In re Champion , 58 Cal. 4th 965 ( 2014 )


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  • Filed 4/14/14
    IN THE SUPREME COURT OF CALIFORNIA
    In re STEVE ALLEN CHAMPION          )
    )
    on Habeas Corpus.                   )                               S065575
    )
    ____________________________________)
    Petitioner Steve Allen Champion seeks relief on habeas corpus from the
    judgment of death entered against him in 1982 in Los Angeles Superior Court,
    case No. A365075. On direct appeal, we affirmed that judgment and a judgment
    of death against his codefendant, Craig Anthony Ross. (People v. Champion
    (1995) 
    9 Cal.4th 879
     (Champion).) In 2002, we issued an order to show cause
    based on petitioner‟s allegation, in a petition for writ of habeas corpus, that his
    trial attorney (Ronald Skyers, now a Los Angeles Superior Court Judge)
    ineffectively represented him at the penalty phase of trial. We appointed the
    Honorable Francisco P. Briseño, Judge of the Orange County Superior Court, as
    referee, and directed him to take evidence and make findings of fact. Judge
    Briseño has done so. Based on his findings, we deny relief.
    I. TRIAL EVIDENCE
    Below is a summary of the evidence at petitioner‟s capital trial.
    Elizabeth Moncrief, a nurse caring for a neighbor, saw four men forcibly
    enter the home of Bobby and Mercie Hassan on December 12, 1980. Later that
    day, police found the bodies of Bobby Hassan (an unemployed carpenter who sold
    marijuana) and his 14-year-old son Eric (described by his stepmother Mercie as
    1
    “handicapped”) on a waterbed in the home. Bobby‟s hands were tied behind his
    back; each victim had been shot once in the head. Items were missing from the
    house. At trial, Moncrief identified petitioner and codefendant Craig Anthony
    Ross as two of the men she had seen entering the Hassan home. On cross-
    examination, Moncrief admitted that she had previously identified two other men,
    neither of whom had any connection to petitioner, as two of the intruders.
    (Champion, 
    supra,
     9 Cal.4th at pp. 898-899.)
    When arrested a month after the two murders, petitioner was wearing a ring
    and a necklace bearing a charm with the king of hearts. Bobby Hassan‟s wife,
    Mercie, testified that the ring and the necklace had belonged to her husband.
    (Champion, 
    supra,
     9 Cal.4th at p. 899.) The prosecution introduced a tape
    recording of a conversation between petitioner and codefendant Ross in the bus
    transporting them between the court and the jail after their arrest for the murders.
    On the bus, the two men spoke briefly of a waterbed; at trial, the prosecution
    argued that they were referring to the waterbed on which the two Hassans were
    killed. (Champion, supra, 9 Cal.4th at pp. 909-910.)
    Both Hassans were shot in the back of the head with a .357-caliber bullet
    with rifling characteristics typical of Colt revolvers. Photographs found in
    petitioner‟s home showed petitioner and codefendant Ross each holding a Colt
    revolver that was either .38- or .357-caliber. Ross‟s fingerprints were found on
    Christmas wrapping paper and a white cardboard box at the Hassan home.
    (Champion, supra, 9 Cal.4th at pp. 899-900.)
    The prosecution also introduced evidence of crimes committed at the home
    of Cora, Mary, and Michael Taylor, who lived eight blocks from the Hassans. On
    December 27, 1980, two weeks after the murder of the two Hassans, three Black
    men invaded the Taylor house looking for drugs, and a fourth man (apparently a
    lookout) came to the door but did not enter. The men fatally shot Michael (who,
    2
    like Bobby Hassan, was a marijuana dealer) and one of the men raped Mary.
    Codefendant Ross‟s fingerprints were found at the scene. (Champion, 
    supra,
     9
    Cal.4th at pp. 900-901.)
    Later that same night, a Los Angeles County Sheriff‟s deputy tried to stop a
    speeding brown Buick automobile. When the car struck a curb and came to a halt
    near petitioner‟s house, the car‟s occupants (four Black males) ran away, but a
    sheriff‟s deputy found Jerome Evan Mallet (Evan Mallet or Mallet) hiding in the
    back yard of petitioner‟s home. In the car, the deputy found a tape player and a
    photograph album stolen from the Taylors and a .357-caliber revolver stolen from
    the Hassan home. According to a ballistics expert, the bullet that killed Michael
    Taylor could have been fired by the revolver, which contained two live rounds and
    an empty shell casing and smelled as if it had recently been fired. (Champion,
    
    supra,
     9 Cal.4th at pp. 900-901.)
    At trial, Cora and Mary Taylor identified codefendant Ross and Evan Mallet
    as two of the men who had invaded their home and murdered Michael Taylor, and
    Mary identified Ross as the one who had raped her. Cora also identified petitioner
    as one of the perpetrators. Because the Taylors had not previously identified
    petitioner, he had not been charged with the offenses committed at the Taylor
    home. (Champion, 
    supra,
     9 Cal.4th at pp. 900-901.)
    The prosecution also introduced evidence that a month before the two
    Hassans were murdered, the body of Teheran Jefferson, a third marijuana dealer
    who lived in the same block as the Hassans, was found in his home. The upper
    torso of Jefferson‟s body was on his bed, while his legs and feet were on the floor.
    Like Bobby Hassan, his hands were tied behind his back, and (like the Hassans) he
    had been shot once in the head with a bullet of .38- or .357-caliber. The
    prosecution produced no evidence (apart from the similarities of the crimes)
    3
    linking either petitioner or codefendant Ross to Jefferson‟s death. (Champion,
    supra, 9 Cal.4th at p. 917.)
    The prosecutor argued to the jury that all of the murders described above
    were committed by the Raymond Avenue Crips, a criminal street gang operating
    in the Los Angeles neighborhood where the murders occurred, as part of a plan to
    kill and rob drug dealers operating on their turf. The prosecution introduced
    evidence that petitioner, codefendant Ross, and Mallet were members of that gang,
    and that the brown Buick car tied to the Hassan and Taylor killings was owned by
    the stepfather of gang members Marcus and Michael Player. (Champion, supra, 9
    Cal.4th at pp. 919-921.)
    Petitioner presented an alibi defense, testifying that on the morning that
    Bobby and Eric Hassan were murdered, he and his brothers, Reginald and Louis,
    picked up his paycheck from Prompt Service, a “temporary personnel” agency that
    had employed him. He then went home, where he spent the afternoon. His
    brother Reginald and his mother Azell corroborated his account. (Champion,
    supra, 9 Cal.4th at p. 902.)
    The jury convicted both petitioner and codefendant Ross of burglarizing the
    Hassan home and of robbing and murdering Bobby and Eric Hassan. As to each
    defendant, the jury found true special circumstance allegations of multiple murder,
    burglary murder, and robbery murder. The jury also convicted codefendant Ross
    of numerous felonies, including murder, committed at the Taylor home. In a
    separate trial held before that of petitioner and codefendant Ross, Evan Mallet was
    convicted of murder and other felonies at the Taylor home.
    At the penalty phase, the prosecution presented evidence that in November
    1977, petitioner and seven other youths robbed Vincent Verkuilen, Jerry Stanger,
    and Laura Surgot at gunpoint at a Greyhound Bus depot in West Covina. The
    prosecution also presented evidence that in September 1978, petitioner and four
    4
    other youths approached Jose Bustos and his wife in a park and took their radio.
    When Bustos tried to retrieve it, petitioner kicked him, hit him on the head with a
    knife, and cut his finger with a switchblade. Petitioner was a minor when he
    committed these two offenses. As a result of the second offense he was
    committed to what was then called the California Youth Authority (CYA), now
    the Division of Juvenile Facilities of the California Department of Corrections and
    Rehabilitation, from which he was released on parole less than two months before
    committing the murders in this case. Petitioner was 18 years old at the time of
    those murders.
    Petitioner‟s trial attorney, Ronald Skyers, called two penalty phase
    witnesses: Azell Champion (petitioner‟s mother) and Thomas Crawford (his CYA
    parole officer). Petitioner‟s mother testified that on the day petitioner was arrested
    for the two murders in this case, he was to start work at Gompers Junior High
    School in Los Angeles. Parole Officer Crawford said petitioner was cooperative
    and maintained satisfactory contact during the three months that he was on parole.
    (Champion, supra, 9 Cal.4th at p. 904.)
    II. ORDER OF REFERENCE
    We asked the referee to take evidence and make findings of facts on these
    questions:
    “1. What actions did petitioner‟s trial counsel take to investigate potential
    evidence that could have been presented in mitigation at the penalty phase of
    petitioner‟s capital trial? What were the results of that investigation?
    “2. What additional mitigating evidence, if any, could petitioner have
    presented at the penalty phase? How credible was this evidence?
    “3. What investigative steps, if any, would have led to this additional
    evidence? In 1982, when petitioner‟s case was tried, would a reasonably
    5
    competent attorney have tried to obtain such evidence and to present it at the
    penalty phase?
    “4. What circumstances, if any, weighed against the investigation or
    presentation of this additional evidence? 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 this evidence?
    “5. Did petitioner do or say anything to hinder or prevent the investigation
    or presentation of mitigating evidence at the penalty phase, or did he ask that any
    such evidence not be presented? If so, what did he do or say?”
    Below, we summarize the referee‟s findings regarding these questions, and
    we address the exceptions taken by the parties to those findings.
    A. What actions did petitioner’s trial counsel take to investigate
    potential evidence that could have been presented in mitigation at
    the penalty phase of petitioner’s capital trial? What were the
    results of that investigation?
    1. Referee’s findings
    The referee‟s findings on this question pertained to three categories of
    potentially mitigating evidence: (1) evidence pertaining to the charged offenses
    (the murders of Bobby and Eric Hassan); (2) evidence responding to the
    prosecution‟s aggravating evidence, which consisted of the two felonies (robbery
    and aggravated assault) petitioner committed as a juvenile, the crimes committed
    at the Taylor home (hereafter the Taylor crimes), and the murder of Teheran
    Jefferson;1 and (3) evidence pertaining to petitioner‟s social history, development,
    and mental functioning.
    1      The evidence pertaining to the Taylor crimes and the murder of Teheran
    Jefferson was presented at the guilt phase, not the penalty phase. But the trial
    court‟s instructions permitted the jury to consider, at the penalty phase, evidence
    (Footnote continued on next page.)
    6
    With regard to the first category of potentially mitigating evidence —
    evidence pertaining to the murders of Bobby and Eric Hassan — the referee found
    that Defense Counsel Skyers had read the discovery provided by the prosecution,
    visited the crime scene as well as petitioner‟s home and Helen Keller Park (which
    was across the street from the Hassans‟ home and was the scene of certain events
    relevant to the Taylor crimes, discussed in pt. II.B.2.a., post), and spoke with
    petitioner and those members of petitioner‟s family who were potential witnesses.
