. at 32–34. But the Arizona Supreme Court did
    not even apply an invalid nexus test in many of the cases the
    majority cites. The majority cites two cases where we have
    already held on habeas review that the Arizona Supreme
    Court did not commit Eddings error.31 Indeed, as the majority
    recognizes, we have found there was no Eddings error in six
    additional cases during the relevant time period.32 
    Id.
     at
    38–39. The majority cites other cases where a federal district
    court has held there was no Eddings error and appeal is
    31
    See State v. Towery, 
    920 P.2d 290
    , 310–11 (Ariz. 1996), habeas relief
    denied in Towery, 673 F.3d at 944–47; State v. Stokley, 
    898 P.2d 454
    , 473
    (Ariz. 1995), habeas relief denied in part in Stokley v. Ryan, 
    705 F.3d 401
    ,
    404 (9th Cir. 2012) (explaining that “on balance, the Arizona Supreme
    Court’s opinion suggests that the court did weigh and consider all the
    evidence presented in mitigation at sentencing”).
    32
    Hedlund v. Ryan, 
    750 F.3d 793
    , 818 (9th Cir. 2014); Murray v.
    Schriro, 
    746 F.3d 418
    , 455 (9th Cir. 2014); Clabourne, 745 F.3d at
    371–74, petition for rehearing and rehearing en banc pending, No. 09-
    99022 (9th Cir. Mar. 18, 2014); Poyson, 743 F.3d at 1196–1200; Schad,
    
    671 F.3d at
    722–26; Lopez, 
    630 F.3d at
    1203–04.
    92                     MCKINNEY V. RYAN
    pending.33 
    Id.
     at 33–34. The majority also cites cases as
    examples of Eddings error where the Arizona Supreme Court
    gave little weight to mitigation evidence because there was no
    nexus between that evidence and the murder.34 Id. at 33. But
    giving little or no weight to such evidence as a factual matter
    is perfectly permissible under Eddings. See, e.g., Lopez, 
    630 F.3d at 1204
    . Finally, the two cases upon which the majority
    most heavily relies, State v. Djerf, 
    959 P.2d 1274
     (Ariz.
    1998), and State v. Hoskins, 
    14 P.3d 997
     (Ariz. 2000), came
    years after the Arizona Supreme Court affirmed McKinney’s
    sentence. See slip op. at 29–32.
    A close review of the majority’s string cite shows that, at
    worst, the Arizona Supreme Court sometimes misapplied
    Eddings in the years before that court affirmed McKinney’s
    sentence. See, e.g., Ross, 
    886 P.2d at 1363
    ; State v. Wallace,
    
    773 P.2d 983
    , 986 (Ariz. 1989). It is for that reason that we
    have always rejected the majority’s conclusion that the
    Arizona Supreme Court consistently applied an
    33
    See State v. Martinez, 
    999 P.2d 795
     (Ariz. 2000), habeas relief denied
    in Martinez v. Schriro, No. CV-05-1561-PHX-EHC, 
    2008 WL 783355
    , at
    *33 (D. Ariz. Mar. 20, 2008), appeal pending sub nom. Martinez v. Ryan,
    No. 08-99009 (9th Cir. May 29, 2008); State v. Rienhardt, 
    951 P.2d 454
    (Ariz. 1997), habeas relief denied in Rienhardt v. Ryan, 
    669 F. Supp. 2d 1038
    , 1059–60 (D. Ariz. 2009), appeal pending, No. 10-99000 (9th Cir.
    Jan. 8, 2010).
    34
    State v. Jones, 
    917 P.2d 200
    , 219 (Ariz. 1996) (“A difficult family
    background is not necessarily a mitigating circumstance unless defendant
    can show that something in his background had an effect on his behavior
    that was beyond his control.” (emphasis added)); State v. Bible, 
    858 P.2d 1152
    , 1209 (Ariz. 1993) (“In sum, our independent review of the record
    shows no significant mitigating evidence.” (emphasis added)).
    MCKINNEY V. RYAN                              93
    unconstitutional nexus test during this time period.35 As a
    result, we have always rejected the argument that the Arizona
    Supreme Court’s prior mistakes in this area are relevant to the
    decision before us.36 In fact, we have specifically rejected the
    argument that the Arizona Supreme Court is not entitled to
    the Visciotti presumption in Eddings cases. See Poyson v.
