Craig Ross v. Ronald Davis ( 2022 )


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  •                 FOR PUBLICATION
    UNITED STATES COURT OF APPEALS
    FOR THE NINTH CIRCUIT
    CRAIG ANTHONY ROSS,                      No. 17-99000
    Petitioner-Appellant,
    D.C. No.
    v.                     2:96-cv-02720-
    SVW
    RONALD DAVIS, Warden, California
    State Prison at San Quentin,
    Respondent-Appellee.       OPINION
    Appeal from the United States District Court
    for the Central District of California
    Stephen V. Wilson, District Judge, Presiding
    Argued and Submitted May 24, 2021
    Pasadena, California
    Filed March 25, 2022
    Before: Mary H. Murguia, Chief Judge, and Kim McLane
    Wardlaw and Consuelo M. Callahan, Circuit Judges.
    Opinion by Judge Wardlaw
    2                         ROSS V. DAVIS
    SUMMARY *
    Habeas Corpus / Death Penalty
    The panel affirmed the district court’s denial of Craig
    Anthony Ross’s habeas corpus petition in a case in which a
    jury sentenced Ross to death after convicting him of three
    counts of murder, five counts of robbery, and two counts of
    rape in concert.
    Ross claimed that an erroneous aiding and abetting
    instruction allowed the jury to find him guilty of the first-
    degree murder counts without making the finding that he had
    the intent to kill, and thus the imposition of the death penalty
    violated the Eighth Amendment under Enmund v. Florida,
    
    458 U.S. 782
     (1982). The panel concluded that the
    California Supreme Court on direct appeal reasonably
    rejected this claim. The panel wrote that the state court
    reasonably concluded that the instructions were adequate for
    the jury to make the requisite culpability finding, especially
    in light of the exception to the rule of Enmund found in Tison
    v. Arizona, 
    481 U.S. 137
     (1987), and Tapia v. Roe, 
    189 F.3d 1052
     (9th Cir. 1999).
    Ross also claimed that his trial counsel’s failure to
    investigate and present then available mitigation evidence at
    the penalty phase was ineffective assistance of counsel in
    violation of the Sixth Amendment under Strickland v.
    Washington, 
    466 U.S. 668
     (1984). The panel agreed with
    the district court that counsel’s performance during the
    penalty phase was deficient. But given the entirety of the
    *
    This summary constitutes no part of the opinion of the court. It
    has been prepared by court staff for the convenience of the reader.
    ROSS V. DAVIS                       3
    evidence before the jury, Ross’s disruptive conduct in front
    of the jury, and the sure-to-be-admitted rebuttal and
    impeachment evidence that would follow introduction of the
    mitigation evidence, the panel concluded that the California
    Supreme Court reasonably concluded that Ross did not show
    a reasonable probability that the result would have been
    different but for counsel’s unprofessional errors.
    COUNSEL
    Norman D. James (argued), Law Office of Norman D.
    James, Hamilton, Montana; Jerry L. Newton (argued),
    Carmel, California; for Petitioner-Appellant.
    Steven E. Mercer (argued) and A. Scott Hayward, Deputy
    Attorneys General; James William Bilderback II,
    Supervising Deputy Attorney General; Lance E. Winters and
    Ronald S. Mathias, Senior Assistant Attorneys General;
    Gerald A. Engler, Chief Assistant Attorney General; Rob
    Bonta, Attorney General; Office of the Attorney General,
    Los Angeles, California; for Defendant-Appellant.
    OPINION
    WARDLAW, Circuit Judge:
    Over forty years ago, Craig Anthony Ross participated
    in three brutal gang-involved home invasion robberies in
    which three people were murdered. In 1982, a jury
    convicted Ross of three counts of murder, five counts of
    robbery, two counts of burglary, and one count of rape in
    concert. The jury also found that during each offense he was
    armed with a firearm, and, as to each count of murder, found
    4                      ROSS V. DAVIS
    special circumstances of robbery-murder, burglary-murder,
    and multiple murder. On one of the murder counts, the jury
    found a rape-murder special circumstance. At the penalty
    phase, the jury returned a verdict of death. Ross now appeals
    from the denial of his federal petition for a writ of habeas
    corpus.
    Two penalty phase claims are before us. First, Ross
    claims that an erroneous aiding and abetting instruction
    allowed the jury to find him guilty of the first-degree murder
    counts without making the finding that he had the intent to
    kill, and thus the imposition of the death penalty violated the
    Eighth Amendment. See Enmund v. Florida, 
    458 U.S. 782
    (1982). We conclude that the California Supreme Court on
    direct appeal reasonably rejected this claim. The state court
    reasonably concluded that the instructions were adequate for
    the jury to make the requisite culpability finding, especially
    in light of the exception to the rule of Enmund found in Tison
    v. Arizona, 
    481 U.S. 137
     (1987) and our decision in Tapia v.
    Roe, 
    189 F.3d 1052
     (9th Cir. 1999).
    Second, Ross claims that his trial counsel’s failure to
    investigate and present then available mitigation evidence at
    the penalty phase was ineffective assistance of counsel in
    violation of the Sixth Amendment under Strickland v.
    Washington, 
    466 U.S. 668
     (1984). Though we agree with
    the district court that counsel’s failure to perform was
    deficient, given the entirety of the evidence before the jury,
    Ross’s disruptive conduct in front of the jury and the sure-
    to-be-admitted rebuttal and impeachment evidence that
    would follow introduction of the mitigation evidence, the
    California Supreme Court reasonably concluded that Ross
    did not show a reasonable probability that the result would
    have been different but for counsel’s unprofessional errors.
    ROSS V. DAVIS                                5
    I.
    Throughout his murder trial, Ross was represented by
    lead counsel Gerald D. Lenoir, an experienced capital
    defense attorney. Lenoir was assisted by co-counsel
    H. Elizabeth Harris, who had tried a single prior capital case.
    The California Supreme Court in its 1995 opinion in Ross’s
    direct appeal, 1 recited the facts related to Ross’s guilt,
    People v. Champion, 2 
    9 Cal. 4th 879
     (1995), modified on
    denial of reh’g (June 1, 1995), as follows:
    1. Murders of Bobby Hassan and His Son,
    Eric
    On the morning of December 12, 1980,
    Mercie Hassan left her home at 849 West
    126th Street, Los Angeles, to go to work.
    Residing with her were her husband, Bobby
    Hassan (an unemployed carpenter who sold
    marijuana and sometimes cocaine), and their
    four children. Mercie spoke to Bobby on the
    telephone between 11:00 and 11:30 that
    morning. Bobby normally picked up their
    1
    Though Ross does not raise any guilt phase claims on appeal, a
    summary of the guilt phase evidence is necessary to evaluate Ross’s
    penalty phase claims. See Eddings v. Oklahoma, 
    455 U.S. 104
    , 112
    (1982) (“[T]he Eighth Amendment requires consideration of the
    character and record of the individual offender and the circumstances of
    the particular offense.”) (internal quotation marks and ellipsis omitted);
    