    Skyers did not independently investigate or interview the prosecution witnesses.
    Skyers, the referee said, knew that the prosecutor had no evidence that it was
    petitioner who shot the Hassans, but he also was aware that the egregious nature of
    the murders — the execution-style shooting of a man and his 14-year-old son —
    would place, in the referee‟s words, “an almost insurmountable burden on any
    reasonable trial attorney in identifying and presenting . . . mitigation.”
    As to the second category of potentially mitigating evidence — evidence
    refuting the prosecution‟s aggravating evidence — the testimony at the posttrial
    reference hearing focused primarily on the Taylor crimes. (See pp. 2-3, ante.) As
    previously explained (ibid.), petitioner was not charged with those crimes, but
    codefendant Ross was, and at the guilt phase of trial prosecution witness Cora
    Taylor identified petitioner as one of the perpetrators. The referee found that
    Defense Counsel Skyers had reviewed the discovery he received from the
    prosecution pertaining to those crimes, but that he conducted no independent
    investigation to determine whether he could present evidence that petitioner was
    (Footnote continued from previous page.)
    of aggravating circumstances that had been presented at the guilt phase. (See
    Champion, 
    supra,
     9 Cal.4th at p. 946.)
    7
    not one of the perpetrators. The referee noted that Skyers was unsure whether he
    had even asked petitioner about an alibi. Skyers did not attend the trial of Evan
    Mallet, who was charged with the Taylor crimes and whose trial occurred before
    that of petitioner and Ross, nor did he read the transcripts of Mallet‟s trial.
    As to the murder of Teheran Jefferson, the referee found that Defense
    Counsel Skyers had read the police reports provided by the prosecution and visited
    the crime scene, but that he did no additional investigation (such as contacting
    witnesses identified in the police reports, conducting ballistics tests on the bullet
    found in Jefferson‟s body, and investigating the extent to which the Jefferson
    murder resembled the murders of the two Hassans and of Michael Taylor).
    With respect to the two felonies petitioner committed as a juvenile, the
    referee found that Skyers had read the discovery furnished by the prosecution, and
    the referee noted that the “main mitigation” pertaining to these offenses was
    “petitioner‟s age and lack of maturity.”
    Turning to the third category of potentially mitigating evidence — evidence
    pertaining to petitioner‟s social history, development, and mental functioning —
    the referee found that Defense Counsel Skyers had reviewed petitioner‟s CYA
    records, which the referee described as documenting “petitioner‟s conduct within a
    structured setting.” The records contained reports by two psychologists and two
    psychiatrists, all of whom concluded that petitioner had no mental illness, defect,
    or disorder. Skyers also reviewed a report jointly prepared by two psychiatrists
    (Dr. Seymour Pollack and Dr. Lillian Imperi) appointed by the trial court at the
    request of Skyers‟s predecessor, Homer Mason, to evaluate petitioner‟s mental
    health. Drs. Pollack and Imperi, like the mental health professionals at CYA,
    found no evidence that petitioner suffered from any mental illness, defect, or
    disorder.
    8
    Defense Counsel Skyers, the referee found, had interviewed petitioner and
    visited his home, where Skyers talked to petitioner‟s mother, older sisters, and one
    of his two older brothers about petitioner‟s home life, childhood, and other family
    matters. Skyers did not interview petitioner‟s older brother Lewis or his younger
    siblings, nor did he contact members of petitioner‟s extended family who lived
    nearby. The family did not tell Skyers that petitioner had suffered fetal abuse, an
    alleged 1968 head injury, head trauma inflicted by older brothers, and extreme
    family poverty, topics that family members testified to at the posttrial reference
    hearing.
    The referee found that Defense Counsel Skyers “did not adequately conduct
    a separate, independent [penalty] investigation”; that he “failed to retain a penalty
    phase investigator”; that he “did not interview all potential mitigation witnesses
    including petitioner‟s teachers, friends, CYA staff, CYA doctors, fellow gang
    members or law enforcement personnel”; and that he “did not assemble all
    documents” pertaining to the penalty phase, including “school records and . . .
    [Evan] Mallet‟s trial transcripts.”
    The Attorney General does not dispute the referee‟s findings. Petitioner,
    however, takes exception to two findings that he alleges the referee made, which
    we address below.
    2. Exceptions to the referee’s findings
    First, petitioner asserts: “There is no basis for the referee‟s finding that
    [Defense Counsel Ronald] Skyers obtained a penalty phase evaluation from
    [psychiatrist Seymour] Pollack.” Petitioner does not give a page citation for any
    such finding in the referee‟s report, and we cannot locate any such finding. The
    referee correctly stated: “The record is clear that Skyers did not specifically ask
    9
    Dr. Pollack to conduct a social history evaluation of petitioner‟s life for the
    specific purpose of developing potential penalty phase evidence.”
    Second, petitioner takes exception to the referee‟s finding that Defense
    Counsel Skyers reviewed the mental health evaluations of petitioner prepared at
    CYA when petitioner was incarcerated there. Petitioner points out that Skyers
    testified at the posttrial reference hearing that he could not remember whether he
    had reviewed these evaluations, and that Skyers‟s case file did not contain copies
    of the evaluations. Skyers‟s lack of recall is not surprising, because the hearing
    occurred more than two decades after petitioner‟s capital trial. But materials in
    Skyers‟s case file indicate that he did review the evaluations: A file note states
    that Skyers spoke to a person at the parole office who said that Skyers needed
    authorization from petitioner to see petitioner‟s CYA file, the file contains an
    authorization petitioner signed three days after the date of the note, and another
    file note gives the address of the CYA parole office where a review logically
    would have occurred. Based on this circumstantial evidence, we agree with the
    referee that Skyers most likely reviewed the CYA mental health evaluations.
    B. What additional mitigating evidence, if any, could petitioner have
    presented at the penalty phase? How credible was this evidence?
    1. Referee’s findings
    Regarding the circumstances surrounding the charged murders of Bobby
    and Eric Hassan, the referee found that petitioner failed to show that Defense
    Counsel Skyers could have presented any additional mitigating evidence. The
    referee also found that petitioner produced no mitigating evidence that the defense
    could have presented pertaining to the murder of Teheran Jefferson (evidence of
    which was presented by the prosecution at the guilt phase of petitioner‟s capital
    trial), or to the two felonies petitioner committed as a juvenile (evidence of which
    was presented by the prosecution at the penalty phase).
    10
    With respect to the Taylor crimes, the referee concluded that the defense
    could have presented alibi evidence tending to show that petitioner was not at the
    Taylor home on the night of the crimes. (We summarize this evidence in pt.
    II.B.2.a., post.) But the referee also found that the witnesses who testified to this
    alibi at the posttrial reference hearing were, like petitioner, members of the
    Raymond Avenue Crips, a criminal street gang. Their testimony, the referee said,
    was “inconsistent with their own declarations, with each other and with
    petitioner‟s own trial testimony,” and was “not credible.” Presentation of such
    alibi evidence at the penalty phase, the referee concluded, would not have assisted
    petitioner, as it would have confirmed petitioner‟s gang membership (which
    petitioner had denied in his guilt phase testimony) and his close association with
    codefendant Ross, whose guilt of the Taylor crimes was overwhelmingly shown.
    With respect to petitioner‟s social history, development, and mental
    functioning, petitioner presented evidence at the posttrial reference hearing that he
    suffered from brain damage, that he was traumatized by the death of a man who
    acted as a father figure toward him, that he performed poorly in school, that he
    was physically abused by various family members, that he grew up in
    impoverished circumstances, that he was amenable to rehabilitation and
    institutional adjustment, and that he was loved by his family and friends. As
    explained below, the referee found that some of this evidence was credible but
    some was not.
    With respect to petitioner‟s allegation that Defense Counsel Skyers could
    have presented evidence of petitioner‟s brain damage, the referee found the claim
    “not supportable.” The referee noted that two psychologists and two psychiatrists
    at CYA, and two psychiatrists retained by Homer Mason (Defense Counsel
    Skyers‟s predecessor as petitioner‟s trial attorney), and two mental health experts
    (a clinical psychologist and a forensic psychiatrist) who testified for the
    11
    prosecution at the posttrial reference hearing all found no evidence that petitioner
    was neuropsychologically impaired. Although petitioner claimed he could have
    suffered brain damage as a result of alleged fetal abuse, a traffic accident, or
    beatings allegedly inflicted by his older brothers, the referee found that petitioner
    did not suffer brain damage as a result of any of these events. The referee further
    found that, in view of the mental health examinations described above, all of
    which found no evidence of psychological impairment, Defense Counsel Skyers
    “did not have any reason to order any additional evaluations,” and “no trial
    attorney could be faulted for not asking for further testing or concluding that no
    mitigating evidence existed at the time of trial as to petitioner‟s mental status.”
    With regard to petitioner‟s performance in school, the referee found that
    records from petitioner‟s school and from CYA showed that petitioner had “a low
    IQ, low intellectual functioning, reading and learning difficulties, attention
    deficits, a flat affect, deficiency in ability to conceptualize, low self-esteem,
    impulsiveness and a bad temper.” This evidence, the referee found, was “credible
    and available at time of trial.”
    As to the economic circumstances of petitioner‟s family, the referee
    rejected as lacking in credibility the evidence presented by petitioner that he grew
    up in extreme poverty, that he suffered from malnutrition and deprivation of
    childhood necessities, and that he was beaten by his older brothers. The referee
    found, however, that when petitioner‟s mother was working, “her absence from
    the home resulted in her inability to provide proper care, guidance, and
    supervision to petitioner.”
    With respect to petitioner‟s family and upbringing, the referee found that
    petitioner‟s biological father was physically abusive, but that he abandoned the
    family before petitioner was born. Petitioner‟s mother soon became romantically
    involved with Gerald Trabue, Sr., who was the primary father figure in petitioner‟s
    12
    life from the time of his birth until he was six years old, when Trabue was killed in
    a traffic accident. Trabue, the referee found, was a “wonderful person and
    provider” and his death “had a devastating impact on petitioner‟s family”:
    Petitioner‟s mother became depressed and the family temporarily experienced
    “major financial difficulties.” Trabue‟s death “adversely impacted” petitioner,
    who “did not have another father figure afterwards.” These matters, the referee
    found, could have been presented by counsel had it not been for the failure of
    members of petitioner‟s family to disclose them to Defense Counsel Skyers.