    Ryan, 
    743 F.3d 1185
    , 1198 (9th Cir. 2013). The majority
    today overrules these precedents sub silentio, and concludes
    Arizona is not entitled to the Visciotti presumption because
    Arizona has on occasion misapplied Eddings before.
    The majority’s response to the cases involving Eddings
    compliance reveals its view of the Arizona courts: No matter
    what the Arizona courts say, they never really considered all
    of the mitigation evidence. See slip op. at 50–56. For
    example, we previously held in Lopez that Arizona complied
    with Eddings during this time period and relied in part on
    three cases for that conclusion. See Lopez, 
    630 F.3d at
    1204
    n.4 (citing State v. Trostle, 
    951 P.2d 869
     (Ariz. 1997); State
    v. Mann, 
    934 P.2d 784
     (Ariz. 1997); State v. Medrano,
    
    914 P.2d 225
     (Ariz. 1996)). The majority gets around those
    cases by disregarding the parts of the cases that show the
    Arizona Supreme Court quite understood and applied
    35
    See Poyson, 743 F.3d at 1198; Towery, 673 F.3d at 946; Lopez,
    
    630 F.3d at
    1203–04.
    36
    See Poyson, 743 F.3d at 1198 n.7 (“We reject the suggestion that
    because other Arizona cases may have involved causal nexus error we
    should presume that this case did as well.”); see also Clabourne, 745 F.3d
    at 372–73, petition for rehearing and rehearing en banc pending, No. 09-
    99022 (9th Cir. Mar. 18, 2014); Schad, 
    671 F.3d at
    723–24 (finding the
    Arizona Supreme Court did not apply an unconstitutional nexus test in an
    opinion filed eight months after the court’s Wallace decision); Greenway,
    
    653 F.3d at
    807–08; Lopez, 
    630 F.3d at
    1203–04.
    94                      MCKINNEY V. RYAN
    Eddings’s mandate.37 Slip op. at 53–54. The majority
    37
    These cases show the Arizona Supreme Court understood that Eddings
    requires consideration of non-nexus mitigation evidence but that the
    sentencing court retains discretion over how much weight, if any, to afford
    such evidence. In Trostle, the Arizona Supreme Court explicitly discussed
    Eddings’s mandate and concluded, “In considering evidence of mental
    impairment, our primary task is to determine its mitigating weight, if any.”
    951 P.2d at 885–86. The court expressly considered numerous pieces of
    non-nexus mitigating evidence: Trostle’s cooperation with the police, past
    drug and alcohol abuse, good conduct during trial, loving family
    relationships, ability to function well in a structured environment, lack of
    a prior felony conviction, and remorse. Id. at 887. The Arizona Supreme
    Court noted that the trial court should have considered such evidence and
    factored the evidence into its independent reweighing of the aggravating
    and mitigating factors. Id. at 887–88. The court reduced Trostle’s death
    sentence to life imprisonment. Id. at 888.
    In Mann, the Arizona Supreme Court reviewed four pieces of non-
    nexus mitigating evidence and found Mann did not “establish[] mitigation
    of sufficient weight to call for leniency.” 
    934 P.2d at 795
    . The majority
    concedes that the Arizona Supreme Court considered, but gave little
    weight to, two pieces of non-nexus mitigating evidence: Mann’s
    relationship with his children and a change in Mann’s lifestyle post-dating
    his crimes. Slip op. at 53–54. The majority contends, however, that the
    court “held that defendant’s difficult family background was irrelevant as
    a matter of law.” Id. at 54. The Arizona Supreme Court did no such thing.
    It stated “[a]n abusive family background is usually given significant
    weight as a mitigating factor only when the abuse affected the defendant’s
    behavior at the time of the crime.” Mann, 
    934 P.2d at 795
     (emphasis
    added). This statement is entirely consistent with Eddings: It shows the
    court understood it could ascribe Mann’s family background the
    mitigating weight it deserves. Cf. supra Section III.A.1. The majority also
    contends Mann’s citation to Wallace shows the Arizona Supreme Court
    applied an unconstitutional causal-nexus test to Mann’s evidence of a
    troubled family background. Slip op. at 54. However, the court also cited
    a case in which it did not ascribe “much weight” to the defendant’s
    “difficult family background,” which is entirely consistent with Eddings.