    Cal. Penal Code § 190.3
    (a) (stating that a sentencing jury shall take into
    consideration, among other relevant factors, “[t]he circumstances of the
    crime of which the defendant was convicted . . . and the existence of any
    special circumstances”).
    2
    Ross was jointly tried and convicted for the three murders with his
    cousin and fellow gang member Steve Champion.
    6                  ROSS V. DAVIS
    14-year-old son, Eric, from school at noon
    and brought him home for lunch.
    Sometime around noon, Elizabeth Moncrief,
    a nurse working for an elderly woman across
    the street from the Hassan residence, saw
    Bobby and Eric return home. Half an hour
    later, she saw a large gold or cream-colored
    Cadillac containing 4 Black males, ages 19–
    25, parked in front of the Hassan home.
    Moncrief went outside and took a close look
    at the car. About five minutes later, she saw
    two of the men get out of the car and knock
    at the Hassans' door. There was a struggle at
    the door, and the two men entered. The other
    two men then got out of the car and entered
    the house, and someone closed the curtains in
    the Hassan residence.
    Later, Moncrief saw all four men leave the
    house. One was holding a pink pillowcase
    with something in it; the others were carrying
    paper bags containing unknown items.
    Moncrief was able to get a particularly good
    look at the last man who left the house, a tall
    man with heavy lips, a scar on his face, and
    either a chipped tooth or a gap between his
    teeth. She paid closer attention to this man
    because she had seen him once in Helen
    Keller Park, which was just across the street.
    Mercie Hassan returned home at about
    3:30 p.m. The house had been ransacked.
    Part of the lunch she had prepared for Bobby
    and Eric was on the floor, along with
    ROSS V. DAVIS                     7
    wrapping paper from the children's
    Christmas presents. Several of the presents
    were missing, as were some colored
    pillowcases and a .357-caliber Ruger
    Security Six revolver. Police, called to the
    scene, found the bodies of Bobby and Eric
    Hassan in the bedroom, lying on the bed.
    Each had been shot once in the head. Bobby's
    hands were tied behind his back, and three
    rings and a necklace he customarily wore
    were missing.
    Defendant Champion was arrested on
    January 9, 1981. When arrested, he was
    wearing a yellow metal ring with white
    stones and a gold chain necklace that
    contained a charm bearing half of a king-of-
    hearts playing card.         Mercie Hassan
    identified the ring and charm as belonging to
    her husband, Bobby. Latent fingerprints
    lifted from the Christmas wrapping paper and
    from a white cardboard box matched
    defendant Ross's fingerprints.
    [. . .]
    A ballistics expert testified that Bobby
    Hassan was killed by a .357-caliber bullet
    with rifling characteristics; the latter are
    produced by the gun that fired the bullet, and
    were described by the expert as “six lands and
    grooves with a left hand twist.” The expert
    also testified that most Colt revolvers
    produce these particular characteristics. The
    prosecution produced photographs, found in
    8                  ROSS V. DAVIS
    defendant Champion's home, showing each
    defendant holding a Colt revolver. [. . .]
    2. The Murder of Michael Taylor
    During the evening of December 27, 1980,
    three men came to the door of Cora Taylor's
    apartment at 11810 ½ Vermont Avenue, not
    far from the Hassan home. Residing with
    Cora were her son Michael (who sold
    marijuana) and her daughter Mary. The men,
    one of whom Cora identified at trial as
    defendant Ross, walked into the living room
    and asked to speak to Michael. When
    Michael and Mary came out of the next room,
    accompanied by William Birdsong, a friend
    who was visiting, one of the men, whom Cora
    and Mary later identified as Evan Malett,
    grabbed Birdsong. A struggle ensued, which
    ended when Malett drew a gun and ordered
    Cora, Mary, Michael, and Birdsong to sit on
    the bed. Malett then demanded money and
    drugs. When Mary said they did not have
    any, one of the three men hit her in the jaw
    with his fist. The men then ordered the
    Taylors and Birdsong to lie face down on the
    bed, opened Cora's purse, and ransacked the
    premises. While the three robbers were
    rummaging through the apartment, a fourth
    man (apparently a lookout) came to the door
    but did not enter.
    At Cora's urging, Michael told the robbers
    that there was money in a box in the kitchen.
    At that point one of the men, whom Mary
    ROSS V. DAVIS                     9
    later identified as defendant Ross, grabbed
    Mary by the hair and forced her to go into the
    bathroom, where he raped her. He then left
    the bathroom, returning moments later to
    rape Mary again. Thereafter, Malett entered
    the bathroom and unsuccessfully tried to rape
    Mary.
    The three men then ordered Birdsong and
    Cora to join Mary in the bathroom. A short
    time later, Cora and Mary heard a shot. After
    a few minutes, they left the bathroom and
    found Michael in the living room, dead. A
    prosecution expert testified that Michael had
    died from a single shot from a high-powered
    weapon (such as a .357 magnum), fired at
    close range. The agent also testified that the
    gun used to kill Bobby Hassan could not have
    been the murder weapon, but that the bullet
    could have been fired by the .357-caliber
    Ruger stolen from the Hassan home.
    Missing from the Taylor's apartment was an
    8-track tape player. Also missing was a
    Christmas present—a photo album—which
    had been taken out of its wrapping.
    Later that night, shortly after midnight, Los
    Angeles County Deputy Sheriff Ted Naimy
    saw a brown Buick automobile that contained
    four Black males and did not have its
    headlights turned on in the neighborhood
    where Michael Taylor had been murdered.
    As the Buick pulled alongside of him, Deputy
    Naimy and his partner ordered it to stop.
    10                  ROSS V. DAVIS
    Instead, the car sped away. As the deputies
    pursued the Buick, it went out of control,
    struck a curb, and came to a halt. Its four
    occupants jumped out of the car and ran.
    Inside the car, the deputy found the 8-track
    tape player stolen from the Taylor apartment
    and the .357-caliber Ruger revolver stolen
    from the Hassan home. The gun contained
    two live rounds and an empty shell casing,
    and smelled as if it had recently been fired.
    Under the car, Deputy Naimy found the
    photograph album stolen from the Taylors.
    Police searched the neighborhood for the
    occupants of the Buick. They found Evan
    Malett hiding in a backyard of a nearby
    house, in which defendant Champion was
    living.
    Natasha Wright, the Taylors' next-door
    neighbor, identified defendant Ross at trial as
    one of the men she saw arrive at the Taylors'
    apartment. Prosecution experts testified that
    two latent fingerprints lifted from the bathtub
    in the Taylors' apartment belonged to Ross,
    and that spermatozoa found on Mary's pants
    were consistent with Ross's blood type,
    which is shared by roughly 11 percent of the
    population. [. . .]
    3. Other Prosecution Evidence at the Guilt
    Phase
    [. . .]
    ROSS V. DAVIS                      11
    The prosecution also offered expert
    testimony that both defendants were
    members of the Raymond Avenue Crips, a
    gang whose territory encompassed the houses
    where the murders occurred; that defendant
    Ross's nickname in the gang was “Little Evil”
    or “Evil;” and that defendant Champion's
    gang nickname was “Trecherous,” “Trech,”
    or “Mr. Trech,” all standing for treacherous.
    [. . .]
    In addition, the prosecution introduced a tape
    recording of a conversation between
    defendants that took place in a bus
    transporting them from jail to court.
    [. . .]
    In the two tape-recorded conversations,
    which contained numerous profanities,
    defendants fantasized about taking a “stroll”
    out of the jail and about “blow [ing] up” the
    driver of the transport van and escaping.
    They spoke in derogatory terms of a man
    named Ishimoto, apparently a guard at the
    jail, calling him a “little Jap,” a “Buddha head
    motherfucker,” and a “little bastard Buddha
    head.” Their conversations also included the
    following interchange, in which they talked
    about Bobby Hassan, Jr., the son of victim
    Bobby Hassan and a “junior member” of
    defendants' gang, the Raymond Avenue
    Crips. . . . According to the prosecution, in
    this interchange defendants discussed
    whether Bobby Hassan, Jr., had told the
    12                  ROSS V. DAVIS
    police about defendants' participation in the
    murder of his father and brother, and
    discussed whether the bed on which victims
    Bobby and Eric Hassan were lying when they
    were shot was a waterbed:
    CHAMPION: “Man, shit. I saw that mother
    fucker Bobby Hassan.
    ROSS: “Bobby Hassan what you mean?
    CHAMPION: “His father—the one that got
    killed.
    ROSS: “A picture?
    CHAMPION: “No, I saw him. He's in the
    courtroom.
    ROSS: “What you mean? He's dead.
    CHAMPION: “No (inaudible) (laughs) the
    other (inaudible).
    ROSS: “Oh, the Raymond Crip.
    CHAMPION: “Yeah.
    CHAMPION: “He always be at all the courts,
    Cuz.
    ROSS: “Yeah?
    ROSS V. DAVIS                      13
    CHAMPION: “(Laughs) Him and his mother
    . . . his other brother and shit. I look at him
    raw—the mother fucker (laughs).
    ROSS: “He's in court (inaudible)?
    CHAMPION: “Yeah, he be at all my courts.
    I look at him raw, the mother fucker (laughs).
    I was sleepy and just woke up . . .
    ROSS: “He ain't never said nothing?
    CHAMPION: “No, he's a punk ass.
    ROSS: “They supposed to be witnesses?
    CHAMPION: “No, they just come to see
    what's happening with me. (Laughs) See if
    I'm going to get convicted and shit.
    ROSS: “(Inaudible)
    CHAMPION: “(Inaudible)
    ROSS: “Was that a waterbed in that room?
    CHAMPION: “Uh-uh.”
    Defendant Ross offered no evidence at the
    guilt phase.
    Champion, 
    9 Cal. 4th at
    898–901, 909–10.
    After one day of deliberation, the jury found Champion
    and Ross guilty of burglarizing the Hassan home and
    14                    ROSS V. DAVIS
    robbing and killing Bobby and Eric Hassan. It also
    convicted Ross of burglarizing the Taylor residence, of
    robbing Cora, Michael, and Mary Taylor, of raping Mary,
    and of murdering Michael. As the verdicts were being read,
    Ross and Champion rose and attempted to leave the
    courtroom, participating in the following exchange with the
    trial court:
    THE COURT: Mr. Champion, Mr. Ross,
    we’re not finished.
    CHAMPION: Not no more to hear.
    THE COURT: Have a seat until we finish
    reading the verdicts. Mr. Champion, Mr.
    Ross—
    CHAMPION: What more I gotta hear? I ain’t
    got no more to hear.
    THE COURT: We have further proceedings.
    Mr. Ross, Mr. Champion, have a seat.
    CHAMPION: I ain’t sitting down in this
    court. Let me go back in there.
    THE COURT: Mr. Ross, Mr. Champion,
    have a seat.
    CHAMPION: I’m not sitting down, your
    Honor, simple as that.
    THE COURT: All right.            Ladies and
    gentlemen of the jury, I’m going to excuse
    you at this point from the courtroom. Want
    ROSS V. DAVIS                     15
    you to go into the jury room just a few
    minutes. Do not discuss this case—
    (The defendants resume their seat at counsel
    table).
    THE COURT: All right. It will not be
    necessary at this time. Continue reading the
    verdicts.
    As the verdicts continued to be read, Ross and Champion
    again rose and were escorted out of the courtroom after the
    following exchange:
    THE COURT: Mr. Champion, Mr. Ross—
    CHAMPION: Fuck that, man. Get out this
    mother fucker, man.
    The California Supreme Court also recited the evidence
    presented at the penalty phase:
    At the penalty phase of the trial, the
    prosecution presented the following evidence
    of violent criminal conduct involving
    defendant[] Ross.
    [. . .]
    On July 29, 1977, Mark Howard, a gang
    member, was in Helen Keller Park when
    Walter Gregory approached and said that
    defendant Ross wanted to talk to him.
    Howard walked to another part of the park
    and spoke to Ross, who was with a group of
    16                         ROSS V. DAVIS
    people. Ross demanded that Howard return
    a radio that Howard had taken from Gregory.
    Howard said he took the radio because
    Gregory owed him money. When Howard
    refused to return the radio, Ross produced a
    revolver, and said that if Howard did not
    return the radio he would blow Howard's
    head off. Howard then slapped Ross,
    whereupon Ross shot Howard six times in the
    stomach and the chest. Howard recovered,
    but a bullet remains lodged close to his spine,
    and his ability to use his left leg is seriously
    impaired. As a result of this incident,
    defendant Ross entered a plea of guilty to a
    charge of assault with a deadly weapon, and
    was sentenced to three years in prison. [. . .]
    Champion, 
    9 Cal. 4th at
    901–04.
    Though Ross’s defense counsel failed to call any
    witnesses in mitigation, they did introduce three pieces of
    evidence by stipulation and judicial notice. 3 First, the parties
    stipulated that, if called, the prosecution’s gang expert would
    have testified that Mark Howard, who had been another
    shooting victim of Ross, was previously a “peripheral
    member” of two different gangs. This evidence impeached
    Howard, who had testified he was never a member of a gang.
    Second, the parties stipulated that Ross was twenty-one
    years old at the time of the three murders. Finally, at
    defendants’ request, the trial court took judicial notice that a
    jury had found Evan Malett guilty of eight felonies for his
    role in the Taylor home invasion murder, that one of the
    3
    The California Supreme Court incorrectly stated that “Ross offered
    no evidence at the penalty phase.” Champion, 
    9 Cal. 4th at 904
    .
    ROSS V. DAVIS                        17
    felonies was first degree murder with the personal use of a
    firearm, and that the total sentence Malett received was
    46 years to life imprisonment. At the prosecution’s request,
    the court also took judicial notice that the jury in Malett’s
    case was instructed that personal use of a firearm included
    merely displaying the firearm or striking someone with it,
    and that the jury found not true the allegation that Malett
    personally inflicted great bodily injury on Taylor.
    Arguing for the death sentence, the prosecutor asserted
    that Ross continued to present a danger to society. The
    prosecutor relied not only on Ross’s recorded statements
    about committing a violent escape from custody, but also
    “the display that was put on . . . when the verdicts were
    rendered.” According to the prosecutor, when the verdicts
    were being read, “Mr. Ross engaged in a confrontation with
    the guards here and almost got into a fight with them.” As a
    result, Ross was not “the kind of person from whom we can
    protect not only the society outside of prison but society
    inside prison by incarcerating him for the rest of his life.”
    The prosecutor also emphasized the “brutal and cold-
    blooded” nature of the murders and pointed to Ross’s
    shooting of Mark Howard as “a[nother] murder where the
    victim, fortunately, did not die.” The prosecutor, however,
    conceded that “we didn’t prove beyond a reasonable doubt,
    I thought, that either of the defendants actually was a shooter
    in any of these murders.” Nevertheless, the prosecutor
    maintained that the evidence showed that Ross was the
    leader because: (1) he had “the nerve” to shoot Howard in
    broad daylight; (2) he was the one who previously had spent
    time in state prison; (3) he told Mary that he was the leader;
    (4) he did most of the talking during the recorded
    conversation with Champion; and (5) when the verdicts were
    being read, “he was the one who first got up and in mock
    18                     ROSS V. DAVIS
    indignation started to walk toward the lockup, [and]
    Mr. Champion followed.”
    The prosecutor anticipated the defense’s argument that
    Ross deserved a life sentence because Malett’s jury found
    him guilty of being the actual shooter, and yet did not impose
    the death penalty. The prosecutor first distinguished
    Malett’s case from Ross’s because Malett was found guilty
    of the Taylor murder only, whereas Ross was found guilty
    of the Hassan murders as well. Moreover, unlike in Ross’s
    case, the jury in Malett’s case did not find true the special
    circumstance allegations. Additionally, based on the jury
    instructions, Malett’s conviction for personal use of a
    firearm did not necessarily mean that the jury found him
    guilty of being the shooter in the Taylor murder; in fact, the
    jury actually found untrue the allegation that Malett
    personally inflicted great bodily injury on Taylor. Finally,
    the prosecutor noted that “it’s not the test for your purposes
    as to whether or not this case is more or less aggravated than
    some other case.”
    For his part, Ross’s counsel Lenoir argued that a
    sentence less than death meant that Ross would “die in
    prison” because escape from Folsom prison was “an utter
    impossibility.” According to Lenoir, the question was
    “whether or not [Ross] c[ould] be useful by making license
    plates” because “[t]hat’s where they’re made, prison.”
    Comparing Ross’s case to Malett’s, Lenoir pointed out
    that, unlike Malett, Ross was not charged with the personal
    use of a firearm or the infliction of great bodily injury on
    Taylor. Yet, while “Malett c[ould] look forward to getting
    out of jail and being back on the streets,” Ross “c[ould] never
    dream of getting out.”
    ROSS V. DAVIS                        19
    As for Ross’s outburst during the reading of the verdicts,
    Lenoir noted, and Champion’s counsel agreed, that
    Champion was the one who stood up first. Additionally,
    Lenoir claimed that the courtroom bailiff “ha[d] [no]
    problems” with Ross until “two persons from the audience,”
    who apparently were plainclothes deputies, “ran over
    towards” him and Champion as they were walking to the
    lock-up area.
    Lenoir also attempted to mitigate the assault on Mark
    Howard. He explained, “I don’t say that [Howard] deserved
    to have been shot, but certainly he instigated it by slapping
    Ross.” Moreover, Lenoir noted that, even though Howard
    “denied being connected with any gang,” the prosecution
    “graciously . . . assisted me in . . . entering into the
    stipulation” that Howard in fact had gang affiliations.
    Finally, Lenoir argued that there were four specific
    mitigating circumstances. First, the jury “c[ould] reasonably
    infer that Mr. Ross behaved during the two years he was in
    prison” for the Howard shooting because “if there was one
    black mark on [his] record[,] . . . it would have been
    presented.” Second, because Ross was then only twenty-
    three years old, he had “a long time [remaining in his life] to
    think about one thing, what I’m in [prison] for.” Third, Ross
    told Mary in the bathroom that “he would see [that her]
    mother was not hurt, and [her] mother was not hurt.” Lastly,
    “it ha[d] been conceded that there [wa]s no evidence that
    Ross had a gun at any time during these actions.”
    The jury began penalty phase deliberations, and, after
    two days, delivered death verdicts against Ross and
    Champion.
    20                     ROSS V. DAVIS
    II.
    Ross appealed his convictions and his sentence to the
    California Supreme Court. The state court affirmed both his
    convictions and his sentence but struck as duplicative all but
    one of Ross’s multiple murder special circumstances.
    Champion, 
    9 Cal. 4th at 952
    . The state court also addressed
    Ross’s Enmund claim. It held that, although the jury
    instructions inadequately described the mens rea for aiding
    and abetting, that error was harmless because the
    instructions on the special circumstance allegations, found
    true by the jury, required that the “defendants shared the
    intent of the killers when they aided and abetted the
    murders.” 
    Id.
     at 928–29.
    Ross concurrently filed a habeas petition in the
    California Supreme Court, in which he raised ineffective
    assistance of counsel at the penalty phase. In re Ross,
    
    10 Cal. 4th 184
    , 187 (1995). The state court issued an order
    to show cause and appointed a Los Angeles Superior Court
    judge as a Referee to take evidence and make findings as to
    whether trial counsel was ineffective in the penalty phase for
    failing to present available mitigation evidence. 
    Id. at 189
    .
    Specifically, the state court asked the Referee to make six
    findings:
    1) What      mitigating    character      and
    background evidence could have been,
    but was not, presented by petitioner at his
    penalty trial?
    2) What investigative steps by trial counsel,
    if any, would have led to such items of
    evidence?
    ROSS V. DAVIS                      21
    3) What investigative steps, if any, did trial
    counsel take in an effort to gather
    mitigating evidence to be presented at the
    penalty phase?
    4) What tactical or financial constraints, if
    any, weighed against the investigation or
    presentation of mitigating character and
    background evidence at the penalty
    phase?
    5) What evidence damaging to petitioner,
    but not presented by the prosecution at
    the guilt or penalty trials, would likely
    have been presented in rebuttal if
    petitioner had introduced any such
    mitigating character and background
    evidence?
    6) Did petitioner himself request that either
    the investigation or the presentation of
    mitigating evidence at the penalty phase
    be curtailed in any manner? If so, what
    did petitioner request?
    