    With respect to petitioner‟s amenability to rehabilitation and institutional
    adjustment, the referee found that the evidence was mixed: Some CYA reports
    said that petitioner had complied with CYA rules and regulations, did well in his
    classes, was respectful to staff, and performed well in a structured setting. But the
    referee found that petitioner‟s participation in the murders of Bobby and Eric
    Hassan less than two months after his release from CYA “nullify this mitigation,”
    and other CYA reports mentioned incidents of violent conduct while petitioner
    was at CYA.
    With respect to love and support from family and friends, the referee found
    that the testimony of petitioner‟s mother, while lacking credibility in many
    respects, indicated her love and affection for petitioner, and that at the trial‟s
    penalty phase Defense Counsel Skyers should have called her to testify about her
    feelings for petitioner. The referee also found that other family members and
    childhood friend Gary Jones, had they been called as witnesses at trial, could have
    credibly testified that they loved and cared for petitioner.
    The Attorney General does not dispute the referee‟s findings. Petitioner
    takes exception to 11 findings. We divide his exceptions into two categories.
    First, we address his exceptions pertaining to the referee‟s findings regarding
    mitigating evidence that might have been presented to counter the prosecution‟s
    13
    aggravating evidence (the murders of Bobby and Eric Hassan, the Taylor crimes,
    the murder of Teheran Jefferson, and the crimes committed by petitioner as a
    minor). Second, we consider petitioner‟s exceptions pertaining to the referee‟s
    findings regarding mitigating evidence pertaining to petitioner‟s social history,
    development, and mental functioning.
    2. Exceptions to referee findings pertaining to the prosecution’s
    aggravating evidence
    a. “The reference court erred in finding petitioner’s lay witnesses
    not credible.”
    At the posttrial reference hearing, petitioner presented alibi evidence tending
    to show that he did not commit the Taylor crimes, but the referee found that
    crucial alibi witnesses were not credible. Petitioner challenges this finding. To
    evaluate his claim, we review the pertinent evidence presented at petitioner‟s
    capital trial, after which we summarize the alibi evidence presented at the
    reference hearing.
    Between 11:00 p.m. and midnight on December 27, 1980, three Black males
    invaded the Taylor home looking for drugs, and a fourth Black male (apparently a
    lookout) came to the door but did not enter. The men ransacked the home, stole a
    tape player and a photograph album, and fatally shot Michael Taylor. One of the
    men raped Mary Taylor.
    Shortly after the murder, a Los Angeles County Sheriff‟s deputy tried to stop
    four Black males in a brown Buick car that did not have its headlights on and was
    near Helen Keller Park, within half a mile of the Taylor home. The Buick took off
    at high speed, struck a curb, and came to a halt near petitioner‟s home; its
    occupants ran away. In the car, deputies found a tape player and a photograph
    album stolen from the Taylor apartment, as well as a revolver stolen from the
    Hassan home that, a prosecution expert concluded, probably fired the bullet that
    14
    killed Michael Taylor. In the back yard of petitioner‟s home, the deputies found
    Evan Mallet, who was later identified as one of the perpetrators of the Taylor
    crimes. Thus, it is likely that the occupants of the brown Buick committed those
    crimes.
    Petitioner testified at the guilt phase of his capital trial, denying that he was
    one of the men who murdered Bobby and Eric Hassan, but on direct examination
    he did not mention the Taylor crimes. On cross-examination, the prosecutor asked
    petitioner where he was on the night of those crimes. Petitioner said he was home
    between 10:00 and 11:00 p.m., but that he left between 11:00 and 11:30 p.m. and
    stayed out until after midnight. He said that during that time (but after the crash of
    the brown Buick) he was detained by sheriff‟s deputies. Petitioner‟s mother, when
    asked on cross-examination where petitioner was that night, said he was at home.
    At the posttrial reference hearing, petitioner‟s alibi witnesses — Marcus
    Player, Wayne Harris, and Earl Bogans — testified that petitioner was playing
    basketball in Helen Keller Park at the time of the Taylor crimes. Their testimony
    also tended to implicate Robert Simms rather than petitioner as the one who, along
    with Craig Ross and Evan Mallet, committed the Taylor crimes. We summarize
    the alibi witnesses‟ testimony below.
    Marcus Player testified that on the night in question he was at his fiancée‟s
    house, but between 10:00 and 11:00 p.m. he walked to a liquor store to buy some
    orange juice or milk. On his way, he saw a group of people, including petitioner
    and Wayne Harris (Player‟s cousin), at the basketball court in Helen Keller Park,
    and he spoke with them for half an hour. He then went to the liquor store to make
    his purchase. On the way back to his fiancée‟s house, sheriff‟s deputies detained
    him. Petitioner and Harris were not with him at the time. While Player was being
    detained, a brown Buick that Player recognized as belonging to his stepfather
    entered the park, and the deputies left him to chase it.
    15
    Hearing the Buick crash, Player, joined by petitioner and Harris, went to see
    what had happened. Sheriff‟s deputies then detained and questioned them. Player
    told the deputies that the car belonged to his stepfather and that he had last seen it
    being driven by his brother Michael. The deputies ordered Player, petitioner, and
    Harris to walk to the location of another patrol car. While they were walking
    there, they were joined by a youth that Player knew only by the name “Lil Owl.”
    The deputies at the second car ordered them to sit on a curb for approximately half
    an hour, during which time a police car came by and shone a spotlight on them.
    Eventually, the deputies took Lil Owl into custody and allowed Player, Harris, and
    petitioner to go to petitioner‟s home.
    Wayne Harris testified that on the night in question he and petitioner, along
    with a dozen other youths, played basketball until about 10:30 p.m., when they left
    to go to the store. As they walked, sheriff‟s deputies arrived at the park and
    detained several youths, not including petitioner and Harris.2 While the detentions
    were occurring, a brown Buick came into the park, then sped away, apparently
    after its occupants saw the deputies. The deputies gave chase. Harris, petitioner,
    and Marcus Player then started walking west on 126th Street, noticing that the
    Buick, which Harris recognized as belonging to the Player family, had crashed.
    Shortly thereafter, sheriffs‟ deputies detained the trio and ordered them to walk to
    another sheriff‟s department vehicle. As they walked, Lil Owl joined them. When
    they reached the second sheriff‟s vehicle, the deputies questioned the youths and
    checked their pulse rates by placing a hand on each of their chests. Eventually
    2      Harris acknowledged that he had signed a 1997 declaration stating he,
    petitioner, and Marcus Player, had been detained in the park by the deputies, and
    held for four hours, but he did not recall making the statements attributed to him in
    the declaration.
    16
    they took Lil Owl away and allowed petitioner, Player, and Harris to go to
    petitioner‟s home.
    Earl Bogans testified that on the night in question he arrived at Helen Keller
    Park between 7:00 and 7:30 p.m. There, he played basketball with petitioner,
    Marcus Player, and other youths for about 90 minutes, after which they sat in the
    parking lot smoking marijuana. About 10:00 p.m., two patrol cars drove up. The
    sheriff‟s deputies inside told the youths to lie on their stomachs. Suddenly a
    brown car entered the parking lot and quickly backed out again, and the deputies
    left to chase it. Bogans then went home.
    Sheriff‟s reports prepared at the time of the murder and testimony of sheriff‟s
    deputies at the posttrial reference hearing corroborated parts of the testimony of
    Player, Harris, and Bogans. According to the reports and testimony, sheriff‟s
    patrol cars went to Helen Keller Park shortly before midnight on the night of the
    Taylor crimes, responding to a call of a gang-related disturbance. There, the
    deputies detained four Black males. When the chase of the brown Buick began,
    the deputies left the park and joined in the chase. After the Buick crashed,
    deputies set up a perimeter to try to contain the Buick‟s passengers within a four-
    block area around the crash site.
    At 12:30 a.m., petitioner, Marcus Player, and Wayne Harris were detained by
    sheriff‟s deputies when they walked into the containment area. The deputies filled
    out field interrogation cards and told the three to walk to another command post in
    the containment area and identify themselves. When they arrived at the second
    post, they were accompanied by a 16-year-old youth who falsely identified himself
    as “James Taylor” (apparently Lil Owl). There, sheriff‟s deputies again detained
    them and filled out field identification cards, after which the deputies released
    petitioner, Player, and Harris. Because “Taylor” had joined the other three in the
    containment area and because his appearance and clothing closely resembled one
    17
    of the four Black males former Deputy Sheriff (now Attorney) Theodore Naimy
    had seen in the brown Buick, he was taken to a sheriff‟s station where deputies
    determined that his true name was Robert Simms. Simms was eventually released
    without being charged.
    But the deputies‟ reports and testimony neither confirmed nor disproved the
    testimony of Player, Harris, and Bogans that petitioner was in Helen Keller Park at
    the time of the Taylor crimes. A report prepared by Sergeant Owen Tong listed
    the names of the youths who were being detained in the park by the deputies when
    the chase of the brown Buick began; the list included Player and Bogans, but not
    petitioner. Thus, Player, Harris, and Bogans were the only witnesses whose
    testimony at the posttrial reference hearing gave petitioner an alibi for the Taylor
    crimes. But these three witnesses all were members of the Raymond Avenue
    Crips, as petitioner was.
    At the time of the posttrial reference hearing, both Player and Bogans were in
    prison: Player had been convicted of first degree murder, and Bogans had been
    convicted of robbing an armored car. Harris was not in custody, but he had
    convictions for robbery and kidnapping. Bogans also had shown a willingness to
    commit perjury on behalf of a fellow gang member. He admitted that after Evan
    Mallet was convicted of murdering Michael Taylor, Mallet telephoned Bogans and
    said he was sending Bogans a declaration that could help Mallet get out of jail. In
    the mail, Bogans received a blank declaration form that he signed and returned to
    Mallet, allowing Mallet to write whatever he liked in the declaration.
    The referee found that the alibi testimony of Player, Harris, and Bogans was
    not credible. Petitioner takes exception to this finding. He argues that Marcus
    Player “had no reason to lie for petitioner because, thinking petitioner only faced
    the Hassan charges, he did not realize the importance of his information to
    petitioner‟s defense.” Petitioner acknowledges that the testimony of the three alibi
    18
    witnesses was inconsistent in certain respects; he argues, however, that such
    discrepancies do not show a lack of credibility, asserting that the discrepancies are
    most likely attributable to the circumstance that the posttrial reference hearing was
    held decades after the events in question.