    See Mann, 
    934 P.2d at
    795 (citing State v. West, 
    862 P.2d 192
    , 211–12
    MCKINNEY V. RYAN                                  95
    similarly gives short shrift to State v. Thornton, 
    929 P.2d 676
    (Ariz. 1996), and State v. Gonzales, 
    892 P.2d 838
     (Ariz.
    1995).38 Slip op. at 52–53.
    The majority is grasping at straws. First, the majority has
    flipped the presumption to require us to presume the Arizona
    courts violated Eddings. No law or case is cited for this
    proposition. Second, those cases demonstrate compliance
    (Ariz. 1993), overruled on other grounds by State v. Rodriguez, 
    961 P.2d 1006
     (Ariz. 1998)).
    In Medrano, the Arizona Supreme Court reviewed Medrano’s cocaine
    use both as a statutory mitigating factor and as a nonstatutory mitigating
    factor. 
    914 P.2d at
    227–29. The court found Medrano’s cocaine use did
    not qualify as a statutory mitigating factor under 
    Ariz. Rev. Stat. § 13
    -
    751(G)(1) because Medrano failed to prove his cocaine use significantly
    impaired his ability to conform his conduct to the law or appreciate the
    wrongfulness of his actions. Id. at 228. The Arizona Supreme Court
    acknowledged it was required to consider Medrano’s cocaine use
    regardless any causal connection, but found Medrano’s cocaine use
    unpersuasive as mitigating evidence. Id. at 229 (citing State v. Ramirez,
    
    871 P.2d 237
    , 252 (Ariz. 1994) (“[A]lthough [courts] must consider all
    evidence offered in mitigation, they are not bound to accept such evidence
    as mitigating.” (alterations in original))). The court then noted that the trial
    court, consistent with Eddings, rejected Medrano’s “claim that cocaine
    intoxication, under these facts, is sufficiently mitigating to call for
    leniency.” Id.; see also 
    id.
     (“Judges are presumed to know and follow the
    law and to consider all relevant sentencing information before them.”).
    38
    The majority takes issue with Thornton’s citation to Ross, slip op. at
    53, but ignores that the citation to Ross is for a point that is irrelevant to
    the majority’s analysis. See Thornton, 
    929 P.2d at 686
     (“Thornton argues
    that his cooperation with law enforcement is a mitigating factor.
    Thornton’s admission of guilt after he was stopped and his offer to admit
    guilt in exchange for the state withdrawing the request for the death
    penalty furthered his own interest. Cooperation that is in the best interest
    of the accused is not a mitigating circumstance. State v. Ross . . . .”).
    96                   MCKINNEY V. RYAN
    with Eddings sufficient to rebut this newly created flipped
    presumption. Look at Gonzales. There, the Arizona Supreme
    Court explained that “[i]n capital sentencing proceedings, the
    trial court must consider the mitigating factors in [Ariz. Rev.
    Stat.] § 13-703(G) as well as any aspect of the defendant’s
    background or the offense relevant to determining whether
    the death penalty is appropriate.” Gonzales, 
    892 P.2d at 850
    (emphasis added). The court later noted:
    From the detailed special verdict, it is
    clear that the trial court considered all
    evidence offered in mitigation. He was
    required to do no more. See Eddings v.
    Oklahoma, 
    455 U.S. 104
    , 112 (1982)
    (applying the rule in Lockett v. Ohio that the
    “sentencer in capital punishment cases must
    be permitted to consider any relevant
    mitigating factor”).
    Id. at 851. Does that not show the Arizona Supreme Court
    here complied with Eddings? What else could the court have
    done to overcome the majority’s flipped presumption?
    In short, the majority’s response to those cases showing
    compliance with Eddings is nothing short of an act of
    contortion. See slip op. at 50–56. It cannot escape the fact that
    the Arizona Supreme Court applied Eddings correctly during
    the relevant time period. As a result, there is no reason to
    invert the presumption that the Arizona courts knew and
    followed the law into a presumption they did not.
    MCKINNEY V. RYAN                        97
    2.