    Id.
     at 189–90.
    The Referee conducted an evidentiary hearing (known as
    a “reference hearing” under California law), took extensive
    evidence, answered the six questions asked by the state
    court, and then offered his opinion that had counsel
    performed adequately and presented the mitigating
    evidence, there was a reasonable probability that Ross would
    not have been sentenced to death. 
    Id.
     at 189–201. The
    California Supreme Court accepted the Referee’s factual
    determination as to the then available mitigation evidence.
    22                      ROSS V. DAVIS
    
    Id. at 205
    . It upheld most, but not all, of the Referee’s factual
    findings, but disagreed with its legal conclusions, which it
    reviewed de novo. The court “accept[ed] for purposes of
    discussion that [counsel’s] performance was indeed
    deficient,” 
    id. at 201
    , but did not “decide whether counsel’s
    performance was truly deficient, or merely obscured by the
    fog of time,” 
    id. at 204
    , as nine years had elapsed between
    the trial and the reference hearing. Noting that it had
    deliberately not asked the Referee to opine on the ultimate
    question of whether Ross was prejudiced by counsel’s
    performance, the court did not find the Referee’s conclusion
    as to prejudice persuasive, particularly as the record
    reflected that the Referee had not reviewed the trial record
    to compare the actual trial with the hypothetical trial that
    would have occurred had counsel performed effectively.
    The state court concluded that although the mitigating
    evidence was substantial, it did not stand alone, but was
    “subject to substantial impeachment and potentially
    devastating rebuttal.” 
    Id. at 205
    . “[C]omparing the trial as
    it actually occurred with the trial as it would have been with
    the mitigating evidence,” the California Supreme Court
    determined that Ross was not prejudiced. 
    Id. at 213
    .
    Ross then sought federal habeas relief in the Central
    District of California under 
    28 U.S.C. § 2254
    . Ross v. Davis,
    No. CV 96-2720 SVW, 
    2017 WL 2374101
    , at *1 (C.D. Cal.
    Apr. 26, 2017). The district court held that the California
    Supreme Court reasonably concluded that counsel’s
    deficient performance at the penalty phase did not prejudice
    Ross and properly denied his Enmund claim in light of the
    Tison exception. 
    Id., at *20, 53
    . The district court then
    granted a certificate of appealability as to the Strickland
    claim, which we expanded to include the Enmund claim.
    ROSS V. DAVIS                       23
    III.
    We have jurisdiction pursuant to 
    28 U.S.C. §§ 1291
    ,
    2253(a). We review a district court’s denial of habeas relief
    de novo. Avena v. Chappell, 
    932 F.3d 1237
    , 1247 (9th Cir.
    2019), cert denied, 
    140 S. Ct. 1137
     (2020); Sanders v.
    Cullen, 
    873 F.3d 778
    , 793 (9th Cir. 2017).
    The Antiterrorism and Effective Death Penalty Act of
    1996 (AEDPA), Pub. L. No. 104-132, 
    110 Stat. 1214
    ,
    controls our analysis of Ross’s petition for both his Enmund
    claim and his Strickland ineffective assistance of counsel
    claim. Under AEDPA, we must defer to the state court’s
    decision with respect to any claim adjudicated on the merits
    unless the decision was: (1) “contrary to, or involved an
    unreasonable application of, clearly established Federal law,
    as determined by the Supreme Court of the United States”;
    or (2) “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). “This is a ‘difficult to
    meet,’ and ‘highly deferential standard for evaluating state-
    court rulings, which demands that state-court decisions be
    given the benefit of the doubt.’” Cullen v. Pinholster,
    
    563 U.S. 170
    , 181 (2011) (citations omitted). Our review is
    “limited to the record that was before the state court that
    adjudicated the claim on the merits.” 
    Id.
    For Ross’s ineffective assistance of counsel claim,
    “Strickland v. Washington and its progeny constitute the
    clearly established federal law.” Andrews v. Davis, 
    944 F.3d 1092
    , 1107–08 (9th Cir. 2019) (en banc) (citing Pinholster,
    
    563 U.S. at 189
    , and Strickland, 
    466 U.S. at 668
    ). To
    establish ineffective assistance of counsel under Strickland,
    Ross must demonstrate two elements: first, that defense
    counsel’s performance was deficient, and second, that the
    deficient performance prejudiced the defense. Prejudice is
    24                        ROSS V. DAVIS
    shown where “there is a reasonable probability that, but for
    counsel’s unprofessional errors, the result of the proceeding
    would have been different.” Strickland, 
    466 U.S. at 687, 694
    . Because AEDPA guides our review, the question
    before us is whether the California Supreme Court “applied
    Strickland to the facts of [t]his case in an objectively
    unreasonable manner.” Bell v. Cone, 
    535 U.S. 685
    , 699
    (2002). “The standards created by Strickland and § 2254(d)
    are both highly deferential, and when the two apply in
    tandem, review is doubly so.” Harrington v. Richter,
    
    562 U.S. 86
    , 105 (2011) (quotations and citations omitted).
    In determining whether a state court decision is an
    unreasonable application of Strickland, “[w]e consider only
    the evidence that was before the state court at the time of its
    ruling.” Avena, 932 F.3d at 1247 (quoting Pinholster,
    
    563 U.S. at 182
    ).
    IV.
    Ross was not charged with or proven to be the actual
    killer of either Taylor or the Hassans. 4 He contends that the
    State was required to prove he had the specific intent to
    commit murder to impose the death penalty. Two Supreme
    Court cases decided before the California Supreme Court
    affirmed Ross’s convictions and death sentence on direct
    appeal clearly establish the law governing when a defendant
    who is convicted of felony murder, but who is not the actual
    killer, may be given a sentence of death: Enmund v. Florida,
    
    458 U.S. 782
     (1982) (decided two months before Ross’s trial
    began), and Tison v. Arizona, 
    481 U.S. 137
     (1987).
    4
    According to the California Supreme Court, Evan Malett was
    charged with and convicted of the murder of Michael Taylor. In re Ross,
    
    10 Cal. 4th at 210
    .
    ROSS V. DAVIS                           25
    In Enmund, the Supreme Court reversed the death
    sentence of a Florida man under that state’s felony-murder
    rule. Enmund, 
    458 U.S. at 801
    . Enmund’s role in the
    robbery was to wait in the car by the side of the road, while
    two others robbed the elderly victims, and then to drive the
    get-away car. 
    Id. at 784
    . The Court focused on Enmund’s
    culpability—not that of the co-defendants who committed
    the murders. Because Enmund did not kill, attempt to kill,
    or have any intention of participating in or facilitating a
    murder, his culpability was “plainly different” from that of
    those who committed the murder. 
    Id. at 798
    . The Court,
    therefore, held that imposition of the death sentence was
    impermissible under the Eighth Amendment. 
    Id.
    Tison presented more egregious facts. There, the three
    Tison brothers “helped their father and his cellmate—both
    convicted murderers—escape from prison, armed them with
    shotguns, helped flag down and kidnap a family on an
    isolated road, drove the family [which included a two-year-
    old] to a remote site, and then stood by as their father and his
    cellmate murdered [them].” Dickens v. Ryan, 
    740 F.3d 1302
    , 1311 (9th Cir. 2014) (en banc) (citing Tison, 
    481 U.S. at
    139–41). The Court distinguished the Tisons’ culpability
    from Enmund’s: “their degree of participation in the crimes
    was major rather than minor, and the record would support a
    finding of the culpable mental state of reckless indifference
    to human life.” Tison, 
    481 U.S. at 151
    . The Court held that
    “major participation in the felony committed, combined with
    reckless indifference to human life, is sufficient to satisfy the
    Enmund culpability requirement” for imposition of the death
    penalty. 
    Id. at 158
    . 5
    5
    “[T]he reckless disregard for human life implicit in knowingly
    engaging in criminal activities known to carry a grave risk of death
    26                         ROSS V. DAVIS
    Thus, following the Supreme Court’s decisions in
    Enmund and Tison, the Eighth Amendment permits
    imposition of the death penalty in the case of a “felony
    murderer who actually killed, attempted to kill, or intended
    to kill.” 
    Id. at 150
    . It also permits the imposition of the death
    penalty in the case of a felony murderer “whose participation
    [in the felony] is major and whose mental state is one of
    reckless indifference to the value of human life.” 
    Id. at 152
    .
    A.
    The State first argues that Ross’s Enmund claim is
    procedurally barred. We disagree. The State mistakenly
    asserts that Ross’s Enmund claim was raised for the first time
    in his successive 1999 state habeas petition, which the
    California Supreme Court denied on the merits as untimely
    under In re Robbins, 
    18 Cal. 4th 770
    , 780–81 (1998), and
    barred under In re Dixon, 
    41 Cal. 2d 756
    , 759 (1953),
    because it was not raised on direct appeal when it could have
    been. But Ross challenged his death sentence under Enmund
    on direct appeal, arguing in his opening brief that the
    instructions permitted his death sentence “without even a
    determination that [he] intended to commit a felony, much
    less intended to kill,” and referencing Enmund. Ross again
    referred to Enmund error in his reply brief on direct appeal,
    where he argued that the State had failed to respond to it as
    represents a highly culpable mental state, a mental state that may be
    taken into account in making a capital sentencing judgment when that
    conduct causes its natural, though also not inevitable, lethal result.”
    Tison, 
    481 U.S. at
    157–58. This is because the “reckless indifference to
    the value of human life may be every bit as shocking to the moral sense
    as an ‘intent to kill.’ Indeed it is for this very reason that the common
    law and modern criminal codes alike have classified behavior such as
    occurred in this case along with intentional murders.” 
    Id.
     (citations
    omitted).
    ROSS V. DAVIS                        27
    an issue. And, in a supplemental brief filed after Tison v.
    Arizona was decided, Ross argued that “[s]ince it cannot be
    determined from the present record that any finding of intent
    to kill was made, reversal is required under Enmund v.
    Florida, Tison v. Arizona, and their progeny.” Because a
    claim is exhausted for federal habeas purposes when it is
    “fairly presented to the state courts,” Picard v. Connor,
    
    404 U.S. 270
    , 275 (1971), Ross’s repeated challenges to his
    death sentence on Enmund grounds in his direct appeal are
    sufficient to preserve the claim for habeas relief.
    B.
    1.
    Ross contends that the jury instructions given at his state
    trial negated Enmund’s requirement of proof that he killed,
    attempted to kill, or intended to kill the Hassans or Michael
    Taylor, primarily because Enmund “held that it was a
    violation of the Eighth Amendment to impose the death
    penalty under the felony murder rule or as an aider and
    abettor” in the absence of such proof.” He also argues that
    the California Supreme Court’s denial of this claim was
    contrary to and an unreasonable application of the Supreme
    Court decisions in Enmund, Tison, and Cabana v. Bullock,
    
    474 U.S. 376
     (1986). On habeas review, we “must examine
    the entire course of the state-court proceedings . . . to
    determine whether, at some point in the process, the requisite
    factual finding as to the defendant’s culpability has been
    made.” 
    Id. at 387
    . If the requisite finding has been made, it
    is presumed correct under 
    28 U.S.C. § 2254
    (d), “and unless
    the habeas petitioner can bear the heavy burden of
    overcoming the presumption,” his Enmund claim fails. 
    Id. at 388
    .
    28                        ROSS V. DAVIS
    As the California Supreme Court acknowledged, 6 the
    jury instruction on aiding and abetting liability was
    inadequate to describe the specific intent required to convict
    Ross of aiding and abetting the three killings. Champion,
    