    Because the referee had an opportunity to observe the demeanor of Player,
    Harris, and Bogans when they testified, we give “great weight” to his
    determination that their testimony lacked credibility. (In re Price (2011) 
    51 Cal.4th 547
    , 559.) Moreover, their credibility is suspect because all three were
    members of petitioner‟s gang — and thus had a substantial motive to give
    testimony that would assist petitioner — and because all three had been convicted
    of very serious crimes that reflect adversely on their credibility. Furthermore,
    their reference hearing testimony and petitioner‟s testimony at trial differed in
    several significant respects: (1) Petitioner testified that he was at home most of
    the evening and did not leave before 11:00 p.m., whereas Harris, Bogans, and
    Taylor testified that he was playing basketball in Helen Keller Park during the
    time petitioner claimed to be at home; (2) petitioner denied that he was a member
    of the Raymond Avenue Crips, whereas Harris and Bogans said he was in the
    gang; (3) petitioner and Harris denied that they were detained by sheriff‟s deputies
    in Helen Keller Park just before the brown Buick entered the park, whereas
    Bogans said they were detained. For all of these reasons, substantial evidence
    supports the referee‟s finding that the witnesses were not credible.
    b. “The referee erred in finding that Marcus Player would have
    been unavailable to Skyers in support of petitioner’s defense
    against the allegation that he was involved in the Taylor
    Murder.”
    At the posttrial reference hearing, Marcus Player gave alibi testimony on
    petitioner‟s behalf. (See pt. II.B.1.a., ante.) The referee found, however, that
    Player “would not have cooperated with trial counsel in any effort to develop and
    19
    present an alibi through his testimony,” and that if Player had been called to testify
    at petitioner‟s capital trial, he would have invoked his privilege against self-
    incrimination to avoid prosecution as an accessory after the fact, based on his
    efforts to assist codefendant Craig Ross in evading arrest. The referee noted that
    at the time of petitioner‟s trial, Player was awaiting trial on an unrelated charge of
    murder, of which he was later convicted.
    Petitioner takes exception to the referee‟s finding. He notes that Player was
    not arrested until more than four months after Defense Counsel Skyers began his
    representation of petitioner, so Skyers could have spoken to Player before his
    arrest. Moreover, petitioner notes, Player testified at the posttrial reference
    hearing “that he was not fearful of a perjury charge because he had nothing to do
    with the Taylor crimes.” But Player also testified at the reference hearing that if
    he had been contacted by an attorney representing petitioner at the time of
    petitioner‟s trial he would not have spoken to the attorney, and that he would not
    have willingly testified at petitioner‟s trial. Based on this testimony, we agree
    with the referee‟s finding.
    c. “The referee errs in failing to find that Simms’s fingerprint
    would have been available at the time of petitioner’s trial.”
    As previously noted (see pt. I., ante), Cora and Mary Taylor testified at
    petitioner‟s capital trial that three men invaded their home on the night of
    December 27, 1980, and that the men raped Mary and fatally shot Michael Taylor
    (Cora‟s son and Mary‟s brother). At the posttrial reference hearing, petitioner
    attempted to show that Defense Counsel Skyers should have discovered and
    presented evidence that the three men were codefendant Craig Ross, Evan Mallet,
    and Robert Simms, and thus that petitioner could not have been one of the men.
    Simms, it will be recalled (see pt. II.B.2.a, ante), was detained by sheriff‟s
    deputies on the night of the murder when he, accompanied by petitioner, Wayne
    20
    Harris, and Marcus Player, was found inside the containment zone established by
    the police around the location where the brown Buick car had crashed while being
    pursued by the deputies. At the time of his detention, Simms falsely identified
    himself as James Taylor. When Cora and Mary Taylor were brought to the
    location of the detained suspects for a field showup, they could not identify any of
    the four. Simms was then taken to a sheriff‟s station, where his true identity was
    ascertained. At the station, Theodore Naimy, one of the deputies in the patrol car
    that had been chasing the Buick, observed Simms. Based on height, weight, age,
    and clothing, Naimy thought that Simms resembled one of the men he had seen
    running from the car, but he was uncertain of his identification. Simms, who was
    16 years old, was released without being charged with the Taylor crimes.
    During the posttrial reference hearing, an exemplar set of Simms‟s
    fingerprints, obtained by the police when Simms was arrested in 1987 (five years
    after petitioner‟s capital trial) on an unrelated matter, was compared with the latent
    prints in the Taylor home. The parties stipulated that one of the fingerprints
    matched a latent print found on a metal box in the Taylor home‟s kitchen. At the
    reference hearing, petitioner argued that Defense Counsel Skyers should have
    discovered the fingerprint match and presented evidence of it at petitioner‟s trial to
    show that petitioner was not one of the perpetrators of the Taylor crimes.
    But Defense Counsel Skyers could only have discovered and presented
    such evidence if he could have obtained an exemplar of Simms‟s fingerprints from
    law enforcement officials so that he could have asked an expert to compare it to
    the latent prints found at the Taylor home. By the time of the posttrial reference
    hearing (which began in 2006), any such exemplar no longer existed, and there
    was no way to determine whether one had existed at the time of trial. The referee
    found that petitioner had not shown that Simms‟s fingerprints had been available
    to Skyers.
    21
    Petitioner challenges this finding. According to petitioner, “Simms was
    arrested and booked into jail” and “[t]he booking process in [Los Angeles] county
    jails required taking fingerprints.” Thus, he asserts, the deputies must have taken
    Simms‟s fingerprints, and Defense Counsel Skyers could have obtained them from
    the prosecution through pretrial discovery. But petitioner presented no records
    showing that Simms was booked into the jail, and it is unlikely that he was,
    because he was a juvenile. (See Welf. & Inst. Code, former § 207, subd. (a), as
    amended by Stats. 1979, ch. 373, § 347, p. 1387 [“No . . . peace officer shall
    knowingly detain in any jail or lockup any person under the age of 18 years, unless
    a judge of the juvenile court shall determine that there are no other proper and
    adequate facilities for the care and detention of such person . . . .”].) Although it is
    possible that the deputies obtained Simms‟s fingerprints even without booking him
    into the jail, we doubt that they did so: If the fingerprints had been obtained, the
    prosecution (which was seeking to apprehend everyone responsible for the Taylor
    crimes), would most likely have compared them with those found at the Taylor
    home. Thus, we accept the referee‟s finding that petitioner failed to show that
    Defense Counsel Skyers could have obtained Simms‟s fingerprints at the time of
    petitioner‟s trial.
    d. “The referee errs in concluding that petitioner’s defense
    evidence was not credible.”
    As described in part II.B.2.a., ante, at the posttrial reference hearing
    petitioner presented evidence tending to show that he did not participate in the
    Taylor crimes. According to petitioner, the referee found that the evidence “did
    not necessarily eliminate petitioner as a perpetrator and for that reason reasonably
    competent counsel would not have presented it.” (Italics added.) Petitioner
    disputes this finding by the referee, pointing out that to prevent the jury from
    considering the Taylor crimes as evidence in aggravation at the penalty phase,
    22
    counsel only had to raise a reasonable doubt as to whether petitioner committed
    those crimes; he did not have to conclusively establish petitioner‟s innocence of
    those crimes. But the referee did not base his finding that reasonably competent
    counsel would not have presented the alibi evidence solely on the
    inconclusiveness of this evidence. Rather, the referee found that competent
    defense counsel would not have presented the alibi evidence because the alibi
    witnesses would have contradicted petitioner‟s guilt phase testimony about his
    whereabouts on the night of the Taylor crimes, would have confirmed petitioner‟s
    gang membership (which petitioner denied in his guilt phase testimony), and
    would have contradicted petitioner‟s claims at the posttrial reference hearing that
    he had brain damage and grew up in impoverished circumstances. Petitioner does
    not refute these reasons given by the referee for his finding.
    e. “The referee errs in finding that petitioner presented no
    evidence at the hearing rebutting any alleged connection
    between petitioner and the Jefferson murder.”
    The referee found that “petitioner did not present any additional mitigation
    or rebuttal evidence as to the Jefferson murder” at the posttrial reference hearing.
    Petitioner takes exception to this finding, citing the reference hearing testimony of
    Steven Strong, hired by petitioner as a private investigator. Strong had previously
    worked for the Los Angeles Police Department for 20 years; his service included
    many years as a detective focusing on criminal street gangs and several years as a
    homicide detective. In 1979 and 1980, he investigated narcotics offenses
    committed by the Raymond Avenue Crips, and he had made extensive contacts
    with members of that gang while working undercover.
    According to investigator Strong, the available evidence pertaining to the
    murder of Teheran Jefferson indicated that it was a drug-related slaying, not a
    gang-related slaying, and there was nothing unique or unusual about the murder.
    23
    He conceded, however, that the same was true of the slayings of Bobby and Eric
    Hassan, and that Jefferson‟s home was in the same block as the Hassan home. He
    acknowledged that Jefferson, like the Hassans, was killed with a .38- or .357-
    caliber weapon, but he did not regard that fact as particularly significant, noting
    that “.38‟s and .357 caliber revolvers were very commonplace” in South Central
    Los Angeles at the time of the 1980 murders.
    In response to this exception asserted by petitioner, the Attorney General
    attacks investigator Strong‟s credibility, asserting that Strong was not provided
    with and did not review certain “important materials relevant to his opinions” and
    that he used “patently defective reasoning.”
    We agree with petitioner that, contrary to the referee‟s finding, he did
    present evidence about Jefferson‟s murder. But petitioner‟s evidence did not
    consist of facts that were not presented at trial; rather, it consisted only of
    investigator Strong‟s evaluation of those facts. We see no need to determine the
    merits of the Attorney General‟s attack on the credibility of Strong‟s evaluation
    because, as explained below, it is highly unlikely that the jury considered
    Jefferson‟s murder as an aggravating circumstance at the penalty phase of
    petitioner‟s capital trial.
    At the penalty phase, the trial court correctly instructed the jurors that they
    could consider evidence that petitioner had engaged in violent criminal conduct
    other than the murders of which he was convicted only if they found beyond a
    reasonable doubt that petitioner had engaged in that conduct. No reasonable juror
    could have made such a finding with regard to the murder of Teheran Jefferson.
    True, Jefferson‟s killing resembled the murders of Bobby Hassan and
    Michael Taylor in a number of respects: Each victim was a marijuana dealer, each
    was murdered in his home, they all lived in the same neighborhood, each was shot
    with a .38- or .357-caliber weapon, and the killings all took place within a two-
    24
    month period. Although these similarities are circumstantial evidence tending to
    show that Jefferson, like the Hassans and Michael Taylor, was murdered by
    members of the Raymond Avenue Crips, they do not demonstrate beyond a
    reasonable doubt that petitioner was personally involved in the killing of
    Jefferson. In his closing argument at the penalty phase, the prosecutor did not rely
    on the Jefferson murder as a circumstance in aggravation; instead, he told the jury
    that it could consider that murder only if it found beyond a reasonable doubt that
    petitioner had committed it, and said that he would “not belabor that by asking you
    for a finding at this time.” In these circumstances, no reasonable juror would have
    regarded Jefferson‟s murder as an aggravating circumstance.
    f. “The referee erred in not recognizing that petitioner presented
    evidence mitigating his involvement in the juvenile
    offenses . . . .”