    After freeing itself from the presumption that state courts
    know and follow the law, the majority engages in de novo
    review and concludes the Arizona courts here applied an
    unconstitutional nexus test. Id. at 41–45. As I have shown,
    even a de novo review shows there was no Eddings error. The
    majority reaches the opposite conclusion largely by
    selectively reading—better said, misreading—the record.
    To start, the majority states that the Arizona Supreme
    Court accepted Judge Sheldon’s conclusions, at pages 28 and
    29 of the sentencing transcript, that McKinney’s PTSD did
    not affect his state of mind at the time of the murders and, in
    any event, would have influenced him not to commit the
    murders. Id. at 41–45. The majority suggests this part of the
    sentencing colloquy “echoes” the Arizona Supreme Court’s
    nexus test and implies these statements show the court
    applied a nexus test to exclude McKinney’s PTSD evidence
    from consideration under the nonstatutory mitigation factor.
    Id. at 19–22, 41–45. But the majority admits these statements
    are directed to Judge Sheldon’s analysis of the statutory
    mitigating factors, which, as I have explained, is the correct
    understanding. Id. at 19–20. So, even if the Arizona Supreme
    Court accepted Judge Sheldon’s conclusion that there was no
    causal connection between McKinney’s PTSD and the
    murders, there was no error.
    Moreover, the majority’s analysis rests on an assumption
    that the Arizona Supreme Court accepted a single factual
    finding by Judge Sheldon and ignored the rest of Judge
    Sheldon’s sentencing colloquy. As I have already explained,
    the Arizona Supreme Court did not rely on any of Judge
    98                       MCKINNEY V. RYAN
    Sheldon’s factual conclusions.39 But if the Arizona Supreme
    Court did accept any of Judge Sheldon’s findings regarding
    McKinney’s mitigation evidence, it accepted all of them. See
    McKinney, 
    917 P.2d at 1234
     (“[T]he record shows that the
    judge gave full consideration to McKinney’s childhood and
    the expert testimony regarding the effects of that childhood,
    specifically the diagnosis of post-traumatic stress disorder.”
    (emphasis added)); 
    id.
     (“The record clearly shows that the
    judge considered McKinney’s abusive childhood and its
    impact on his behavior and ability to conform his conduct.”
    (emphasis added)).40 The majority’s selective reading of
    39
    The Arizona Supreme Court merely reviewed whether Judge Sheldon
    considered all of McKinney’s mitigation evidence, found “[t]he record
    clearly shows that the judge considered McKinney’s” mitigation evidence,
    and concluded, “On this record there was no error.” McKinney, 917 P.2d
    at 1234. It did not accept Judge Sheldon’s factual findings as part of its
    own review of McKinney’s sentence.
    40
    During Hedlund’s sentencing colloquy, Judge Sheldon specifically
    cited to Eddings and Lockett v. Ohio, 
    438 U.S. 586
     (1978), and explained
    those cases required him to “weigh carefully, fairly, objectively, all of the
    evidence offered at sentencing, recognizing that not everyone who
    commits murder should be put to death.” Hedlund v. Ryan, 
    750 F.3d 793
    ,
    816 (9th Cir. 2014). Judge Sheldon then considered Hedlund’s alcohol
    abuse: “The Court has concluded that although evidence of alcohol use [is
    not] a mitigating circumstance under (G)(1), [it] nevertheless should be
    considered as mitigating evidence.” (Emphasis added.) Judge Sheldon
    later reiterated that point: “The defendant’s dependent personality traits,
    his past drug and alcohol abuse, and child abuse have been considered by
    the Court. If not demonstrating the existence of the mitigating factors
    under (G)(1), they have nevertheless been given consideration by the
    Court.” (Emphasis added.) He then concluded with a discussion of
    Hedlund’s childhood evidence: “I have considered [that evidence]. I think
    it is the court’s obligation to consider, whether or not it complies with the
    requirements in (G)(1).” (Emphasis added.) The majority fails to explain
    why the Arizona Supreme Court ignored this discussion even though the
    MCKINNEY V. RYAN                          99
    Judge Sheldon’s analysis is therefore wrong on multiple
    levels. It is also irrelevant to the outcome of the case. That the
    Arizona Supreme Court may have accepted Judge Sheldon’s
    conclusion that the evidence showed McKinney’s PTSD did
    not affect his conduct does not show Eddings error. To
    violate Eddings the court must have excluded the evidence
    from consideration altogether because of the lack of a nexus.