    9 Cal. 4th at 929
    . The instruction allowed Ross to be
    convicted if the murders were “the natural and reasonable or
    probable consequences of any act that he knowingly aided
    or encouraged,” or “if, with knowledge of the unlawful
    purpose of the perpetrator of the crime, he aids, promotes,
    encourages, or instigates by act or advice the commission of
    such crime.” 
    Id.
     at 927–28 nn.17–18. This instruction was
    given in error because it was “sufficiently ambiguous” to
    permit conviction upon the “finding of an intentional act
    which aids, without necessarily requiring a finding of an
    intent to encourage or facilitate the criminal offense.” 
    Id. at 928
    .
    Despite the erroneous aider or abettor instruction, the
    California Supreme Court determined that the error was
    rendered harmless by the special circumstances instruction.
    The jury was instructed that it could find the special
    circumstances true “if defendant was not the actual killer”
    only if it found that he “intentionally aided, abetted,
    counseled, commanded, induced, solicited, requested or
    assisted the actual killer in the commission of the murder in
    the first degree.” 
    Id. at 929
    . The California Supreme Court
    reasoned that the import of this instruction was reinforced by
    the prosecutor, who in his closing argument explained, “[i]t
    6
    The court never once characterized this as an Enmund claim, but
    instead relied on analogous state law to discuss the substance of that
    claim. Champion, 
    9 Cal. 4th at
    927–29. Under AEDPA, however, “a
    state court’s decision need not cite or even be aware of controlling
    Supreme Court precedent, so long as it does not contravene those
    precedents.” Andrews, 944 F.3d at 1116–17.
    ROSS V. DAVIS                        29
    must therefore be established, before you can convict
    defendants of special circumstances, that . . . they share,
    along with the trigger man, the intent that these victims
    perished in the course of these crimes.” Id. at 928–29.
    Therefore, the California Supreme Court concluded, “when
    the jury in this case found the special circumstance
    allegations true, it also necessarily found that defendants
    shared the intent of the killers when they aided and abetted
    the murders.” Id. at 929. Thus, the erroneous aiding and
    abetting instruction did not prejudice Ross.
    This conclusion was neither “contrary to” nor an
    “unreasonable application of” Enmund.                Enmund’s
    culpability requirement for imposition of the death penalty
    is proof beyond a reasonable doubt that Ross killed,
    attempted to kill, or intended to kill the Hassans and Michael
    Taylor. Because the prosecution offered no evidence to
    prove Ross was the actual killer, the jury could find true the
    special circumstances allegations only if it found Ross had
    the intent to assist in killing the victims. And the jury found
    true the multiple murder special circumstances, under
    instructions that required a finding of a shared intent to kill.
    Id.; see also People v. Neely, 
    6 Cal. 4th 877
    , 898 (1993)
    (holding that a felony-murder special circumstance
    instruction “properly required that the jury find that
    defendant, if he was only an aider and abettor, had the intent
    to kill”); People v. Pinholster, 
    1 Cal. 4th 865
    , 954 (1992)
    (explaining that a special circumstance instruction requiring
    that defendant “intentionally aided, abetted, counseled,
    commanded, induced, solicited, requested, or assisted the
    actual killer” means the jury forms a determination on
    whether the defendant had the intent to kill) (emphasis
    omitted); People v. Sanders, 
    51 Cal. 3d 471
    , 516–17 (1990)
    (same); People v. Warren, 
    45 Cal. 3d 471
    , 487 (1988)
    (same).
    30                     ROSS V. DAVIS
    The state court’s determination that the special
    circumstances instruction included the necessary specific
    intent to satisfy Enmund’s culpability requirement was
    reasonable. We have previously addressed an inadequate
    aiding and abetting instruction in a pre-AEDPA case. In
    Tapia v. Roe, the aiding and abetting instruction given to the
    jury was erroneous because “it failed to instruct the jury to
    find ‘intent to encourage or facilitate the criminal offense.’”
    Tapia, 
    189 F.3d at 1056
     (quoting People v. Beeman, 
    35 Cal. 3d 547
    , 561 (1984). We found the error harmless under
    either the Brecht v. Abrahamson, 
    507 U.S. 619
     (1993) or the
    Chapman v. California, 
    386 U.S. 18
     (1967) standards of
    review, in light of the jury’s separate determinations that the
    defendant was guilty of lying-in-wait and multiple-murder
    special circumstances, which necessarily showed that the
    jury found the defendant had or shared the specific intent to
    kill both of the victims. Tapia, 
    189 F.3d at
    1056–57. This
    was the “equivalent” of finding the erroneously omitted
    intent element of aiding and abetting. We concluded “if the
    jury did find Tapia guilty on an aiding and abetting theory,
    rather than as the actual perpetrator, the omission of the
    intent element from the aiding and abetting instruction could
    not have had an ‘injurious effect or influence in determining
    [their] verdict,’ Brecht, 
    507 U.S. at 637
    , and was ‘harmless
    beyond a reasonable doubt,’ [under] Chapman, 
    386 U.S. at 24
    .” Id. at 1057.
    This case is distinguishable from the circumstances
    presented in Cabana. There, the Court invalidated a death
    sentence imposed under a Mississippi law that allowed any
    robbery participant to be convicted of capital murder
    “notwithstanding the defendant’s own lack of intent that any
    killing take place.” Cabana, 
    474 U.S. at 379
    . The jury
    instructions allowed the conviction based on an intent to rob
    without any finding of an intent to kill. 
    Id. at 380
    . Because
    ROSS V. DAVIS                       31
    “the jury may well have sentenced [the defendant] to death
    despite concluding that he had neither killed nor intended to
    kill; or it may have reached its decision without ever coming
    to any conclusion whatever on those questions,” the Court
    found the death sentence constitutionally inadequate under
    Enmund. 
    Id. at 384
    . Here, by contrast, the special
    circumstances instruction required the jury to make the
    finding satisfying Enmund.
    2.
    Moreover, to the extent Ross alternatively contends that
    there was insufficient evidence from which a jury could find
    major participation and reckless indifference under Tison,
    we disagree, as Ross was a major participant in the crimes
    committed and demonstrated a reckless indifference to
    human life.
    a.
    First, there was ample evidence that Ross was a major
    participant in the felonies. Our decision in Dickens is
    instructive. There, we rejected an assertion of Enmund error,
    reasoning that Dickens’s participation in the two murders
    was less like that of Enmund’s passive get-away role and
    more like the conduct of the Tison brothers. Dickens,
    740 F.3d at 1311. As in Tison, Dickens participated in the
    events leading up to the killings of two victims. Dickens
    suggested to his co-defendant Amaral, who had a history of
    violence, that they plan a robbery, id. at 1306, and then he
    drove Amaral to a highway rest site where the robbery was
    to take place and waited for three hours until their chosen
    victims arrived, id. at 1307. Dickens then watched and
    waited while Amaral used Dickens’s gun to rob and murder
    the victims. Id. Dickens made no effort to help the victims
    but picked up Amaral and drove to Dickens’s brother’s
    32                     ROSS V. DAVIS
    house, where the pair burned the stolen wallet, split the cash,
    and went their separate ways. Id. at 1308. “In short, Dickens
    was actively involved in every aspect of the deadly crime—
    suggesting they undertake the robbery, planning the robbery,
    staking out the crime scene, selecting the victims, arming
    Amaral with a handgun, watching the murders, aiding
    Amaral’s escape, destroying evidence, and helping Amaral
    evade capture.” Id. at 1311.
    Here, like Dickens, Ross was “present at the murder site
    and did not interfere with the murders.” Id. at 1311. In fact,
    Ross was even more actively involved in the crimes resulting
    in the Taylor and Hassan murders. Ross’s participation in
    the Hassan robbery was demonstrated through the
    fingerprint evidence found on the wrapping paper inside the
    Hassan home, indicating Ross had entered the house and
    participated in the robbery while the killings took place.
    Champion, 
    9 Cal. 4th at 898
    . Days later, after participating
    in the Hassan robbery where two victims were shot and
    killed, Ross took an active role in the Taylor home-invasion
    robbery, raped one of the victims twice, told her that he was
    the leader of the group ransacking the house, and assisted in
    separating Mark Taylor from the rest of the family just
    before Taylor was shot and killed. 
    Id.
     at 899–901. Ross
    “continued the joint venture when he . . . failed to report the
    crimes.” Dickens, 740 F.3d at 1311 (quotations omitted).
    And Ross could have anticipated the use of deadly force,
    even if he never pulled the trigger himself, because he knew
    his colleague “had [a] weapon with him for the robberies.”
    Id.
    As in Dickens, Ross “was actively involved in every
    aspect of the deadly crime,” and was thus “clearly a major
    participant.” Id. And because “Tison does not illuminate the
    precise line where a defendant’s conduct becomes major
    ROSS V. DAVIS                        33
    participation . . . even assuming [Ross’s] conduct falls into a
    grey area between Enmund and Tison, we must defer to the
    [California] Supreme Court’s conclusion.” Id. at 1312.
    b.
    Ross also “knowingly engaged” in the home-invasion
    robbery, an activity “known to carry a grave risk of death.”
    Tison, 
    481 U.S. at 157
    . This mental state “may be taken into
    account in making a capital sentencing judgment when that
    conduct causes its natural, though also not inevitable, lethal
    result.” 
    Id.
     at 157–58.
    We have previously rejected the argument that armed
    robbery is not a crime known to carry a grave risk of death.
    See Dickens, 740 F.3d at 1314. Ross does not attempt to
    argue, nor are we aware of any authority, to the contrary.
    And the armed robberies in this case posed even graver risk
    of death as they were gang-orchestrated home invasion
    robberies of small-time drug dealers. Champion, 
    9 Cal. 4th at
    898–901; see also United States v. VonWillie, 
    59 F.3d 922
    ,
    929 (9th Cir. 1995) (accepting that drug dealers often
    possess and use weapons to protect their drugs and
    intimidate potential buyers). Ross knew at least one of his
    colleagues had a gun. Champion, 
    9 Cal. 4th at 900
    . The
    purpose of the unlawful entry was to look for drugs and
    money associated with drug sales. 
    Id.
     This is precisely the
    type of activity that is known to carry a grave risk of death.
    See Dickens, 740 F.3d at 1314 (holding that the defendant
    was aware of a grave risk of death when he knew that his
    colleague had a violent and explosive temper, a history of
    violence, and that he recklessly handled guns, yet proceeded
    with participating in the robbery knowing his colleague had
    a gun). And after the shootings, Ross chose to “aid those
    whom he had placed in the position to kill rather than [aid]
    their victims.” Tison, 
    481 U.S. at 152
    . The state courts could
    34                     ROSS V. DAVIS
    reasonably have found that Ross demonstrated reckless
    disregard to human life.
    V.
    We next address Ross’s claim that his counsel provided
    ineffective assistance in the penalty phase, primarily by
    failing to investigate and present readily available mitigating
    evidence. To understand what that evidence was and
    whether it was then available, the California Supreme Court
    referred the matter to a Referee.
    A.
    The Referee found that fifteen witnesses were available
    to testify at the time of Ross’s trial. They would have
    testified to Ross’s childhood and family circumstances but
    they were never called to testify. These witnesses included
    Ross’s mother, Gloria Brown, along with Ross’s siblings and
    step-siblings, and several other family members with
    personal knowledge of mitigating evidence.
    The Referee found that all of the evidence recounted
    below was readily available to the defense and was not
    presented at trial. In re Ross, 
    10 Cal. 4th at 195
    .
    1.
    a. Violence Inflicted on Mother by Ross’s father, Stafford
    Ross’s mother, Gloria Brown, testified that during her
    short marriage to Ross’s biological father Stafford, Stafford
    beat and stabbed her on multiple occasions. When she was
    eight months pregnant with Ross, Stafford pushed her
    against a wall and she fell, causing Ross to be born
    prematurely the next morning. When Ross was an infant,
    ROSS V. DAVIS                       35
    Gloria left Stafford, but he insisted that she take him back.
    When she refused, he stabbed her multiple times, puncturing
    her lung, and she was saved only because her police
    detective brother was able to fend Stafford off until
    additional officers arrived.
    b. Abuse by Stepfather Henry Brown
    After Stafford went to prison for the stabbing, Gloria
    lived alone with Ross and her five other children. She had
    difficulty making ends meet. In 1963, when Ross was about
    four years old, the family began living with Henry Brown,
    Gloria’s future husband. In 1966 or 1967, Brown’s three
    sons began living with them as well.
    Brown would drink often, and “when he drank, he would
    become violent.” He was especially violent after gambling
    losses at the horse track. He physically and verbally abused
    Gloria, cutting her many times. He once chased her around
    the kitchen, causing her to be burned by flaming grease from
    a skillet. On another occasion, Brown hoisted a television
    set to throw at Gloria, but Gloria’s sister, “grabbed a knife
    out of the kitchen drawer and threatened him, so he would
    put [the television set] down.” Several times, Brown
    threatened to kill Gloria, and Gloria’s police detective
    brother had to come to disarm Brown. After these types of
    incidents, Brown would apologize to Gloria and buy her
    flowers.
    Ross and the other children witnessed this abuse and
    were also abused themselves. Brown severely “whooped the
    kids,” especially Ross, possibly because Ross “would
    become very emotional . . . by seeing his mother being beat
    up.” Holding the children upside down, Brown would whip
    them all over their bodies with “a big wide thick belt,” and
    with large switches off the backyard peach tree. As a result,
    36                     ROSS V. DAVIS
    the children, including Ross, suffered welts, bruises, and
    cuts.
    Brown also abused the children in other ways. He forced
    them to kneel in the garage and stare at the wall for long
    periods of time ranging from “a couple of hours” to
    “sometimes half a day.” He refused to allow Ross to meet
    his biological father, Stafford Ross. One day, Brown locked
    Ross’s younger sister out of the house, and when she
    attempted to enter through the window, he “came at [her]
    with [a] butcher knife.” After this incident, the sister, who
    was a high school freshman at the time, moved out of the
    house. Ross’s older sister also had moved out earlier when
    she was fourteen years old due to “the violence that
    happened in the house.” The children’s nicknames for
    Brown were “monster,” “ski ball head motherfucker,” and
    “the devil.”
    Around late 1970, when Ross was twelve years old,
    Gloria went to an attorney and had Brown removed from the
    home. After they were separated, Brown refused to allow
    his sons to spend time with Gloria’s sons, but they still
    managed to do so in secret. In 1978, while Ross was in
    prison for the Howard shooting, Brown apparently
    “changed,” and Gloria reunited with him. Gloria and Brown
    were living together again at the time of Ross’s trial.
    c. Neighborhood Violence
    Ross grew up in a “pretty rough” neighborhood. There
    were “a lot of gangs” and the children “couldn’t play out in
    the streets . . . because [they] would get attacked by the gang
    people.” Around the time of Gloria and Brown’s separation,
    Ross at age twelve began associating with the gang members
    on the street.
    ROSS V. DAVIS                        37
    d. Ross’s Good Character
    Ross’s family members also testified to his good
    character. When Ross was between the ages of about six and
    fourteen, he visited his grandparents’ “large acreage” each
    summer. On these trips, Ross was very respectful and did
    all the chores he was asked to do.
    Ross showed great affection for his siblings and cousins.
    He babysat them, watched over them at the local park,
    helped teach them how to draw and write, and “always
    entertain[ed] them.” He walked his sisters to school and
    protected them from bullies. His younger sister recalled: “If
    Henry [Brown] would only allow us to have one sandwich,
    [Ross] would give me his sandwich. . . . One particular
    incident . . . [Ross] stood in front of me and told [Brown]
    don’t whoop me, that he’ll take my whooping for me.” And
    according to his aunt, Ross “was like a protector of the
    children.”
    Moreover, Ross’s stepbrother and brother both testified
    that Ross helped them turn around their lives. Specifically,
    when Ross was twenty-one years old, after the stepbrother’s
    young daughter drowned in 1980, he went “on an alcohol
    binge,” but Ross “worked with [him] very hard and told
    [him] that it wasn’t going to bring [his] baby back, and he
    would stick with [him] and made sure [he] didn’t go back
    [to] drinking again.” Similarly, around 1977, Ross’s brother
    “was into smoking a lot of weed,” but Ross “didn’t like that”
    and talked to him and introduced him to bodybuilding. As a
    result, Stafford Ross, Jr. “got it together” and went on to win
    third place in a “Mr.           Los Angeles” bodybuilding
    competition.
    When asked if, in spite of Ross’s crimes, he would have
    testified at Ross’s penalty phase that Ross was a person of
    38                     ROSS V. DAVIS
    good character, Ross’s police detective uncle answered:
    “[K]nowing the way that he was abused, misused, hurt,
    knowing what he has seen his mother go through, knowing
    that the only people that he had contact with were the people
    out on the streets, who were gang-members, yes, I would
    have said yes.”
    e. School and Institutional History
    Gloria and one of Ross’s sisters testified about a race-
    fueled incident at Ross’s public school. When Ross was in
    the fifth or sixth grade, one of his teachers called him the N-
    word. Ross was “really upset” and told his mother that “he
    hated to go to the class” and “didn’t want to go [back].”
    Gloria “went to the school to talk to the teacher, and the
    teacher denied it.” Gloria believed Ross, but she did not
    “press the issue further.”
    In 1970 and 1971, when Ross was twelve and thirteen
    respectively, Ross received “an honor award for outstanding
    achievement in safety” and “a first place award for the
    shotput.” Before Gloria and Brown’s separation, Ross’s
    grades were passing, if “not particularly exemplary,” but
    afterward he began getting even lower grades. One of
    Ross’s aunts also testified that Ross began getting into
    trouble after Gloria and Brown’s separation.
    By stipulation, the Referee admitted into evidence
    Gloria’s statements to Ross’s juvenile probation officers.
    According to a 1973 probation report: “[Gloria] stated that
    she feels other boys influenced [Ross] negatively. He is very
    cooperative at home. [Gloria] asserted that [Ross] needs
    male guidance and hopes that he can have a male probation
    officer with much supervision.          [Ross] has a poor
    relationship with the [separated] stepfather.”
    ROSS V. DAVIS                        39
    According to a 1974 report: “[Gloria] state[d] that she
    would like to try [Ross] home again. ‘I feel [the California
    Youth Authority] would make him only bitter. I don’t think
    there is anything wrong with him psychologically. He is
    always warm with his family. . . . I never had any problem
    with [him] until after Mr. Brown and I separated. There was
    no male supervision. . . .” In that report, Gloria also stated:
    “[Ross] takes his punishment. He does feel remorse,
    although he doesn’t show it. He would write letters to us
    stating that he’s done wrong and had to pay for his mistakes.
    He wrote ‘It’s time I become a better person’ and said he
    would pray for himself.”
    In a 1975 report, however, Gloria’s view had changed:
    “I am completely unable to control or understand [Ross]. I
    have done all I can for him, and out of my six children, he is
    by far the worst.” Moreover, she stated that Ross “has a hate
    for whites, shows a great deal of resentment towards all
    types of people,” and she did not want him released from
    juvenile custody.
    Finally, one of Ross’s sisters testified to his difficulties
    following his release from prison in 1980. Ross “went to the
    Urban League with [her] and he wanted a job,” but “he didn’t
    know what he was doing with the [applications].” Ross
    could write poetry, but he lacked “the technical skills . . . to
    get him in a training program” or understand the “jargon” on
    the applications.
    f. Availability of Witnesses
    Ross’s family members who testified at the reference
    hearing stated that they would have testified at his penalty
    phase and asked the jury to spare his life, but they were never
    interviewed by the defense. While attending portions of
    Ross’s trial, Gloria “briefly” had conversations with Harris
    40                    ROSS V. DAVIS
    and “one brief conversation with [Lenoir] in the hallway”
    during which he told her that Ross “should take a plea
    bargain.” “[N]obody approached [her] about testifying.”
    Additionally, two of Ross’s aunts and two of his sisters
    testified that they came to court, but when they attempted to
    speak to Lenoir or Harris, they were either rudely ignored or
    “brushed” or “shunned” away. Another aunt testified that,
    at Gloria’s direction, she came to court one day because “the
    attorney wanted her to have some character witnesses for
    [Ross].” As potential witnesses, she and Gloria were
    excluded from the courtroom for portions of the proceedings
    that day. When the day ended without them testifying,
    counsel said, “We’ll call you,” but she “never heard anything
    else from them.”
    Ross’s post-conviction investigator testified that he
    called Gloria in 1986 and arranged a meeting. At the
    meeting about two weeks later, Gloria gathered
    approximately fifteen family members, and the investigator
    spent eleven or twelve hours interviewing them in one day.
    2.
    Ross also called the members of his trial defense team as
    witnesses at the reference hearing. By that time, Lenoir had
    retired and was in poor physical health. He could no longer
    remember “the specifics” of the case but he could remember
    there were “no financial impediments” to investigating.
    Additionally, it appears that, after Ross’s trial, Lenoir
    directed defense investigator Charles Watson and co-
    counsel Harris to hand over their trial files to him.
    Subsequently, “appellate counsel repeatedly requested
    access to the files over a two-year period and during that
    period received no replies. Only when the files were
    subpoenaed to a court hearing did [Lenoir] assert that they
    ROSS V. DAVIS                        41
    had been lost.” At the reference hearing, Lenoir testified that
    he lost the files when he moved offices.
    In an earlier deposition, Lenoir stated that he talked to
    Gloria “many times” about the case, and that Ross told him
    that he did not want his mother called as a witness.
    Champion’s counsel also recalled Lenoir stating that “he
    would have liked to call [Ross’s] family members” as
    witnesses, but that Ross either did not want him to call his
    family members or did not want him to call his mother
    specifically.
    Investigator Watson “vaguely recall[ed]” that, in
    preparation for the penalty phase, he interviewed and
    subpoenaed two of Ross’s friends. At Lenoir’s direction,
    Watson also telephoned Gloria and asked her and another
    family member to appear in court on one specific day during
    the penalty phase.
    Lenoir placed Harris in charge of preparing for the
    penalty phase of the trial. Harris testified she prepared for
    the penalty phase by speaking with Ross, Gloria, and several
    other members of Ross’s family, including Brown. These
    conversations were likely conducted either over the
    telephone or in the courthouse hallway. Harris’s impression
    from these conversations was that “Ross came from a very
    stable supportive middle-class type family environment,”
    and she told Lenoir that she thought some of the family
    members would make good witnesses.
    Harris also testified that “the final decision was that
    Mr. Lenoir simply told me that we weren’t going to put on
    any evidence.” She and Lenoir never discussed the
    possibility that the prosecution might present rebuttal
    evidence if the defense presented the testimony of Ross’s
    family members.          Harris neither obtained Ross’s
    42                      ROSS V. DAVIS
    institutional records nor went or sent an investigator to
    Ross’s house to conduct interviews. Additionally, Ross
    never told her “not to put any witnesses on to testify in his
    behalf.” Harris testified that, in hindsight, she had lacked the
    skills to “go deep enough” and “pick up on the[ ] clues” that
    Ross may have been abused, such as Ross’s “very emphatic”
    statement to her that Brown was not his father, or Gloria’s
    “reluctance in talking about the family situation.” Harris
    concluded: “I absolutely feel I did not do a competent job at
    the penalty phase, . . . and I’m not happy to say that, but
    that’s true.”
    According to Lenoir’s billing records, Lenoir spent a
    total of 114.5 hours preparing for the guilt and penalty
    phases in this case. Robert Bryan, an experienced capital
    defense attorney, testified that “looking at this billing by
    itself . . . certainly raises . . . questions” about Lenoir’s
    “performance.” Bryan also testified that “child abuse
    evidence . . . can often make a substantial difference” in a
    penalty phase, and that it is “very common” for a capital
    defendant to ask counsel not to present a mitigation case or
    call particular witnesses. In Bryan’s opinion, competent
    counsel in 1982 would have conducted interviews of family
    members, retained a mental health expert to investigate
    issues such as child abuse, and obtained available
    institutional records.
    3.
    At the reference hearing, the State presented evidence
    that it would have sought to introduce in rebuttal if Ross had
    offered the additional mitigation evidence. This included
    evidence of Ross’s juvenile adjudications for three counts of
    burglary involving the theft of guns, four counts of robbery,
    and one adjudication for brandishing a “barbeque fork” at a
    cook while at a probation camp.              These juvenile
    ROSS V. DAVIS                       43
    adjudications were excluded from evidence during the
    penalty phase of Ross’s trial, but the Referee found that “the
    trial court would have permitted the prosecutor to introduce
    [evidence of these adjudications] on rebuttal.” In re Ross,
    