    The referee found that “[p]etitioner made no showing that any mitigating
    evidence existed at the time of the trial” as to the two felonies in which petitioner
    participated as a juvenile, evidence of which was presented to the jury at the
    penalty phase of his capital trial. Petitioner takes exception to this finding, citing
    psychologist Deborah Miora‟s testimony at the posttrial reference hearing.
    Dr. Miora explained that after the death of Gerald Trabue, Sr., who was like a
    father to petitioner until his death in a car accident when petitioner was six years
    old, petitioner grew up without a strong, nurturing father figure, in a family
    traumatized by Trabue‟s death. As a result, petitioner became involved with a
    criminal street gang, the Raymond Avenue Crips, when he was 11 years old.
    According to Dr. Miora, participation in the gang “meant having a sense of family,
    being part of a group, being taken in, being paid attention, being cared for in a way
    [when] he had felt lost at home and not recognized.” The gang, Miora said, gave
    petitioner “a feeling of belonging, a feeling that somebody was really looking after
    25
    him and cared about his whereabouts.” This evidence, petitioner asserts, mitigated
    the two felonies, which he committed with other members of that group. We
    disagree.
    Dr. Miora‟s testimony provides a possible explanation as to why petitioner
    joined the Raymond Avenue Crips. But not all members of that gang committed
    violent crimes. Petitioner‟s best friend, Gary Jones, testified that he too had been
    a member of the Raymond Avenue Crips, but that his gang-related activities
    consisted only of drinking beer, smoking marijuana, and protecting other gang
    members in fights with rival gangs. Thus, Dr. Miora‟s testimony does not explain
    why petitioner, as a juvenile, participated not only in an armed robbery of three
    persons, but also committed an assault with a knife on a man who was picnicking
    in a park with his family.
    g. “Given that gang affiliation was a noticed aggravator, the
    referee erred in refusing to fund a gang expert, thereby
    preventing petitioner from fully exploring gang related issues
    and presenting relevant mitigating evidence on this subject.”
    Petitioner asserts that the referee erred by denying his requests for funds to
    retain a gang expert, but he makes no attempt to support this bald assertion: He
    provides no record citations showing that he requested such funds; that the
    request, if any, was accompanied by an offer of proof; or that the referee denied
    the alleged request. Nor does petitioner provide any argument or case authority in
    support of his contention. We therefore do not consider this claim. (See People v.
    Stanley (1995) 
    10 Cal.4th 764
    , 793 [a court need not consider a claim that is
    accompanied by neither argument nor authority].) We note, moreover, that
    petitioner did hire a gang expert, investigator Steven Strong, who testified on his
    behalf at the posttrial reference hearing, and that psychologist Deborah Miora
    testified as to petitioner‟s reasons for joining the Raymond Avenue Crips street
    gang.
    26
    h. “The referee errs in finding that petitioner presented no
    evidence to support claims that if Skyers had properly
    investigated the taped conversation between Ross and
    petitioner he could have shown that the transcript was deficient
    or incorrect and mitigated the contents and impact of the
    recorded conversation.”
    As previously noted (see pt. I, ante), at the guilt phase of petitioner‟s capital
    trial the prosecution introduced a tape recording of a conversation between
    petitioner and codefendant Ross that occurred in a van transporting them between
    jail and the courthouse. In the conversation, petitioner and Ross talked about
    “blow[ing] up” the driver of the transport van and escaping, and petitioner laughed
    when talking about murder victim Bobby Hassan and his son, Bobby, Jr., who had
    been in the audience in court. At the penalty phase, the prosecutor cited this
    conversation as evidence that petitioner lacked remorse for the murders.
    The referee found: “Petitioner did not present any evidence [at the posttrial
    reference hearing] to support the claims that if [defense counsel] Skyers had
    properly investigated the taped conversation between Ross and petitioner he could
    have shown that the transcript was deficient or incorrect. No mitigating evidence
    [on this issue] was presented by petitioner.”
    Petitioner takes exception to this finding, claiming that he “presented
    evidence that there were numerous plausible explanations to counter arguments
    the prosecutor made regarding the taped conversation . . . .” But the testimony he
    cites to support this assertion is that of Jack Earley, a criminal defense attorney
    called by petitioner as an expert witness, who said that Defense Counsel Skyers
    “didn‟t deal with” the tape recording. Earley described some steps that a
    reasonably competent attorney could have taken to address the issue, such as
    having petitioner evaluated by a psychologist and determining whether petitioner
    was a leader or a follower. But Earley did not describe any mitigating evidence
    the defense could have presented at trial on the issue, nor did he state that the
    27
    transcript was deficient or incorrect. We therefore conclude that the record
    supports the referee‟s finding on this point.
    3. Exceptions to the referee’s findings pertaining to petitioner’s social
    history, development, and mental functioning.
    a. “The referee erred in rejecting Dr. Riley’s conclusion that
    petitioner, as of the time of his trial in 1982, suffered from
    longstanding neuropsychological dysfunction.”
    At the posttrial reference hearing, petitioner attempted to show through the
    testimony of clinical neuropsychologist Nell Riley that petitioner‟s trial counsel
    could have presented evidence that petitioner suffered from neuropsychological
    dysfunction at the time of the Hassan murders. Dr. Riley testified that in 1997 she
    gave petitioner a standard Intelligence Quotient (IQ) test, the results of which
    showed that petitioner had a verbal IQ of 92 (which placed him in the 30th
    percentile) and a performance IQ of 74 (which placed him in the fourth
    percentile). At the time of petitioner‟s capital trial, Riley testified, the scientific
    community considered a discrepancy of this magnitude between the verbal IQ and
    the performance IQ to be a marker of brain dysfunction.3 She also administered a
    series of tests called the Halstead Reitan Battery, which were used at the time of
    petitioner‟s trial to measure seven components of brain dysfunction. According to
    Dr. Riley, the tests showed petitioner was in the impaired range in all seven
    components, and only two out of every 10,000 persons are in the impaired range in
    all seven categories.
    3      Because petitioner was attempting to show that trial counsel should have
    presented evidence of petitioner‟s brain damage, Dr. Riley described the tests that
    could have been administered at the time of petitioner‟s trial and the results that
    would have been derived from those tests. Different (and presumably more
    accurate) tests are now used.
    28
    In Dr. Riley‟s view, petitioner had neuropsychological deficits in “problem
    solving, nonverbal reasoning, attention, and . . . information processing.” These
    deficits, she said, caused him to be “unable to draw inferences in ambiguous
    circumstances and . . . especially vulnerable to missing or misleading cues
    concerning the intentions of other persons”; they also impaired “his ability to
    comprehend the whole situation and make decisions.” Dr. Riley cited as possible
    causes of petitioner‟s impairments the facts that petitioner was in an automobile
    accident when he was a child and his mother‟s physical abuse at the hands of
    petitioner‟s father while she was pregnant with petitioner.
    To rebut Dr. Riley‟s testimony, the prosecution called forensic psychiatrist
    Saul Faerstein and neuropsychologist Charles Hinkin. Drs. Faerstein and Hinkin
    both concluded, based on the reports of the six mental health experts who had
    examined petitioner before trial (four at CYA, and two on behalf of the defense),
    that petitioner does not suffer from brain damage, and that there had been no
    reason for Defense Counsel Skyers to have a neuropsychologist examine
    petitioner.
    Dr. Hinkin disagreed with Dr. Riley‟s testimony that her tests showed that
    petitioner suffered from brain damage. He criticized Riley for allowing habeas
    corpus counsel to be present during some of the tests, explaining that a third
    party‟s presence may alter a subject‟s performance on the tests. And Dr. Hinkin
    disagreed with Dr. Riley‟s method of scoring the tests given. He explained that
    because Blacks ordinarily perform more poorly than Whites on those tests, it is
    preferable to use ethnically corrected norms when scoring the tests, which
    Dr. Riley did not do. Once the test results were corrected for ethnicity, he said,
    many of Dr. Riley‟s tests showed that petitioner fell within the normal range,
    while others showed that he was in the “low average” or “mildly impaired” range
    and none showed that he was in the “impaired” range.
    29
    The referee found that Drs. Riley, Hinkin, and Faerstein were “all
    impressive, well qualified witnesses,” but he was persuaded by the reasoning of
    prosecution experts Hinkin and Faerstein. The referee expressed doubt that the
    three events cited by petitioner as possible causes of his alleged mental
    impairments (fetal abuse, head injury in a traffic accident, and physical abuse by
    his siblings) could have resulted in such impairments, if they in fact occurred. The
    referee noted that none of the six mental health professionals who had examined
    petitioner before trial had detected any mental defects, disorders, or significant
    impairments, and none had “recommended additional psychological or
    neuropsychological testing of petitioner.” The referee therefore concluded that
    petitioner had presented “no credible evidence that [he] suffered from any brain
    damage or dysfunction at the time of petitioner‟s 1982 trial,” and that Dr. Riley‟s
    opinion to the contrary was “not supportable.”
    Petitioner takes exception to the referee‟s finding that he had no
    neuropsychological impairments at the time of his capital trial. He points out that
    none of the four mental health professionals who had evaluated him at CYA
    testified at the posttrial reference hearing, nor did Drs. Imperi and Pollack, who
    had evaluated petitioner for the defense before trial. Instead, the prosecution
    relied on the testimony of Drs. Hinkin and Faerstein, neither of whom had
    personally examined petitioner. (See People v. Bassett (1968) 
    69 Cal.2d 122
    , 142-
    146 [rejecting testimony by prosecution psychiatrists who had not examined the
    defendant and who provided essentially no reasons for their conclusion that he did
    not suffer from diminished capacity].) Petitioner asserts that because none of the
    mental health professionals who examined him at CYA and before trial was a
    neuropsychologist, defense neuropsychologist Riley was better able than they
    were to determine whether he was neuropsychologically impaired.
    30
    In response, the Attorney General notes that the parties stipulated that, at
    the time of the posttrial reference hearing, the four mental health professionals
    who had evaluated petitioner at CYA had no recollection of those evaluations.