    The rest of the majority’s evaluation of the Arizona
    Supreme Court’s decision is just as flawed. The majority first
    asserts, citing Djerf for support, that the Arizona Supreme
    Court did not really consider McKinney’s PTSD evidence
    even though it used the word “considering.” Slip op. at
    43–43. That is nonsense. The referenced case, Djerf, came
    two years after McKinney’s appeal. See Djerf, 
    959 P.2d at 1274
    . It is irrelevant to the Arizona Supreme Court’s decision
    in this case.
    Next, the majority conclusorily asserts that the Arizona
    Supreme Court “recited its unconstitutional causal nexus
    test.” Slip op. at 21, 44, 57. It did? If the Arizona Supreme
    Court recited a causal-nexus test, then why would the
    majority need so many pages to reach the conclusion that the
    court did, in fact, apply a causal-nexus test? It appears the
    majority believes the following to be an unconstitutional
    nexus test:
    [A] difficult family background, including
    childhood abuse, does not necessarily have
    substantial mitigating weight absent a
    showing that it significantly affected or
    court reviewed Hedlund’s and McKinney’s death sentences in the same
    opinion.
    100                   MCKINNEY V. RYAN
    impacted the defendant’s ability to perceive,
    comprehend, or control his actions.
    McKinney, 
    917 P.2d at 1234
     (emphasis added). Not so. As I
    have noted, this statement means that when a difficult
    background does affect the “defendant’s ability to perceive,
    comprehend, or control his actions,” it has “substantial
    mitigating weight.” But when there is no such effect, the
    evidence does not necessarily have substantial mitigating
    weight, but it can have such weight. For that reason, I am at
    a loss to understand the majority’s conclusion that the
    Arizona Supreme Court recited an unconstitutional nexus test.
    Finally, the majority relies on the Arizona Supreme
    Court’s citation to Ross. See slip op. at 42–45; Ross, 
    886 P.2d at 1363
    . Visciotti forecloses any reliance on the citation to
    Ross to find Eddings error.41 But even if we looked at the
    Arizona Supreme Court’s citation to Ross without the
    Visciotti presumption, we should conclude that court applied
    Eddings correctly. The court correctly stated Eddings’s
    requirements several times. See McKinney, 
    917 P.2d at
    1226–27, 1234. The majority’s reliance on that citation,
    rather than the words the Arizona Supreme Court actually
    used, demonstrates the majority is applying the flipped
    41
    To that end, the majority implicitly overrules our prior en banc
    decision where we held a citation to a suspect case does not show the
    Arizona court misapplied Eddings. See Jeffers, 
    38 F.3d at 415
    .
    MCKINNEY V. RYAN                               101
    presumption it references elsewhere in its opinion.42 See slip
    op. at 7, 50–56.
    In short, none of the reasons the majority relies on support
    its conclusion that the Arizona Supreme Court misapplied
    Eddings.
    IV. The Harmless-Error Analysis
    The majority’s final mistake comes in its harmless-error
    analysis.43 Habeas petitioners “are not entitled to habeas relief
    42
    The majority claims that a single citation to Ross in the Arizona
    Supreme Court’s opinion renders the court’s treatment of McKinney’s
    mitigating evidence suspect. Slip op. at 42–45. By that logic, a citation to
    Eddings, Lockett, Eddings’s precursor, or State v. McMurtrey, 
    664 P.2d 637
     (Ariz. 1983), an Arizona Supreme Court case the majority
    acknowledges applies Eddings correctly, should demonstrate compliance
    with Eddings. See, e.g., State v. Canez, 
    42 P.3d 564
    , 593 (Ariz. 2002)
    (citing Lockett and McMurtrey); State v. Sharp, 
    973 P.2d 1171
    , 1183
    (Ariz. 1999) (citing Lockett); Trostle, 
    951 P.2d at
    885–86 (citing Lockett
    and McMurtrey); Towery, 
    920 P.2d at
    311 n.2 (citing Eddings and
    Lockett); Gonzales, 
    892 P.2d at
    851 (citing Eddings, Lockett, and
    McMurtrey); Bible, 
    858 P.2d at
    1209 (citing McMurtrey); State v. Brewer,
    
    826 P.2d 783
    , 802 (Ariz. 1992) (citing McMurtrey); State v. White,
    
    815 P.2d 869
    , 889 (Ariz. 1991) (citing Lockett); State v. Walton, 
    769 P.2d 1017
    , 1034 (Ariz. 1989) (citing Lockett).