    10 Cal. 4th at 199
    .
    In addition, the State presented Ross’s own statements to
    his probation officer in 1978 that he had no remorse about
    the Howard shooting, felt that he had acted in self-defense,
    and was not concerned about going to prison. The State also
    relied on Ross’s statements in a psychiatric report “prepared
    for Los Angeles County Juvenile Court proceedings in 1974,
    when [Ross] was 15.” 
    Id.
     There, Ross stated that “he had
    never been beaten or physically abused by anyone, that he
    liked his stepfather, Brown, and had gotten along well with
    him, and that he felt better when there was a man at home
    fulfilling the role of father. [Ross], who had been held at a
    camp, said that he wanted to go home.” 
    Id.
     at 199–200.
    Psychiatrist Michael Coburn, however, testified at the
    reference hearing that adolescents “frequently deny that they
    have been abused.”
    The State also presented evidence of four instances of
    misconduct by Ross while at Deuel Vocation Institution in
    1978 and 1979, but the Referee “found that the prosecution
    probably could not have presented [this] evidence” at the
    penalty phase because the witnesses had no memory of the
    events. 
    Id.
     at 199–200, 207. The California Supreme Court
    “accept[ed] this finding.” In re Ross, 
    10 Cal. 4th at 207
    .
    4.
    Following the hearing, the Referee filed an eleven-page
    report containing his factual findings in response to the six
    questions that the California Supreme Court had referred to
    him. The Referee first found that Ross’s fifteen family
    44                     ROSS V. DAVIS
    members who testified at the hearing “were sincere,” that
    their testimony “inspire[d] confidence, trust, sympathy, and
    belief,” and that “they were amicable, willing, and anxious
    to testify now and would have been so in 1982.” After
    summarizing these witnesses’ testimonies with varying
    levels of accuracy, the Referee concluded that the penalty
    phase jury would have deemed the evidence of abuse
    suffered by Ross “believable” and “significant,” “could
    [have] easily believed” the evidence of Ross’s good
    character, and could have “infer[red]” and found
    “instructive” that Ross “was negatively and severely
    affected by the family breakup and enforced isolation from
    his stepbrothers.”
    Next, the Referee found that the “customary and indeed
    mandatory” steps of interviewing family members,
    obtaining relevant records, and employing mental health
    experts “would have led to all of the evidence adduced at the
    reference hearing.” The Referee concluded that, “sad to say,
    nothing, absolutely nothing of a competent nature was done
    by way of penalty phase preparation by defense counsel in
    this case.” There were no tactical or financial reasons for the
    “virtually non-existent” penalty phase preparation, including
    “no investigation regarding rebuttal.” Further, “[a]lthough
    [Ross] indicated some concerns about his mother’s health
    and her being called as a witness,” the Referee found “no
    substantial evidence to support any reasonable conclusion
    that [Ross] requested curtailment of the presentation of
    penalty phase evidence.”
    With regard to potential rebuttal evidence, the Referee
    found that the prosecution would have presented Ross’s
    juvenile record and conducted “extensive cross-examination
    of [Ross’s] witnesses.” Nevertheless, based on the evidence
    adduced during the reference hearing, the Referee opined
    ROSS V. DAVIS                        45
    that “such [rebuttal] evidence would have been outweighed
    by [Ross’s] mitigating evidence and that it is reasonably
    probable that a more favorable determination would have
    resulted in the absence of defense counsel’s failings.”
    B.
    To establish deficient performance by counsel, Ross
    must demonstrate that counsel’s representation “fell below
    an objective standard of reasonableness . . . under prevailing
    professional norms.” Strickland, 
    466 U.S. at 688
    . The
    relevant inquiry is not what defense counsel could have
    done, but rather whether the choices made by defense
    counsel were reasonable. See Babbitt v. Calderon, 
    151 F.3d 1170
    , 1173 (9th Cir. 1998). Courts “must indulge a strong
    presumption that counsel’s conduct falls within the wide
    range of reasonable professional assistance; that is, the
    defendant must overcome the presumption that, under the
    circumstances, the challenged action might be considered
    sound trial strategy.” Strickland, 
    466 U.S. at 689
     (quotations
    omitted). This means “strategic choices made after thorough
    investigation of law and facts relevant to plausible options
    are virtually unchallengeable.” 
    Id. at 690
    .
    However, “counsel has a duty to present and explain all
    available mitigating evidence, absent a tactical reason for not
    doing so.” Demetrulias v. Davis, 
    14 F.4th 898
    , 913 (9th Cir.
    2021). After all, “fail[ing] to present important mitigating
    evidence in the penalty phase—if there is no risk in doing
    so—can be as devastating as a failure to present proof of
    innocence in the guilt phase.” Hamilton v. Ayers, 
    583 F.3d 1100
    , 1113–14 (9th Cir 2009) (quoting Mak v. Blodgett,
    
    970 F.2d 614
    , 619 (9th Cir. 1992) (per curiam)). To uncover
    mitigating evidence, “counsel has a duty to make reasonable
    investigations or to make a reasonable decision that makes
    particular investigations unnecessary.” Strickland, 
    466 U.S. 46
                        ROSS V. DAVIS
    at 691; see also Wiggins v. Smith, 
    539 U.S. 510
    , 523 (2003)
    (explaining that in analyzing deficient performance, instead
    of focusing on whether counsel should have presented a
    mitigation case, the court should instead analyze “whether
    the investigation supporting counsel’s decision not to
    introduce mitigating evidence . . . was itself reasonable”).
    Satisfying this duty requires counsel “to conduct a thorough
    investigation of the defendant’s background.” Williams v.
    Taylor, 
    529 U.S. 362
    , 396 (2000).
    According to the Referee’s findings, however, counsel
    failed to fulfill that obligation, and thus performed
    deficiently. The California Supreme Court accepted for
    purposes of discussion the Referee’s finding that defense
    counsel’s “performance was indeed deficient.” In re Ross,
    