    The Attorney General argues that even though Drs. Hinkin and Faerstein did not
    personally evaluate petitioner, they could reasonably rely on the information in the
    reports of those four mental health professionals, as well as Dr. Riley‟s report, in
    concluding that petitioner was not neuropsychologically impaired at the time of
    the murders, and that therefore the testimony of Drs. Hinkin and Faerstein
    supports the referee‟s finding that petitioner was not impaired. The Attorney
    General also argues that the reliability of defense expert Riley‟s evaluation was
    undermined by the presence of habeas corpus counsel during her evaluation of
    petitioner (see In re Spencer (1965) 
    63 Cal.2d 400
    , 411 [“Surely the presence and
    participation of counsel would hinder the establishment of the rapport that is so
    necessary in a psychiatric examination”]), and by Dr. Riley‟s failure to use
    ethnically corrected norms in evaluating the results of the neuropsychological tests
    she administered to petitioner (although these were not in use at the time of
    petitioner‟s trial).
    We need not resolve this dispute. We did not ask the referee to decide
    whether petitioner was neuropsychologically impaired at the time of his capital
    trial, and the answer to that question does not assist us in deciding whether
    Defense Counsel Skyers competently assisted him at the penalty phase of trial.
    Rather, we asked the referee to decide what mitigating evidence Skyers could have
    presented at trial, and we asked how credible that evidence would have been.
    With respect to Dr. Riley‟s testimony that petitioner had neuropsychological
    impairments, the referee did not answer the first part of our question, but we
    assume for the sake of argument that Defense Counsel Skyers could have
    presented that evidence at trial. As to the second part of the question, the referee
    31
    found that Dr. Riley‟s testimony was “not supportable” and implicitly found it not
    to be credible.
    Regardless of whether, as petitioner now argues, Dr. Riley‟s reference
    hearing testimony was credible, we agree with the referee that Defense Counsel
    Skyers had not been incompetent at trial for not discovering it. The referee found
    that in preparing for the trial‟s penalty phase, Skyers reviewed the reports of two
    psychologists and two psychiatrists who had evaluated petitioner at CYA, and a
    report prepared by two psychiatrists who had evaluated him at the request of
    Homer Mason, the attorney initially appointed to represent petitioner in his capital
    trial. None of the reports found any evidence that petitioner suffered from any
    psychiatric impairment. Indeed, the report prepared by Dr. Pollack (described by
    prosecution witness Dr. Faerstein as “one of the premier forensic psychiatrists in
    the United States”) along with Dr. Imperi, stated that “there does not appear to be
    any evidence of mental illness, defect or disorder . . . .” We agree with the referee
    that, after reading these reports, a reasonably competent attorney could make a
    tactical decision not to retain a neuropsychologist to explore the possibility that
    petitioner had suffered from any neuropsychological impairments. Thus,
    regardless of the credibility of Dr. Riley‟s reference hearing testimony, Defense
    Counsel Skyers‟s failure to locate her (or some other neuropsychologist with
    similar views) did not violate petitioner‟s right to representation by competent
    counsel. (See In re Fields (1990) 
    51 Cal.3d 1063
    , 1075 [“When three experts
    concur in a diagnosis, competent counsel might reasonably believe it pointless to
    search further in the hope of finding an expert who would offer a different
    diagnosis . . . .”]; People v. Williams (1988) 
    44 Cal.3d 883
    , 945 [“Competent
    representation does not demand that counsel seek repetitive examinations of the
    defendant until an expert is found who will offer a supportive opinion”]; see also
    People v. Payton (1992) 
    3 Cal.4th 1050
    , 1078.)
    32
    b. “Based on his misunderstanding of what constitutes mitigating
    evidence and the relationship of proffered evidence to
    petitioner’s functioning and development, . . . the referee . . .
    erroneously excluded evidence in mitigation, deemed it
    irrelevant, and/or gave it little weight.”
    Petitioner challenges a number of the referee‟s evidentiary rulings and
    findings, claiming they reflect an unduly narrow view of the scope of mitigating
    evidence.
    (1) At the posttrial reference hearing, petitioner asked defense psychologist
    Deborah Miora about her reliance on a report prepared at CYA that said
    petitioner‟s younger half brother Gerald Trabue, Jr. (who, like petitioner, had been
    incarcerated at CYA) told an intake officer that Henry Robinson, who for one year
    was the stepfather of petitioner and Trabue, had hit Trabue with a stick, a belt, and
    shoes. The prosecution objected that petitioner was attempting to introduce, for its
    truth, circumstantial hearsay evidence that Robinson had physically abused
    petitioner. After a long discussion, the referee sustained the objection. According
    to petitioner, the referee ruled that Dr. Miora could not “base any opinions on” the
    report in question. Petitioner overstates the scope of the ruling. The referee
    simply barred Dr. Miora from describing the details of the CYA report on which
    she based her testimony, a ruling that was within the referee‟s discretion. (See
    People v. Coleman (1985) 
    38 Cal.3d 69
    , 92 [“ „While an expert may state on direct
    examination the matters on which he relied in forming his opinion, he may not
    testify as to the details of such matters if they are otherwise inadmissible.‟ ”].)
    (2) According to petitioner, the referee “limited Dr. Miora‟s discussion of
    themes such as poverty, abuse, and other negative impacts on petitioner to only
    those he recalled and discussed with Dr. Miora during her interviews with
    petitioner.” But the transcript pages he cites contain no such ruling.
    33
    (3) Petitioner challenges the referee‟s finding that the life history of
    petitioner‟s half brother, Gerald Trabue, Jr. was “immaterial to petitioner.”
    Petitioner argues that because Gerald, Jr. was born only 11 months after petitioner
    and the two of them grew up together, evidence of Gerald‟s childhood sheds light
    on petitioner‟s own history. We agree with petitioner that Gerald‟s life history had
    some relevance to petitioner‟s childhood development, and that this one-sentence
    finding by the referee was erroneous.
    (4) Petitioner disputes the referee‟s finding that the documents in
    petitioner‟s exhibit No. 141 were irrelevant. This exhibit consisted of news stories
    about conditions in South Central Los Angeles after the 1965 riots that occurred in
    Watts (a neighborhood in Los Angeles), a report by the American Civil Liberties
    Union on police misconduct during the riots, studies by university professors on
    demographic changes in Watts and attitudes of members of the Watts community
    toward the police, and a timeline of “environmental justice in Los Angeles”
    prepared by the Environmental Defense Fund. According to petitioner, the
    documents “tended to corroborate the accounts of lay witnesses about conditions
    in the community and in youth facilities,” and had “a tendency in reason to
    demonstrate the credibility” of petitioner‟s witnesses. But the conditions in Watts
    were not at issue at the posttrial reference hearing, and petitioner does not explain
    how or why the reports supported the credibility of any of his witnesses. We
    therefore agree with the referee‟s finding that the documents were irrelevant.
    (5) At the posttrial reference hearing, petitioner proffered reports asserting
    police brutality against Blacks during the Watts riots while petitioner (then three
    years old) was living there. The referee described the authors of these reports as
    “very slanted or biased.” Petitioner argues that even if the authors were biased,
    the reports were relevant because they were circumstantial evidence tending to
    show that members of petitioner‟s family held views about the police similar to
    34
    those expressed in the report. Assuming for the sake of argument that this is true,
    those views do not mitigate the Hassan murders petitioner committed.
    (6) Petitioner challenges a ruling by the referee pertaining to the testimony
    of his uncle, E.I. Gaithright, and his mother, Azell. When petitioner tried to
    question Gaithright about growing up on a Mississippi farm, picking cotton,
    plowing fields and milking cows, the referee sustained the prosecutor‟s objection,
    ruling that the testimony was irrelevant. Later, the referee excluded testimony by
    Azell about physical abuse she suffered as a child in Mississippi.
    Petitioner asserts that the poverty, racism, limited schooling, and violence
    experienced by petitioner‟s mother and her siblings while growing up in
    Mississippi “was relevant to an understanding of the personal resources [they]
    brought to the difficult task of raising a large family in South Central Los Angeles,
    and explained why [petitioner‟s mother] may have been hampered in her ability to
    provide for and guide her children, why she may . . . [not have] accessed public
    resources available to assist her and her family . . . and why she might have been
    more hesitant to call upon police for protection from domestic and neighborhood
    violence.” Even if that is so, the conditions in which petitioner‟s mother and her
    siblings were raised do not mitigate petitioner‟s criminal conduct. “[T]he
    background of the defendant’s family is of no consequence in and of itself . . .
    because . . . the determination of punishment in a capital case turns on the
    defendant‟s personal moral culpability. It is the „defendant’s character or record‟
    that „the sentencer . . . [may] not be precluded from considering‟ — not his
    family’s.” (People v. Rowland (1992) 
    4 Cal.4th 238
    , 279; see also In re Scott
    (2003) 
    29 Cal.4th 783
    , 821.) Evidence that petitioner‟s mother was a bad parent
    (which could evoke sympathy for petitioner) would have been admissible; but
    evidence of childhood experiences that might have made her a bad parent (which
    could only evoke sympathy for petitioner‟s mother) was not.
    35
    (7) Petitioner challenges the referee‟s exclusion of proffered testimony that
    during the Watts riots his sister, who was then six or seven years old, heard
    gunshots, helicopters, and bullhorns advising residents of a dusk-to-dawn curfew,
    and saw National Guardsmen with rifles in the street. Petitioner asserts that the
    referee‟s exclusion of this testimony “reflects a stunningly narrow view of the
    scope of mitigation.” We disagree. Any conceivable probative value of this
    testimony was so slight that the referee could properly exclude it on the ground
    that it would “necessitate undue consumption of time.” (Evid. Code, § 352.)
    Petitioner also claims that the referee improperly precluded defense psychologist
    Miora from testifying about how the riots affected petitioner‟s functioning and
    development. We discern no such ruling on the page of the hearing transcript he
    cites.
    (8) Petitioner asserts that the referee “improperly rejected a large body of
    mitigating life history information on the ground that the family had not offered it
    to trial counsel.” (Italics added.) It is unclear what petitioner means by
    “rejected.” He may be arguing that the referee excluded relevant mitigating
    information on the ground that members of the family did not tell trial counsel
    about it; or perhaps he is arguing that the referee found that relevant mitigating
    information admitted into evidence at the posttrial reference hearing was not
    credible because family members did not tell trial counsel about it. In either event,
    petitioner makes no citation to either the record or the referee‟s report to support
    his assertion. We therefore reject it.