    43
    I agree that Eddings error is not structural and is instead subject to
    harmless-error analysis, as we have already recognized. Henry v. Ryan,
    
    720 F.3d 1073
    , 1089 (9th Cir. 2013). Indeed, most circuits have held
    Eddings error is not structural. See Campbell v. Bradshaw, 
    674 F.3d 578
    ,
    596 (6th Cir. 2012); McGehee v. Norris, 
    588 F.3d 1185
    , 1197 (8th Cir.
    2009); Ferguson v. Sec’y of Dep’t of Corr., 
    580 F.3d 1183
    , 1201 (11th
    Cir. 2009); Martini v. Hendricks, 
    348 F.3d 360
    , 371 (3d Cir. 2003);
    Bryson v. Ward, 
    187 F.3d 1193
    , 1205–06 (10th Cir. 1999); Boyd v.
    French, 
    147 F.3d 319
    , 327–28 (4th Cir. 1998); Williams v. Chrans,
    
    945 F.2d 926
    , 949 (7th Cir. 1991). But see Nelson v. Quarterman,
    102                    MCKINNEY V. RYAN
    based on trial error unless they can establish that it resulted in
    ‘actual prejudice.’” Brecht, 
    507 U.S. at 637
     (citation omitted).
    We can grant habeas relief only if we have “grave doubt
    about whether a trial error of federal law had ‘substantial and
    injurious effect or influence in determining the [sentencer’s]
    verdict.’” O’Neal v. McAninch, 
    513 U.S. 432
    , 436 (1995)
    (citation omitted). There must be more than a “reasonable
    possibility” that an error was harmful. Brecht, 
    507 U.S. at 637
    . Anything less puts the state to the “arduous task [of
    retrying a defendant] based on mere speculation that the
    defendant was prejudiced by trial error.” Calderon v.
    Coleman, 
    525 U.S. 141
    , 146 (1998) (per curiam). Here,
    would lack of consideration of McKinney’s PTSD cause us
    to have “grave doubt” that Judge Sheldon would have
    imposed the death sentence? No.
    Judge Sheldon found the prosecution established four
    aggravating factors, two as to each of the murders. See 
    Ariz. Rev. Stat. § 13-751
    (F)(1), (5)–(6). First, Judge Sheldon found
    McKinney committed not one, but two murders, i.e., the
    murders of Mertens and McClain. Second, he found Mertens
    was murdered “in an especially heinous, cruel or depraved
    manner.” For that finding, Judge Sheldon credited testimony
    that McKinney admitted to his father that he shot Mertens.
    Judge Sheldon then explained the evidence at trial “showed
    that [Mertens] struggled violently to survive before being
    killed by a shot to the head.” There were numerous “non-fatal
    wounds” and a “substantial amount of blood over large areas
    of [Mertens’s] body, and the house, the bottom of her shoes,
    her slippers, which suggests that a struggle occurred while
    she was conscious.” He concluded it was reasonable to
    
    472 F.3d 287
    , 314 (5th Cir. 2006) (en banc) (finding Eddings error to be
    structural).
    MCKINNEY V. RYAN                       103
    assume Mertens “suffered tremendous physical torment prior
    to her death.” The murder was therefore “cruel.” At the very
    least, Judge Sheldon found the “violence was gratuitous” and
    “clearly” unnecessary, which supported a finding that
    McKinney’s state of mind was “heinous and depraved.”
    Finally, Judge Sheldon found McKinney committed both
    murders with the expectation that they would lead to
    pecuniary gain. The Arizona Supreme Court did not disturb
    any of these findings on direct appeal. McKinney, 917 P.2d at
    1233–34.