    10 Cal. 4th at 201, 204
    . However, the California Supreme
    Court also stated that it “need not decide whether counsel’s
    performance was truly deficient” and focused its analysis
    solely on Strickland’s prejudice prong. 
    Id. at 204
    . Because
    the issue of deficient performance was left unadjudicated by
    the California Supreme Court, we review this issue de novo.
    Porter v. McCollum, 
    558 U.S. 30
    , 39 (2009); see also Avena,
    932 F.3d at 1248. Nonetheless, to the extent the California
    Supreme Court accepted the Referee’s findings of fact, we
    afford them a presumption of correctness under AEDPA.
    See 
    28 U.S.C. § 2254
    (e)(1) (providing that “a determination
    of a factual issue made by a State court shall be presumed to
    be correct.”); Avila v. Galaza, 
    297 F.3d 911
    , 921 (9th Cir.
    2002) (noting that “AEDPA requires us to presume that the
    referee’s factual findings are correct” when they have been
    adopted by the state court).
    The Referee found that the “customary and indeed
    mandatory” steps of interviewing family members,
    obtaining relevant records, and employing mental health
    ROSS V. DAVIS                       47
    experts “would have led to all of the evidence adduced at the
    reference hearing[ ].” According to the Referee, Lenoir “had
    delegated responsibility for the preparation of the penalty
    phase” to Harris, and “the only penalty phase preparation
    performed by her were 2 or 3 perfunctory conversations in
    or about the court hallway with family members.” Further,
    the Referee found that there were no tactical or financial
    justifications for the “virtually non-existent” penalty phase
    preparation, there was “no investigation regarding rebuttal,”
    and there was “no substantial evidence to support any
    reasonable conclusion that [Ross] requested curtailment of
    the presentation of penalty phase evidence.” The California
    Supreme Court did not reject any of these findings.
    Based upon the Referee’s findings, trial counsel could
    have investigated and presented the mitigation evidence
    presented at the reference hearing, but they did not do so.
    The California Supreme Court acknowledged that this
    evidence was “substantial” enough that, “[i]f it stood alone,”
    it “may well have . . . established prejudice.” In re Ross,
    
    10 Cal. 4th at 205
    .
    On federal habeas review, the district court, reviewing
    de novo, held there is “no reason to reject the referee’s
    finding” of deficient performance. Ross v. Davis, No. CV
    96-2720 SVW, 
    2017 WL 2374101
    , at *15 (C.D. Cal. Apr.
    26, 2017). The district court explained that after the guilt
    phase, “the jurors knew little more about [Ross] than that
    they had found him guilty on three counts of first degree
    murder, five counts of robbery, two counts of burglary, one
    count of rape, and that he was a member of a gang.” 
    Id.
     “At
    the end of the penalty phase, the only additional evidence the
    jury had was that petitioner had a prior violent felony
    conviction, resulting from his altercation with Mark
    Howard, and that Evan Malett had received a life sentence
    48                     ROSS V. DAVIS
    for his role in the Taylor murder.” 
    Id.
     The district court
    emphasized that the standard penalty phase jury instruction
    at the time of Ross’s trial “essentially required the jury to
    impose the death penalty if the evidence submitted showed
    only aggravating circumstances.” 
    Id., at *16
    . The district
    court reasoned that “counsel’s failure to present a penalty
    [phase] defense gave the jury little choice but to return a
    verdict of death.” 
    Id.
     This failure was “a gross deviation
    from what competent counsel would have done.” 
    Id.
     The
    district court concluded, “[t]here is no adversarial process
    when, in the face of three capital convictions, and multiple
    accompanying felonies, defense counsel neither thoroughly
    investigates nor puts forth mitigating evidence of any
    substance.” 
    Id.
    Like the district court, we have little difficulty
    concluding that defense counsel’s performance was
    deficient during the penalty phase. The reference hearing
    illuminated a wealth of potential mitigating evidence that
    could easily have been discovered by Ross’s counsel.
    Indeed, it took the investigator retained by habeas counsel
    just fifteen to sixteen hours over less than two weeks to
    interview all fifteen potential witnesses. In re Ross, 
    10 Cal. 4th at 196
    . Neither Lenoir nor Harris spent time obtaining
    records, employing mental health professionals, or looking
    into Ross’s background in any meaningful way to uncover
    mitigating evidence—steps that competent capital counsel
    should have taken. 
    Id.
     While counsel spoke briefly to a few
    family members, there was little (if any) follow up and none
    of the mitigating evidence was presented. 
    Id.
     There is no
    suggestion in this record that counsel was aware of the
    potential mitigating evidence and made a tactical decision
    against presenting it. Cf. Dunn v. Reeves, 
    141 S. Ct. 2405
    ,
    2412 (2021) (refusing to find deficient performance where
    the record indicated counsel was aware of the defendant’s
    ROSS V. DAVIS                       49
    mental health records and evaluations but ultimately decided
    not to hire a mental health expert because “counsel’s choice
    regarding experts involved a strategic decision entitled to a
    presumption of reasonableness.”). Here, where counsel
    “simply did not know” the mitigating evidence, this utter
    failure to investigate meant that “they could not have
    intelligently chosen one strategy over another.” Andrews,
    944 F.3d at 1112.
    C.
    To establish prejudice, Ross must demonstrate that there
    is a “a reasonable probability that, but for counsel’s
    unprofessional errors, the result of the proceeding would
    have been different.” Strickland, 
    466 U.S. at 694
    . “A
    reasonable probability is a probability sufficient to
    undermine confidence in the outcome.” 
    Id.
     When
    examining the penalty phase of a capital case, the standard
    requires “a reasonable probability that at least one juror”
    would have recommended a sentence of life instead of death.
    Wiggins, 
    539 U.S. at 537
    . This probability must be
    “substantial, not just conceivable.” Richter, 
    562 U.S. at 112
    ;
    Shinn v. Kayer, 
    141 S. Ct. 517
    , 523 (2020).
    The California Supreme Court rejected the Referee’s
    finding of prejudice. In re Ross, 
    10 Cal. 4th at 205
    . The
    state court noted that it deliberately did not ask the Referee
    to make a finding on the ultimate question of whether Ross
    was prejudiced by counsel’s performance, because that
    question is a mixed question of law and fact. 
    Id.
     To properly
    analyze the prejudice prong requires a reweighing of the
    evidence introduced and the mitigating evidence available.
    Mayfield v. Woodford, 
    270 F.3d 915
    , 928 (9th Cir. 2001).
    Here, the “record of the reference hearing indicate[d] the
    referee did not review the trial record.” In re Ross, 
    10 Cal. 4th at 205
    . The Referee therefore could not have properly
    50                     ROSS V. DAVIS
    assessed prejudice by “compar[ing] the actual trial with the
    hypothetical trial that would have taken place had counsel
    [performed] competently.” 
    Id.
    Instead, the California Supreme Court concluded that it
    was not reasonably probable that the outcome of Ross’s
    penalty phase trial would have been different had counsel
    presented the mitigating evidence.           
    Id.
        Although
    “substantial,” the mitigating evidence was somewhat weaker
    than the Referee had found. As the California Supreme
    Court described it, the “mitigating evidence consisted of the
    testimony of 15 members of petitioner’s family testifying
    primarily that they loved petitioner, that he was protective
    and caring to other family members, and that he was abused
    as a child . . . , that petitioner lived in a violent
    neighborhood, that his failure to be rehabilitated was partly
    the fault of institutional authorities, and that he expressed
    remorse for earlier crimes.” 
    Id.
     However, this mitigating
    evidence “was subject to substantial impeachment and
    potentially devastating rebuttal,” which “alters the
    equation.” 
    Id.
    Specifically, the state court recognized several
    significant areas of impeachment weakening the evidence in
    mitigation. First, the court found the psychiatric report in
    which Ross told the psychiatrist that he had never been
    beaten or abused by anyone and that he liked and got along
    well with his stepfather, Brown, would have made effective
    impeachment because it was in Ross’s own words and was
    “more contemporaneous to the alleged incidents than the
    later testimony of his relatives.” 
    Id. at 206
    . Moreover, at the
    time of trial, Gloria and Brown had reconciled and had
    begun living together. 
    Id.
     This, too, “would certainly have
    weakened the impact of the abuse evidence.” 
    Id.
     Finally,
    Gloria’s statements to the probation officer that Ross was
    ROSS V. DAVIS                        51
    cooperative at home, but that when he was with his peers he
    had no control of himself or his behavior, made “long before
    the trial, and thus closer in time to the events at issue” would
    have “undercut the mitigating evidence relating to [Ross’s]
    behavior.” 
    Id.
    When discussing the “potentially devastating rebuttal”
    evidence, the state court primarily focused on Ross’s
    juvenile criminal history. 
    Id.
     At Ross’s trial, “no evidence
    of misconduct by [Ross] before he was 18 years old” was
    presented to the jury. 
    Id.
     However, the Referee found, and
    the California Supreme Court accepted, that Ross’s juvenile
    convictions for robbery and for brandishing a weapon at
    probation camp would have been permitted as rebuttal
    evidence. 
    Id. at 207
    . Additionally, the state court
    recognized that Ross’s sustained petitions on juvenile
    burglary convictions involving theft of guns would have
    been admissible to rebut the character evidence painting
    Ross as a “kind, protective, caring person.” 
    Id.
     The court
    reasoned that the potential evidence was “not limited to any
    singular incident, personality trait, or aspect of his
    background,” so the “breadth and generality of [] good
    character evidence warranted rebuttal evidence of the scope
    offered.” 
    Id. at 208
    .
    The California Supreme Court also recognized how
    almost all of the mitigation evidence was “painfully limited”
    to Ross as a young child. 
    Id.
     The state court then
    “question[ed] how effective it would be for the defense to
    present a parade of witnesses testifying about [Ross’s] good
    qualities up to sometime around the age of 12 years, but
    necessarily leaving an obvious gap during his teen years,”
    
    id.,
     when he incurred his series of juvenile convictions and
    delinquent acts. This, the court found, opened the door to
    52                     ROSS V. DAVIS
    the rebuttal evidence proffered by the prosecution.         
    Id.
    at 208–09.
    Next, the California Supreme Court evaluated the
    defense actually presented at trial. It concluded that
    “counsel gave the penalty jury a reason to spare [Ross’s]
    life.” 
    Id. at 209
    . It found that “[c]ounsel did not simply give
    up, but had a specific tactical approach, and presented
    evidence and argument to support this approach.” 
    Id.
    (quotation and citation omitted). While defense counsel did
    not present witnesses, Lenoir did “argue[] mitigating
    inferences from the guilt phase evidence presented by the
    prosecution” and presented three items of evidence through
    stipulation and judicial notice.” 
    Id.
     at 209–10. While the
    court found that this defense was minimal, it still “presented
    a coherent case, and avoided the impeachment and rebuttal
    the new mitigating evidence would have elicited.” 
    Id. at 210
    .
    The state court then walked through all the arguments
    Ross’s defense counsel actually made in his closing
    argument. Lenoir stressed the “harshness” of a life sentence
    without the possibility of parole. 
    Id.
     He compared the fate
    of Ross’s accomplice in the Taylor murder, who was found
    to have used a firearm in the crime, but who did not receive
    a verdict of death. 
    Id.
     Counsel also argued that the
    prosecution “concede[d]” it did not prove Ross used a
    firearm during the murders. 
    Id.
    Lenoir also introduced evidence that Mark Howard, who
    Ross had assaulted, was a gang member. And Lenoir argued
    that the jury “can reasonably infer that Mr. Ross behaved
    during the two years he was in prison [for the assault of Mark
    Howard]. There is nothing to show otherwise.” 
    Id.
     This
    supported Lenoir’s argument that Ross has proven he could
    conform in a confined environment. 
    Id. at 211
    . This
    ROSS V. DAVIS                        53
    argument, “a potentially compelling one” according to the
    California Supreme Court, “could not have been made if
    counsel had produced the mitigating evidence suggested in
    this proceeding and triggered the rebuttal evidence” of
    Ross’s nonconforming behavior while in juvenile detention.
    
    Id.
     Lenoir also argued Ross’s young age was a mitigating
    factor and “discussed a mitigating circumstance of the crime,
    and mitigating facts of the Howard assault, including the
    victim’s gang membership.” 
    Id.
     The California Supreme
    Court found that “[a]ll of these circumstances would have
    justified a decision not to use the additional evidence
    presented at the reference hearing even after full
    investigation, and must be considered in deciding whether it
    is reasonably probable the result would have been different
    had the evidence been presented.” 
    Id.
    The state court acknowledged that there was no direct
    evidence, due to Lenoir’s lack of memory, that failing to
    present mitigating evidence was based on tactical reasons.
    
    Id. at 213
    . “But even if we assume[d] counsel would have
    presented the evidence,” said the court, “we conclude, after
    comparing the trial as it actually occurred with the trial as it
    would have been with the mitigating evidence, that there was
    no prejudice.” 
    Id.
     The court then cogently explained its
    reasoning:
    Petitioner was convicted of three murders on
    two separate occasions, including the cold-
    blooded killing of a father and fourteen-year-
    old son, who were shot while lying on a bed,
    one with his hands tied behind his back. He
    personally raped the sister of the third murder
    victim. Although the additional mitigating
    evidence, had it been presented, might have
    evoked sympathy, there was no compelling
    54                     ROSS V. DAVIS
    connection between that evidence and the
    crimes of this case. The crimes were gang-
    conducted robbery murders, not sudden
    explosions of angry violence or psychopathic
    serial killings. Moreover, the mitigating
    evidence would have elicited damaging
    impeachment and rebuttal evidence, with an
    inevitable adverse effect on the actual
    defense strategy at trial. For all these reasons,
    we find no reasonable probability the result
    would have been different had the mitigating
    evidence been presented.
    