    (9) Petitioner questions the referee‟s finding that if members of his family
    had testified on his behalf at the penalty phase of his capital trial, the jury might
    not have believed them because his mother Azell, his sister Rita, and his brother
    Reggie had testified on petitioner‟s behalf at the guilt phase, and the jury
    implicitly rejected their testimony when it convicted him of murdering Bobby and
    36
    Eric Hassan. (See p. 4, ante.) Petitioner states that Defense Counsel Skyers could
    have called other family members to testify on his behalf, and that in any event the
    jury might have believed testimony of Azell, Rita, and Reggie about petitioner‟s
    childhood experiences even after rejecting their guilt phase testimony. But the
    referee found only that reasonably competent counsel might have decided for
    tactical reasons not to call Azell, Rita, and Reggie to testify at the penalty phase
    after the jury had already rejected their guilt phase testimony. Petitioner makes no
    showing of error in the referee‟s finding.
    (10) In his report, the referee stated, with regard to a declaration signed by
    psychologist Miora: “The 154 page „Petitioner‟s Life History‟ Core of
    „Dr. Miora‟s‟ 213 page . . . declaration . . ., created by petitioner’s counsel and not
    the witness, reflects a biased and highly selective „spin‟ of the reference hearing
    evidence and exhibits.” (Fn. deleted.) Petitioner asserts that this statement
    “erroneously and falsely accused habeas counsel of professional misconduct for
    aiding in the preparation of a declaration intended as a proffer of evidence.” We
    perceive no accusation of misconduct. The referee simply noted the fact, which
    petitioner does not dispute, that defense expert Miora‟s declaration, filed by
    petitioner as an offer of proof describing her anticipated testimony at the posttrial
    reference hearing, was prepared primarily by habeas corpus counsel. The referee
    did not suggest that habeas corpus counsel committed misconduct by personally
    drafting the offer of proof instead of asking Dr. Miora to do so. Although the
    referee found the declaration to be a “biased and highly selective „spin‟ of the
    reference hearing evidence and exhibits,” that finding is not an accusation of
    misconduct; rather, it is an explanation as to why the referee found the declaration
    unpersuasive.
    37
    C. What investigative steps, if any, would have led to the mitigating
    evidence described in the previous question? In 1982, when
    petitioner’s case was tried, would a reasonably competent attorney
    have tried to obtain such evidence and to present it at the penalty
    phase?
    1. Referee’s findings
    The referee found that the evidence just described could have been obtained
    by “retaining . . . an evidence and penalty phase investigator.”
    With regard to whether a reasonably competent attorney would have tried
    to obtain the evidence described above, the referee found that a reasonably
    competent attorney would have: (1) retained an investigator and conducted
    interviews to try to establish alibis for the murder of Teheran Jefferson and the
    Taylor crimes; (2) interviewed CYA staff about petitioner‟s adjustment while
    incarcerated there; (3) reviewed petitioner‟s school records; (4) reviewed the CYA
    medical reports; (5) interviewed all members of petitioner‟s immediate family to
    prepare a social history; (6) investigated petitioner‟s involvement in the Raymond
    Avenue Crips; (7) determined whether petitioner was drug dependent and whether
    that dependence had any relevance in mitigation; (8) investigated petitioner‟s
    employment history; (9) reviewed petitioner‟s criminal history; (10) reviewed
    petitioner‟s history as a juvenile offender; (11) consulted forensic, fingerprint,
    firearms, and gang experts, and consulted with doctors as to petitioner‟s mental
    status; (12) reviewed the transcripts of the preliminary hearing and trial of Evan
    Mallet, who was convicted as one of the perpetrators of the Taylor crimes; and
    (13) investigated to determine whether there was any other mitigating factor or
    theme.
    The referee found that before petitioner‟s capital trial, Defense Counsel
    Skyers reviewed petitioner‟s school records and CYA medical records, as well as
    38
    petitioner‟s criminal history and history as a juvenile offender, and that Skyers did
    an investigation to determine whether there was some mitigating factor or theme
    he could present to the jury. He also interviewed some, but not all, of the
    members of petitioner‟s immediate family, and he reviewed an evaluation of
    petitioner‟s mental status that was obtained by Homer Mason, who had initially
    represented petitioner. Skyers did not perform the other investigative steps
    described above: He did not investigate the Taylor and Jefferson murders; he did
    not interview pertinent CYA employees; he did not interview some members of
    petitioner‟s immediate family; he did not investigate petitioner‟s gang
    involvement; he did not determine whether petitioner was drug dependent; he did
    not interview petitioner‟s employers; he did not consult forensic, fingerprint,
    firearms, and gang experts; and he did not review the transcripts of Mallet‟s
    preliminary hearing and trial.
    With respect to what evidence a reasonably competent attorney would have
    presented at trial, the referee found:
    (1) Reasonable counsel would not have presented an alibi for the murder of
    Teheran Jefferson, as such evidence was not presented at the posttrial reference
    hearing.
    (2) Reasonable counsel would not have presented an alibi defense for the
    crimes committed in the Taylor home, because the alibi witnesses at the posttrial
    reference hearing were not credible, and because alibi witness Marcus Player
    would not have cooperated with the defense at the time of trial.
    (3) Reasonable counsel would not have presented evidence of petitioner‟s
    good adjustment at CYA, because the prosecution would have been able to rebut
    that evidence with evidence that while petitioner was at CYA he committed “acts
    of misconduct,” and soon after his release from CYA he murdered Bobby and Eric
    Hassan.
    39
    (4) Reasonable counsel would not have presented evidence contained in
    the CYA medical reports, because those reports revealed no evidence of mental
    illness.
    (5) Reasonable counsel would have presented, if the evidence was
    disclosed to him, evidence of the love and affection that petitioner‟s family
    members had for petitioner, of the difficulties petitioner‟s mother encountered in
    raising a large family as a single mother with a limited income, of the absence of a
    father figure in petitioner‟s life when he was a child, of the impact of the death of
    Gerald Trabue, Sr. (who acted like a father toward petitioner until he was killed in
    an automobile accident when petitioner was six years old), and of the difficulties
    petitioner experienced in school. Although petitioner also presented evidence at
    the posttrial reference hearing that his family suffered from extreme poverty,
    malnutrition, and inadequate clothing, the referee made no findings with regard to
    whether reasonable counsel would have presented such evidence, possibly because
    the referee found that this evidence was not credible and that petitioner‟s family
    was unwilling to disclose those matters at the time of petitioner‟s capital trial.
    (6) Reasonable counsel would not have presented evidence about
    petitioner‟s gang membership, as the reference hearing testimony confirmed that
    petitioner had been an active, hardcore gang member from the age of 12.
    (7) Reasonable counsel would not have presented evidence of petitioner‟s
    substance abuse, because such evidence was lacking, although he did smoke
    marijuana.
    (8) Reasonable counsel would not have presented evidence of petitioner‟s
    probation and parole history, which was unfavorable to petitioner.
    (9) Reasonable counsel would not have presented evidence of petitioner‟s
    history as a juvenile offender, because it included acts of violence and a burglary,
    and thus was unfavorable to petitioner.
    40
    The Attorney General does not dispute the referee‟s findings described
    above. Petitioner has two exceptions, which we address below.
    2. Petitioner’s exceptions to referee’s findings
    a. “The referee erroneously attributes Skyers’s failure to uncover
    mitigating evidence to a family member conspiracy to keep
    information from him.”
    The referee found that “nondisclosure of family history by petitioner or
    members of his immediate family was purposeful and that no attorney or
    investigator could have developed the family mitigation . . . presented [at the
    posttrial reference hearing] in view of the failure to disclose.” The referee later
    observed: “[E]ven if petitioner‟s present claims of mitigating evidence available
    to present at petitioner‟s trial in 1982 are credible, the failure of petitioner‟s trial
    counsel to uncover and present such mitigating evidence is not the product of any
    deficient performance by trial counsel; rather, it is the product of the Champion
    family not disclosing family business to petitioner‟s trial counsel, Ronald Skyers.”
    Petitioner asserts that the referee found a “conspiracy” by members of his
    family to withhold information from Defense Counsel Skyers. He argues that it
    was his counsel‟s obligation to seek out relevant information about petitioner‟s
    upbringing, and that the blame for failing to discover it should be attributed not to
    petitioner‟s family but to his counsel.
    We agree with petitioner that to conduct a reasonably competent
    investigation, defense counsel in a capital case must often explain to family
    members that “negative” information about the defendant‟s childhood is often a
    crucial part of the defense‟s penalty presentation in a capital case, and therefore
    the family should not withhold such information. Here, Defense Counsel Skyers‟s
    reference hearing testimony contains no indication that he explained this to
    petitioner‟s family. (See In re Lucas (2004) 
    33 Cal.4th 682
    , 729-730 [the
    41
    petitioner‟s failure to reveal that he had been abused as a child did not excuse trial
    counsel‟s “perfunctory investigation” because the petitioner would not have
    understood the significance of such information and counsel “did not press [the]
    petitioner to reveal information concerning such matters”].) Had Skyers done so,
    it is unlikely that petitioner‟s family would have withheld such information, in
    view of the referee‟s finding that they loved petitioner and the evidence that they
    pooled their resources, using money they could ill afford to spend, to hire Skyers
    to represent petitioner.
    That said, petitioner‟s assertion that the referee found a family “conspiracy”
    to withhold evidence overstates the referee‟s findings. The referee found no
    conspiracy; rather, he correctly observed that at the time of petitioner‟s capital trial
    the members of his family chose not to mention negative aspects of petitioner‟s
    upbringing to Defense Counsel Skyers. This circumstance necessarily made it
    more difficult for Defense Counsel Skyers to discover such information for use at
    the trial‟s penalty phase.
    b. “The referee erred in failing to fully credit the Strickland
    expert’s opinions.”
    At the posttrial reference hearing, petitioner called Jack Earley, an
    experienced criminal defense attorney, who testified that in 1982, when petitioner
    was tried for the Hassan murders, a reasonably competent attorney would have
    conducted a far more thorough investigation than that done by Defense Counsel
    Skyers. The Attorney General‟s cross-examination, which took up more than 800
    pages of transcript, focused on a different question: whether a reasonably
    competent attorney would have presented, at trial, the evidence that was gathered
    by petitioner‟s habeas corpus counsel and introduced at the posttrial reference
    hearing.
    42
    The referee generally agreed with Attorney Earley that Defense Counsel
    Skyers‟s penalty phase investigation fell below the standard of a reasonably
    competent attorney in 1982. But the referee concluded that a reasonably
    competent attorney would not have presented, at the penalty phase of petitioner‟s
    trial, the bulk of the evidence petitioner produced at the posttrial reference hearing.
    Petitioner takes exception to the referee‟s finding, challenging both its form and its
    substance.