    The majority opinion treats these aggravating factors as
    an afterthought. See slip op. at 49–50. It daintily elides a
    description of the facts by which the murders were
    committed. Yet the majority claims to have conducted a
    harmless-error analysis without giving the aggravating factors
    “short shrift.” See id. Properly considered, these factors show
    the alleged failure to consider McKinney’s PTSD, had it
    occurred, would have been harmless. As McKinney’s expert
    admitted, there was no evidence that McKinney’s PTSD
    affected McKinney’s state of mind at the time of the murders.
    And Judge Sheldon found there was no link. Had Judge
    Sheldon not considered the PTSD diagnosis, forcing him to
    do so would not have altered the result. He would have given
    the PTSD diagnosis little weight (indeed, he did give it little
    weight).
    The evidence of McKinney’s childhood was much more
    compelling than his PTSD. As the majority thoroughly
    outlines, the evidence showed McKinney’s childhood was
    horrible. Id. at 9–15. But that only bolsters the conclusion that
    the Arizona courts’ alleged failure to consider McKinney’s
    PTSD was harmless. If McKinney’s horrific childhood was
    not enough to justify leniency, then why would McKinney’s
    104                 MCKINNEY V. RYAN
    resulting PTSD, which had no effect on McKinney at the time
    of the murders, have changed anything? I suppose it is
    possible that McKinney’s PTSD would have nudged Judge
    Sheldon across the line to leniency on the supposition that
    “anything is possible”; but that is not the test for harmless
    error. “Possibility” does not mean “grave doubt” that the
    failure to consider the PTSD had a “substantial and injurious
    effect or influence in determining [his] verdict.” O’Neal,
    513 U.S. at 436. The brutal nature of the Mertens murder, the
    finding that McKinney committed the two murders for
    pecuniary gain, and the fact that McKinney had committed
    multiple murders all weigh heavily in favor of the death
    penalty. The failure to consider the marginal mitigating
    weight of McKinney’s PTSD could not have affected the
    outcome. McKinney has not shown “actual prejudice,” and
    thus any error in McKinney’s sentencing was harmless.
    *    *   *
    The majority’s application of § 2254(d)(1) will have
    far-reaching effects beyond this case. Most immediately, the
    opinion potentially undermines every Arizona death sentence
    between 1989 and 2005. If we cannot find the Arizona
    Supreme Court complied with Eddings in this case, where it
    stated the Eddings standard correctly and made explicit
    findings that illustrate it observed Eddings to avoid error,
    then I don’t quite see how future cases could come out
    differently. The ineluctable effect from today’s majority is
    that, no matter what they said or did during this time period,
    Arizona courts violated Eddings. This is not idle speculation.
    MCKINNEY V. RYAN                          105
    The majority may have already passed judgment on two cases
    that are currently pending appeal before our court.44
    Most importantly, the majority’s reliance on other
    Arizona Supreme Court cases will spread to all § 2254(d)(1)
    cases. Before today, we applied the correct standard under
    § 2254(d)(1). See, e.g., Elmore v. Sinclair, 
    781 F.3d 1160
    ,
    1168 (9th Cir. 2015). After today, three-judge panels must
    abandon the correct standard and apply not the deference the
    Supreme Court instructs, but the majority’s analysis. See
    generally Miller v. Gammie, 
    335 F.3d 889
     (9th Cir. 2003) (en
    banc). We will be flooded with string citations claiming to
    show how state appellate courts have misapplied the federal
    Constitution in past cases. And petitioners will rely on those
    cases to argue we cannot presume those courts applied the
    law correctly. This cannot be how AEDPA operates, which
    this court recognized when it previously rejected the
    arguments the majority revives today.
    I conclude by noting that, today, we once again misapply
    AEDPA. But we do so only in this case. In our future cases,
    the Supreme Court should not presume we always misapply
    AEDPA because of today’s decision or because of prior
    reversals in this area. That is, one hopes the Supreme Court
    will not apply a past performance test to us similar to that
    which the majority opinion applies to the Arizona Supreme
    Court.
    I respectfully dissent.
    44
    See Martinez, 
    2008 WL 783355
    , at *33, appeal pending sub nom.
    Martinez v. Ryan, No. 08-99009 (9th Cir. May 29, 2008); Rienhardt,
    
    669 F. Supp. 2d at
    1059–60, appeal pending, No. 10-99000 (9th Cir. Jan.
    8, 2010).