    Id.
     Ross argues that the California Supreme Court’s
    rejection of his ineffective assistance of counsel claim was
    both contrary to and an unreasonable application of
    Strickland. We address these contentions in turn.
    1.
    The parties agree that once the reviewing court identifies
    all the potential mitigating evidence then available to
    competent counsel to present to the trial court, Strickland
    requires that the court reweigh the “evidence in aggravation
    against the totality of available mitigating evidence to
    determine ‘whether there is a reasonable probability that,
    absent the errors, the sentencer . . . would have concluded
    that the balance of aggravating and mitigating circumstances
    did not warrant death.’” Apelt v. Ryan, 
    878 F.3d 800
    , 832
    (9th Cir. 2017).
    Ross relies on our recent en banc decision in Andrews to
    suggest that the California Supreme Court improperly
    weighed the mitigating and aggravating circumstances. He
    also argues that the similarity of the fact patterns between
    Andrews and his case requires us to conclude that the
    ROSS V. DAVIS                       55
    California Supreme Court was unreasonable in its prejudice
    determination. As to Ross’s legal argument, our decision in
    Andrews lends no support. In contrast to the California
    Supreme Court’s careful and meticulous reweighing of the
    evidence in light of the potential mitigating evidence
    adduced in the reference hearing in Ross, the California
    Supreme Court in Andrews failed to separately analyze the
    prejudice prong. This resulted in two unreasonable
    applications of Strickland’s legal principles.
    First, we concluded in Andrews that the California
    Supreme Court committed legal error when it improperly
    conflated the two Strickland prongs. In denying habeas
    relief, the California Supreme Court held that Andrews’s
    counsel had not performed deficiently and concluded “[f]or
    the same reasons,” it was not probable that Andrews was
    prejudiced by the failure to present the potential mitigating
    evidence. Andrews, 944 F.3d at 1106. But, as we reasoned
    in Andrews, “Strickland’s two prongs serve separate
    purposes,” with the deficiency analysis focused on
    “counsel’s adherence to reasonable professional standards,
    while prejudice looks to the weight of the available evidence
    and its effect on the case.” Id. at 1116 (citing Strickland,
    
    466 U.S. at
    693–95). In Ross, the California Supreme Court
    did not commit this error. It expressly stated it was not
    addressing the deficiency prong and instead focused
    exclusively on prejudice. In re Ross, 
    10 Cal. 4th at 205
    .
    Second, in Andrews, “the California Supreme Court
    hardly engaged in the reweighing of evidence that
    Strickland’s prejudice analysis requires.”     Andrews,
    944 F.3d at 1116. Indeed, the entirety of the court’s
    “reweighing” of the evidence can be found in sixty-two
    words in a single sentence. Id. (quoting In re Andrews,
    
    28 Cal. 4th 1234
    , 1259 (2002)). Thus, we concluded even
    56                     ROSS V. DAVIS
    “giving the California Supreme Court’s analysis all the
    deference it is due along with every benefit of the doubt, only
    an unreasonable application of Strickland’s principles could
    lead to the conclusion that Andrews was not prejudiced by
    counsel’s deficient representation at the penalty phase.” Id.
    at 1117. The same is not true here. Rather, the California
    Supreme Court devoted several pages of its opinion to the
    prejudice analysis. The court discussed at length the
    aggravating and mitigating evidence actually presented at
    trial by the parties along with all the potential mitigation
    evidence, and the “inevitable adverse effect” that the
    additional rebuttal and impeachment evidence would have
    had. In re Ross, 
    10 Cal. 4th at
    205–13. Considering that
    “AEDPA demands that ‘state-court decisions be given the
    benefit of the doubt,’” Andrews, 944 F.3d at 1116 (quoting
    Pinholster, 
    563 U.S. at 181
    ), the thorough analysis by the
    California Supreme Court here cannot fairly be compared to
    the brief aside the California Supreme Court gave to its
    Strickland prejudice analysis in Andrews.
    And as to the facts, although there are some similarities
    between the crimes for which Andrews and Ross were
    convicted, Andrews involved readily available potential
    mitigating evidence of such an order of magnitude that the
    failure to investigate and present that evidence, and the
    California Supreme Court’s denial of habeas relief under
    Strickland, represented “the type of ‘extreme malfunction []’
    in the operation of a state’s criminal justice system that
    justifies the intervention of a federal habeas court.”
    Andrews, 944 F.3d at 1099 (quoting Richter, 
    562 U.S. at 102
    ).
    Like Ross’s crimes, the “facts of Andrews’s crimes
    inspire little sympathy.” Andrews, 944 F.3d at 1100.
    Andrews participated in a drug-related robbery that resulted
    ROSS V. DAVIS                        57
    in the murders of three persons. He was convicted of the
    first-degree murder of those persons, rape, sodomy, and
    robbery, and the jury found four special circumstances to be
    true, making him eligible for the death penalty. Id. The jury
    sentenced Andrews to death on each of the murder counts.
    Id. at 1101.
    As in Ross’s case, Andrews’s lead defense counsel, who
    was also Gerald Lenoir, made a limited presentation during
    the penalty phase. Defense counsel stipulated that Andrews
    was twenty-nine at the time of the murders and that Andrews
    had previously pleaded guilty in Alabama to armed robbery,
    escape, and robbery, stipulations which the prosecutor
    introduced into evidence. Id. Defense counsel submitted
    sworn affidavits explaining that in connection with
    Andrews’s prior murder conviction, it was his co-defendant
    who actually used a firearm to kill the victim. Id. No
    witnesses for the defense were called. Id.
    In both cases, the California Supreme Court affirmed the
    convictions on direct review. In both cases, on habeas
    review, the court appointed a Los Angeles Superior Court
    judge to conduct a reference hearing and to take evidence
    and answer a series of questions. And this is where the two
    cases diverge in the nature, extent, and gravity of the readily
    available mitigating evidence.
    The prosecutor in Andrews’s case portrayed him as a
    “vicious animal.” Id. at 1099. Defense counsel failed to
    employ the “standard investigative techniques” and “simple
    persistence” that would have revealed humanizing evidence
    that could have allowed the jury to understand how it was
    that Andrews came to commit these violent crimes. Id.
    at 1101. As eloquently described in Andrews, as a result of
    counsel’s deficient performance:
    58                     ROSS V. DAVIS
    The jury . . . did not know—because it was
    never told—anything about Andrews’s
    upbringing in a segregated and impoverished
    area of Mobile, Alabama.             Andrews’s
    counsel did not tell the jury that Andrews, as
    a child, had been confined to the Alabama
    Industrial School for Negro Children known
    as “Mt. Meigs”—a segregated, state-run
    institution that, in the words of one witness,
    was a ‘slave camp for children.’ The jury was
    not told that, during these formative years,
    Andrews was repeatedly subject to brutal
    abuse at the hands of his state custodians. It
    was not told that, from the age of fourteen,
    Andrews was in the custody of Alabama state
    institutions so degrading that federal courts
    later found the conditions in those institutions
    violated the Eighth Amendment’s prohibition
    on cruel and unusual punishment. Nor was
    the jury told that, in the view of mental health
    experts, the severe abuse Andrews suffered
    made his subsequent criminal behavior
    understandable and predictable.
    Id. at 1099.
    The mitigating evidence withheld during the penalty
    phase in Andrews’s case cannot be understated. A witness
    testified, “the children committed to Mt. Meigs in the 1960s
    had ‘no chance of rehabilitation’ and ‘came out much worse’
    than when they entered. Indeed, the institution was ‘not
    designed for rehabilitation.’” Id. at 1102. Children instead
    “pick[ed] cotton and tend[ed] vegetables.” Id. And if that
    weren’t enough, “[a]t night, there was little supervision,
    leading to ‘a lot of sexual abuse of children.’” Id. Thirteen
    ROSS V. DAVIS                       59
    witnesses who had been committed to Mt. Meigs detailed its
    abhorrent conditions. One witness recalled a truly disturbing
    disciplinary trend:
    When a child was disobedient in the fields or
    failed to pick his quota of cotton, an overseer
    would “poke a hole in the ground and order
    him to lie down, to pull down his pants, and
    to stick his penis into the hole. The overseer
    would then beat the boy’s thighs with a stick,
    often until the skin burst open. One witness
    remembered seeing [Andrews] beaten in this
    manner.”
    Id. It was reported that, because of Andrews’s “young age
    and slight build,” he was often the target of “substantial
    sexual pressure,” particularly from “older, tougher boys,
    from whom no protection or separation was provided.” Id.
    at 1103. This physical and sexual abuse continued after
    Andrews’s incarceration “[j]ust months after his release
    from Mt. Meigs”: Andrews’s “counsel presented evidence at
    the state court hearing that Andrews was ‘repeatedly raped
    in prison.’” Id. And a former inmate described Andrews as
    a “little sheep among wolves, a baby among a bunch of
    grownups.” Id. Like Mt. Meigs, the prison in which
    Andrews was detained had debilitating conditions, and
    because it was newly integrated, “many of the [w]hite prison
    guards resented the [b]lack prisoners, whom they called
    ‘things’ and ‘niggers.’” Id.
    Andrews’s defense counsel’s closing argument was
    extremely limited. Defense counsel “gave a short, rambling
    closing statement” that “overwhelmingly focused on
    Andrews’s age,” and argued that Andrews’s age alone “can
    be sufficient mitigation.” Andrews, 944 F.3d at 1101.
    60                     ROSS V. DAVIS
    Defense counsel “veered from topic to topic,” ineffectively
    arguing that Andrews didn’t pull the trigger in his prior
    murder conviction, and that his current co-defendant
    received a life sentence. Id.
    Our en banc court held that “it is unconscionable and
    unreasonable to uphold a sentence of death when the jury
    never heard readily available mitigating evidence of the
    magnitude present here.” Id. We upheld the district court’s
    grant of habeas relief on Andrews’s claim of ineffective
    assistance of counsel at the penalty phase. Id.
    By contrast, here, it was not unreasonable for the
    California Supreme Court to conclude that the potential
    mitigation evidence—which is limited to Ross as a young
    child—was likely insufficient to give the jury a basis to
    understand why Ross would engage in such heinous crimes
    as an adult. Arguably, it might have swayed one juror to
    vote for life upon hearing fifteen relatives ask for mercy, but
    it was not unreasonable for the California Supreme Court to
    have concluded otherwise. We therefore do not believe
    Andrews controls the outcome of this case.
    It also bears mentioning that defense counsel’s closing
    argument on behalf of Ross was more detailed than on behalf
    of Andrews, particularly with respect to mitigating
    inferences. As the California Supreme Court reasonably
    concluded in Ross, defense counsel “gave the penalty jury a
    reason to spare his life.” In re Ross, 
    10 Cal. 4th at 209
    . He
    “argued mitigating inferences from the guilt phase evidence
    presented by the prosecution,” and also that Ross was only
    twenty-one at the time of the murders, that Mark Howard
    was a gang member, that it was Evan Malett who pulled the
    trigger in the Taylor murders, and that Ross had proven he
    can behave in a confined environment like prison. 
    Id.
    at 209–10.
    ROSS V. DAVIS                       61
    Ross contends that the California Supreme Court’s
    consideration of defense counsel’s closing argument while
    reweighing the evidence was contrary to Strickland because
    it is axiomatic that “argument is not evidence.” But this is
    not quite what the California Supreme Court actually did—
    it did not consider counsel’s argument in a vacuum. Rather,
    the state court considered counsel’s argument to the extent
    he argued inferences legitimately drawn from the evidence.
    Lenoir “argued mitigating inferences from the guilt phase
    evidence presented by the prosecution” as well as mitigating
    inferences from the three items of evidence introduced by
    stipulation and judicial notice—Malett’s life sentence,
    Howards’ gang membership, and Ross’s relative youth and
    conformity during confinement. In re Ross, 
    10 Cal. 4th at
    209–10. Although argument is not evidence, it must be
    based on inferences properly drawn from the evidence. And
    drawing out those inferences in a way favorable to Ross was
    counsel’s duty. Here, unlike in Andrews, the California
    Supreme Court reweighed the evidence, including the
    reasonable inferences rationally drawn from it, as required
    by Strickland.
    For example, defense counsel argued, “You can
    reasonably infer that Mr. Ross behaved during the two years
    he was in prison [for the assault on Mark Howard]. There is
    nothing to show otherwise.” 
    Id. at 210
     (emphasis added).
    And he pointed out that the diligent prosecutor would have
    presented evidence to the contrary had it existed. From that,
    defense counsel drew the inference he believed the jury
    should make: “Some people cannot conform unless they are
    in a confined environment, and he has proven that he can do
    that.” 
    Id. at 211
    . The California Supreme Court weighed
    that evidence and those inferences against the hypothetical
    trial where the potential mitigation evidence had been
    introduced: “This argument, a potentially compelling one
    62                      ROSS V. DAVIS
    when the jury must decide whether the defendant should
    spend the rest of his natural life in a ‘confined environment,’
    could not have been made if counsel had produced the
    mitigating evidence suggested in this proceeding and
    triggered the rebuttal evidence that petitioner had a sustained
    juvenile petition ‘for brandishing a weapon based on
    threatening a probation camp cook with a large serving
    fork.’” 
    Id.
    Moreover, Ross cites no well-established Supreme Court
    precedent precluding consideration of closing argument
    when a reviewing court conducts the Strickland prejudice
    analysis. To the contrary, both the Supreme Court and our
    court have addressed defense counsel’s closing argument
    when conducting a Strickland prejudice analysis. See, e.g.,
    Williams, 
    529 U.S. at 369
     (noting that the bulk of defense
    counsel’s closing argument “was devoted to explaining that
    it was difficult to find a reason why the jury should spare
    [defendant’s] life” and ultimately concluding habeas relief
    was warranted); Yarborough v. Gentry, 
    540 U.S. 1
    , 4 (2003)
    (explaining how “tactical decisions in [counsel’s] closing
    presentation [are] particularly important because of the
    broad range of legitimate defense strategy at that stage” in
    denying habeas relief); Bell, 
    535 U.S. at 701
     (rejecting the
    argument that waiving closing argument and “counsel’s
    failure to advocate for life in closing necessarily left the jury
    with the impression that he deserved to die” in denying
    habeas relief); Andrews, 944 F.3d at 1101 (highlighting
    counsel’s “short, rambling closing statement” as part of the
    minimal mitigation case that warranted granting federal
    habeas relief); Avena, 932 F.3d at 1251 (discussing a defense
    closing argument that congratulated the jury on reaching the
    right decision in convicting their client).
    ROSS V. DAVIS                               63
    Ross next argues for the first time on appeal 7 that the
    California Supreme Court acted contrary to Strickland
    because it improperly applied a causal nexus test between
    the potential mitigation evidence and the home-invasion
    robbery murders. See In re Ross, 
    10 Cal. 4th at
    212–13.
    After reviewing the strong aggravating factors in this case—
    the three cold-blooded murders, including that of a man and
    his fourteen-year-old disabled son, hands tied behind one of
    their backs, and the rape of the sister of the third murder
    victim—the California Supreme Court did note “[a]lthough
    the additional mitigating evidence, had it been presented,
    might have evoked sympathy, there was no compelling
    connection between that evidence and the crimes of this
    case.” In re Ross, 
    10 Cal. 4th at 213
    . It explained that “[t]he
    crimes were gang-conducted robbery murders not sudden
    explosions of angry violence or psychopathic killings.” 
    Id.
    In Eddings v. Oklahoma, 
    455 U.S. 104
     (1982), the
    Supreme Court held that it was an Eighth Amendment
    violation to preclude the sentencing entity from considering
    mitigation evidence because it was not mitigating as a matter
    of law. There, the trial judge stated that, in “following the
    law,” he could not “consider the fact of this young man’s
    violent background,” meaning the mitigating evidence of
    Eddings’s violent physical abuse by his father. Eddings,
    7
    Although we generally do not consider an issue raised for the first
    time on appeal, we may address this issue when either (1) “review is
    necessary to prevent a miscarriage of justice or to preserve the integrity
    of the judicial process,” (2) “a new issue arises while appeal is pending
    because of a change in the law,” or (3) “the issue presented is purely one
    of law and either does not depend on the factual record developed below,
    or the pertinent record has been fully developed.” Bolker v. C.I.R., 
    760 F.2d 1039
    , 1042 (9th Cir. 1985) (citations omitted). We elect to consider
    the issue here to preserve the integrity of the judicial process and because
    the record is fully developed for our consideration.
    64                      ROSS V. DAVIS
    
    455 U.S. at 109
    . But, once again, this is not quite what the
    California Supreme Court did here. It did not refuse to
    consider the physical abuse of Ross by his stepfather Brown;
    it did consider it and concluded Ross’s abuse did evoke
    sympathy. In re Ross, 
    10 Cal. 4th at 195
    . However, the state
    court noted that all of the abuse had ended when Brown left
    the family when Ross was age twelve. 
    Id. at 208
    . And in
    stating that there was “no compelling connection between
    that evidence” and these crimes, the court was merely stating
    that the early childhood abuse Ross had suffered had failed
    to sufficiently explain why Ross had committed the heinous
    crimes of which the jury had just found him guilty,
    especially in light of the potential rebuttal that Ross has an
    extensive record consisting of gun-related juvenile offenses.
    For example, in Avena v. Chappell, we found that
    potential mitigating evidence that defense counsel failed to
    present prejudiced the defendant precisely because it
    explained to the jury why the brutal crimes were committed.
    For Avena, evidence of “habitual PCP use, as well as the
    effects the drug had on his demeanor” provided
    “considerable potential . . . to argue . . . [its] use contributed
    to [Avena’s] violent and erratic behavior on the night of the
    carjacking homicides.” Avena, 932 F.3d at 1252. Here, the
    potential mitigating evidence of abuse, while indisputably
    significant, sheds no light on why Ross would have
    committed the three cold-blooded murders and rapes, or why
    the jury should not impose the death penalty given the
    heinous nature of the crimes. See In re Ross, 
    10 Cal. 4th at
    212–13. We conclude that the California Supreme
    Court’s decision was not contrary to Strickland.
    2.
    The California Supreme Court’s decision denying
    Ross’s claim of ineffective assistance of counsel during the
    ROSS V. DAVIS                        65
    penalty phase for lack of prejudice was a reasonable
    application of Strickland. 
    28 U.S.C. § 2254
    (d)(1).
    To begin, we defer to the California Supreme Court’s
    finding that the additional mitigation evidence uncovered at
    the reference hearing was “substantial.” 
    Id. at 205
    . While
    growing up, Ross was abused extensively by his stepfather,
    and “[e]vidence of abuse inflicted as a child is especially
    mitigating.” Andrews, 944 F.3d at 1117; see also Summerlin
    v. Schiro, 
    427 F.3d 623
    , 635 (9th Cir. 2015) (en banc)
    (referring to family history and abuse as “classic mitigation
    evidence”). All fifteen available witnesses would have
    asked the jury for a life sentence instead of death, a plea for
    mercy that the jury should have heard. See Livaditis v.
    Davis, 
    933 F.3d 1036
    , 1048 (9th Cir. 2019).
    The California Supreme Court properly reweighed the
    old and new mitigating evidence against the existing
    aggravating evidence. “Courts considering additional
    evidence in post-conviction proceedings must ‘evaluate the
    totality of the available mitigation evidence—both that
    adduced at trial, and the evidence adduced in the habeas
    proceeding in reweighing it against the evidence in
    aggravation.’” Mann v. Ryan, 
    828 F.3d 1143
    , 1160 (9th Cir.
    2016) (en banc) (quoting Williams, 
    529 U.S. at
    397–98).
    When the state habeas record includes new factual
    allegations or evidence that the court reasonably finds
    subject it to a “potentially devastating rebuttal,” In re Ross,
    
    10 Cal. 4th at 205
    , the court may reasonably conclude that
    the mitigating evidence “is of questionable mitigating
    value.” Pinholster, 
    563 U.S. at 201
    .
    Here, the California Supreme Court recognized that
    Ross’s potential classic mitigating evidence—physical
    abuse and good character—did not cover Ross’s post-
    adolescent period following Gloria’s separation from Brown
    66                     ROSS V. DAVIS
    when Ross was twelve. And while substantial testimony
    painted Ross as a kind and nurturing person as a child and
    young adolescent, the California Supreme Court found that
    there was no evidence of Ross’s continuing good character.
    Indeed, the prosecutor introduced evidence that by the time
    Ross turned eighteen, he was a gang member who had
    already shot Mark Howard six times in the chest and torso
    over a dispute about a radio. The California Supreme Court
    questioned just how “effective it would be for the defense to
    present a parade of witnesses testifying about petitioner’s
    good qualities up to sometime around the age of twelve
    years, but necessarily leaving an obvious gap during his teen
    years.” In re Ross, 
    10 Cal. 4th at 208
    . Because the
    California Supreme Court recognized that practically all the
    mitigating evidence was “painfully limited” to a pre-
    adolescent Ross, 
    id.,
     the court reasonably concluded the jury
    would not have been swayed by it against imposing the death
    penalty in light of the potential rebuttal and impeachment
    evidence and the heinous circumstances of the murders.
    Had the potential mitigating evidence been admitted at
    trial, potentially damaging impeachment and rebuttal
    evidence would have been triggered, according to the
    California Supreme Court. See 
    id. at 205
    . This evidence
    was particularly devastating because it filled the gap from
    the time Brown stopped beating Ross at age twelve to his
    gang membership and shooting of Howard at age eighteen.
    Between the ages of twelve and eighteen, Ross developed an
    extensive juvenile record: four counts of robbery, three
    counts of burglary involving the theft of guns, and one count
    of brandishing a fork in a threatening manner at a cook while
    in custody. 
    Id. at 207
    . The California Supreme Court
    reasonably determined this evidence was admissible “to
    rebut evidence portraying [Ross] as a kind, protective, caring
    person.” 
    Id.
    ROSS V. DAVIS                          67
    Ross argues that this evidence may not have been
    admitted had counsel solely focused on his family
    background and the physical abuse he endured at the hands
    of Brown. But even assuming that defense counsel had
    found the good character evidence, but decided not to
    introduce it in mitigation, the California Supreme Court
    reasonably determined the testimony about the physical
    abuse itself was impeachable in two ways: by Ross’s
    mother’s prior statements and by Ross’s own prior
    statements. 
    Id. at 206
    . The state court reasonably found that
    the statements Gloria made to Ross’s probation officers
    highlighting how Ross’s problems only started after she
    separated from Brown and how Ross was “by far the worst”
    out of her six children and “show[ed] a great deal of
    resentment towards all types of people,” statements made
    closer in time to his juvenile crimes, would have undermined
    her trial testimony. And the facts that at the time of trial
    Gloria had reunited with Brown and that they were living
    together would surely have been elicited to question the fact
    and extent of any abuse Ross suffered. Ross’s own
    statements to a psychiatrist at the age of fifteen that he liked
    his stepfather Brown and was not abused at home further
    undermined the testimony about the abuse. 
    Id. at 200
    .
    Because this statement was closer in time to the alleged
    abuse, the court reasonably determined it carried more
    weight than the potential mitigation testimony would have
    carried. 
    Id.
     Considering that these statements and actions
    are logically inconsistent with the claimed abuse, the
    California Supreme Court reasonably concluded that the
    mitigating evidence of abuse would have been weakened in
    reweighing the mitigating evidence. 8
    8
    As the California Supreme Court itself noted, Ross could have
    countered this impeachment evidence with argument about how victim
    68                        ROSS V. DAVIS
    The California Supreme Court also found Ross’s
    argument that his defense counsel could “parse” the
    character evidence into discrete periods failed as a matter of
    law. It explained that the purpose of rebuttal at this stage
    was to present a “balanced picture of the defendant’s
    personality.” 
    Id. at 208
    . The court elaborated: “Evidence
    that petitioner was a good child, but committed various acts
    of misconduct as a teenager and then as an adult, presents a
    more balanced picture than evidence that petitioner was a
    good child, then later committed adult crimes, deleting
    accurate evidence of petitioner’s juvenile record.” 
    Id.
    at 208–09. It reasonably concluded, “[c]haracter evidence
    cannot be parsed so finely.” 
    Id. at 209
    .
    The circumstances of the murders, as well as the murders
    themselves, were aggravating factors. Ross “was convicted
    of three murders on two separate occasions, including the
    cold-blooded killing of a father and his fourteen-year-old
    [disabled] son, who were shot while lying on a bed, [the
    father] with his hands tied behind his back.” 
    Id. at 213
    . Ross
    personally twice raped the sister of the third murder victim,
    Michael Taylor. 
    Id.
     The state court judges used words such
    as “sadistic, unbelievably cruel, senseless,” and “cold-
    blooded” to describe the murders. In re Ross, 
    10 Cal. 4th at 213
    . Indeed, these facts “inspire little sympathy.” Andrews,
    944 F.3d at 1100; see also Cain v. Chappell, 
    870 F.3d 1003
    ,
    1021 (9th Cir. 2017) (“[I]n light of the aggravating
    circumstances involving the brutal murders of a couple in
    denial and inconsistent forms of behavior are common in abusive
    situations. See In re Ross, 
    10 Cal. 4th at 206
    . The court nevertheless
    reasoned that “petitioner’s own words, more contemporaneous to the
    alleged incidents than the later testimony of his relatives, would have
    made effective impeachment.” 
    Id.
     Under AEDPA, we must defer to this
    finding.
    ROSS V. DAVIS                       69
    their sixties, the thirteen blows administered to [the
    husband], the attempted rape of [the wife], and Cain’s prior
    violent acts, the state court’s denial of this claim was not
    unreasonable.”).
    The jury heard further aggravating evidence of Ross’s
    violence. Ross shot Mark Howard six times in the chest in
    a dispute over a radio, an act the prosecutor described as
    essentially “a[nother] murder where the victim, fortunately,
    did not die.” Based on the extent of the aggravating
    circumstances here, as well as the rebuttal evidence of
    juvenile crime, the California Supreme Court reasonably
    concluded that “even if [it assumed that] counsel would have
    presented the [mitigating] evidence, . . . after comparing the
    trial as it actually occurred with the trial as it would have
    been with the mitigating evidence, [] there was no
    prejudice.” In re Ross, 
    10 Cal. 4th at 213
    ; see Shinn, 141 S.
    Ct. at 524 (finding that because of the nature of the
    aggravating circumstances, “[p]erhaps the most probable
    reason for [the state court’s] no-prejudice determination is
    simply that the new mitigation evidence . . . did not create a
    substantial likelihood of a different sentencing outcome.”);
    see also Livaditis, 933 F.3d at 1050–51 (9th Cir. 2019)
    (finding the strength of aggravating evidence a factor in
    favor of denying the Strickland claim under AEDPA
    review).
    Ross disputes that the nature of the murders was so
    aggravating that the potential mitigation evidence could not
    have shifted the balance between life and death in the mind
    of at least one juror. But this argument is based on his
    rearguing the weight of the evidence as to his presence at the
    Hassan murders when the jury found that he was present and
    participated in the murders. Ross also argues that the fact he
    70                        ROSS V. DAVIS
    was not the triggerman 9 minimizes his role in the murders.
    Yet the jury had just convicted him of the three heinous
    murders, robbery, and rape. After carefully considering all
    of the mitigating and aggravating evidence introduced at
    trial—including Ross’s conduct during the trial, the potential
    mitigating evidence, and the potential impeachment and
    rebuttal evidence that could have been introduced—the
    California Supreme Court concluded that a sentence less
    than death was not reasonably probable. We cannot say that
    the California Supreme Court’s conclusion was
    unreasonable under all the circumstances presented here.
    VI.
    Certainly we would not find it unreasonable had the
    California Supreme Court determined Ross was prejudiced
    by counsel’s deficient performance. Even the State agreed
    that “the [California Supreme Court] certainly could have
    decided the matter differently.” But because the California
    Supreme Court’s conclusion “was premised on logic and
    reason,” it “cannot be fairly called unreasonable,” and thus
    should not be disturbed. On this record, habeas relief cannot
    be granted.
    For the reasons stated herein, we AFFIRM the decision
    of the district court.
    9
    The record is inconclusive on who actually fired the gun for all
    three murders, meaning it is entirely possible that Ross was indeed the
    shooter. However, no evidence established that fact and the prosecution
    conceded it likely did not prove that Ross was the shooter beyond a
    reasonable doubt.