    As to its form, the referee‟s report has a long and detailed critique of
    Earley‟s testimony. As petitioner points out, this critique was copied almost
    verbatim from proposed findings of fact prepared by the Attorney General.
    Petitioner cites some decisions in civil cases that have criticized trial courts for
    using findings of fact prepared by a party (see, e.g., Anderson v. Bessemer City
    (1985) 
    470 U.S. 564
    , 572 [“We . . . have criticized courts for their verbatim
    adoption of findings of fact prepared by prevailing parties . . . .”]) and petitioner
    argues that this criticism should also apply to referees in habeas corpus reference
    hearings. He also relies on a decision of the Indiana Supreme Court in a criminal
    case, which states: “[W]e do not prohibit the practice of adopting a party‟s
    proposed findings. But when this occurs, there is an inevitable erosion of the
    confidence of an appellate court that the findings reflect the considered judgment
    of the trial court.” (Prowell v. State (Ind. 2001) 
    741 N.E.2d 704
    , 709.)
    Petitioner‟s argument here is, in essence, the reverse of the argument he
    made in a previously discussed exception. There, he defended a declaration
    signed by one of his expert witnesses (psychologist Miora) but authored in part by
    his habeas corpus counsel. (See pt. II.B.3.b., ante.) Here, he criticizes the referee
    for signing a report that was authored in part by the Attorney General.
    In our view, a referee‟s report, like an expert witness‟s declaration, may
    properly contain materials drafted by counsel. But because lawyers are advocates
    43
    and not arbiters, their work may lack the impartiality of a report done personally
    by the referee. Here, the referee‟s report describes psychologist Miora‟s
    declaration (drafted by petitioner‟s habeas corpus counsel) as “a biased and highly
    selective „spin‟ of the reference hearing evidence and exhibits.” We do not quarrel
    with that description; an objective reader might come to a similar conclusion with
    respect to that portion of the referee‟s report that discussed Attorney Earley‟s
    reference hearing testimony and was drafted by the Attorney General.
    In any event, the referee‟s critique of Attorney Earley‟s testimony about
    which petitioner complains pertains almost entirely to the testimony Earley gave
    on cross-examination by the Attorney General, as to whether a reasonably
    competent attorney would have presented, at the penalty phase of petitioner‟s
    capital trial, the evidence that habeas corpus counsel presented at the posttrial
    reference hearing. This portion of Earley‟s testimony was of relatively little value,
    for two reasons. First, Earley was not present during and did not read the
    testimony of the witnesses at the reference hearing, nor did he read all of the
    transcripts of the trials of petitioner and Evan Mallet, thereby limiting his ability to
    determine what evidence a reasonably competent attorney would have presented at
    trial. Second, although Earley gave helpful testimony on the type of investigation
    that was customarily conducted more than 30 years ago, when petitioner‟s trial
    occurred, the question of which evidence a reasonably competent trial counsel
    should have presented is primarily a question of law for this court to decide.
    With regard to the substance of the referee‟s finding in question, petitioner
    defends Attorney Earley‟s reference hearing testimony on direct examination
    describing the type of investigation that, in Earley‟s view, a reasonably competent
    trial attorney would have undertaken. It is unclear why petitioner sees a need to
    defend this portion of Earley‟s testimony, because the referee generally agreed
    with it.
    44
    The referee found that some of Attorney Earley‟s opinions at the posttrial
    reference hearing were “flawed because he employed a standard of whether he
    would or would not have taken certain action, rather than the appropriate and
    applicable standard of whether reasonably competent trial counsel would or would
    not have taken the action.” Petitioner takes exception, asserting that Earley‟s
    testimony reflected the correct legal standard. Because the referee did not specify
    the portions of Earley‟s extensive reference hearing testimony that the referee
    viewed as relying on an inappropriate standard, we cannot assess the accuracy of
    the referee‟s finding, and we see no need to do so because the referee‟s vague
    finding on this point does not affect our resolution of petitioner‟s claim of
    incompetent representation at trial by Defense Counsel Skyers.
    D. What circumstances, if any, weighed against the investigation or
    presentation of the mitigating evidence not presented by counsel at
    trial? 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 this evidence?
    1. Referee’s findings
    The referee found that these circumstances weighed against investigation
    by trial counsel of the additional evidence proposed by petitioner: (1) Petitioner‟s
    family members did not disclose adverse family history to Defense Counsel
    Skyers; (2) alibi witness Marcus Player was not available to Defense Counsel
    Skyers; (3) it is unknown whether Evan Mallet, who was convicted at a separate
    trial of the Taylor crimes, was available or willing to testify on petitioner‟s behalf;
    (4) it is unknown whether Lewis Champion III, one of petitioner‟s brothers, was
    available or willing to testify on petitioner‟s behalf; (5) the psychiatric evidence
    available to Defense Counsel Skyers suggested that there was no need for him to
    hire an expert to conduct a neuropsychological examination; (6) it is “highly
    unlikely” that alibi witnesses who were members of the Raymond Avenue Crips
    45
    (Marcus Player, Wayne Harris, and Earl Bogans) were available or willing to
    testify; and (7) there is “insufficient evidence from which to conclude that . . .
    Robert Simms‟ fingerprints were available.”
    The referee found that these circumstances weighed against the
    presentation at trial of the additional evidence proposed by petitioner at the
    posttrial reference hearing: (1) “[K]ey family members” lacked credibility
    because the jury had rejected their guilt phase testimony, and the prosecution had
    access to records from CYA and petitioner‟s school that contained statements
    from petitioner and his mother contradicting certain testimony offered by members
    of petitioner‟s family at the reference hearing. (2) The defense lacked
    documentary support for claims that petitioner had brain damage resulting from
    fetal abuse, traffic accident head trauma, or head injuries resulting from beatings
    by other family members. (3) As to testimony by members of petitioner‟s family
    that as a child he suffered from extreme poverty and malnutrition and lacked
    clothing (testimony that the referee found not to be credible), the defense at trial
    would have needed to “modify” that testimony to testimony that was “consistent
    with the . . . evidence” — that petitioner‟s mother was a single parent who
    struggled, financially and emotionally, to provide support and care to a large
    family. (4) Psychiatric and psychological reports from CYA contradicted
    petitioner‟s evidence that he suffered from mental defects or disorders. (5) No
    family members, relatives, friends, or neighbors, of petitioner were willing to say
    that he suffered from any type of mental impairment. (6) The prosecution at trial
    could have presented additional evidence of petitioner‟s gang membership and
    violent history. (7) The prosecution could have countered some of the mitigating
    evidence with petitioner‟s prior statements to CYA authorities and law
    enforcement.
    46
    With regard to rebuttal evidence that the prosecution would likely have
    presented if the defense, at petitioner‟s capital trial, had introduced the mitigating
    evidence presented at the posttrial reference hearing, the referee made these
    findings:
    (1) If the defense at trial had presented alibi evidence pertaining to the
    Taylor crimes, the prosecution could have elicited testimony from two of
    petitioner‟s alibi witnesses — Wayne Harris and Earl Bogans — that they,
    petitioner, and the third alibi witness (Marcus Player) were all members of the
    Raymond Avenue Crips, and that testimony would have contradicted petitioner‟s
    guilt phase testimony at trial that he and the others were not gang members. The
    prosecution could have shown that at the time of petitioner‟s trial, alibi witness
    Marcus Player was awaiting trial on a murder charge. The prosecution could have
    elicited testimony from alibi witness Harris that Harris went to petitioner‟s home,
    where he saw codefendant Ross, after being questioned by sheriff‟s deputies on
    the night of the Taylor crimes. If psychologist Miora had testified at trial as a
    defense expert, the prosecution on cross-examination could have elicited from her
    the information that Ross was one of petitioner‟s best friends. (Evidence linking
    petitioner to Ross would have supported the prosecution‟s argument that petitioner
    was one of the perpetrators of the Taylor crimes, because there was overwhelming
    evidence that Ross was one of the perpetrators.)
    (2) If the defense at trial had presented evidence that petitioner grew up in
    poverty, that he suffered malnutrition, that he was physically abused by his
    siblings, that he was a follower, and that he had neuropsychological deficits, the
    prosecution could have rebutted this evidence with testimony from petitioner‟s
    alibi witnesses (Harris, Bogans, and Player), all of whom testified at the posttrial
    reference hearing that petitioner was not a follower, that he did not live in poverty,
    that he did not appear malnourished, that he never complained of physical abuse
    47
    by his siblings, and that he showed no signs of mental problems. Similarly, if the
    defense had called Gary Jones, who testified about his childhood friendship with
    petitioner, the prosecution could have elicited testimony from Jones that petitioner
    did not suffer from poverty, malnutrition, and physical abuse as a child.
    (3) The prosecution at trial could have used, to rebut testimony that
    petitioner suffered brain damage in utero, the statements of petitioner‟s mother to
    school authorities that she had a normal childbirth. The prosecution could have
    used the statements of petitioner‟s mother to CYA authorities that all was well at
    petitioner‟s home, as well as petitioner‟s statements to CYA authorities that he had
    a “regular family,” to rebut testimony that petitioner was abused by his siblings.
    The prosecution could have used petitioner‟s statements to CYA authorities that
    he was not a follower or easily influenced by others to rebut evidence that he did
    not play a leading role in the murders.
    (4) A “mitigation expert . . . [testifying about] positive CYA adjustment,
    child development/functioning, increasing community dangers, lack of gang
    involvement and lack of association with Raymond Avenue [Crips] gang
    members, might be questioned about petitioner‟s violent history, gang
    membership or petitioner‟s prior statements.”
    (5) Petitioner “had an extensive, violent criminal arrest record” which
    “might [have] become admissible to impeach a witness or impeach the basis of
    petitioner[‟s] mitigation expert‟s opinion.” The prosecution at trial could also
    have presented additional details of the two robberies petitioner committed as a
    juvenile, facts that were not all presented to the jury.
    (6) The prosecution could have responded to defense efforts to minimize
    the extent of petitioner‟s participation in the Raymond Avenue Crips with
    “evidence showing the degree and extent of petitioner‟s involvement in gangs.”
    48
    (7) If the defense had presented evidence that petitioner lived in an
    increasingly dangerous neighborhood as a teenager, the prosecution could have
    responded with evidence that petitioner was a gang member from the age of 12
    and that his gang, the Raymond Avenue Crips, committed most of the violent
    crimes that made the neighborhood dangerous.
    (8) The prosecution at trial could have used petitioner‟s arrest records to
    show petitioner‟s “extended association” with Evan Mallet, Michael Player, and
    Craig Ross, all of whom participated in the Taylor crimes.
    (9) If the defense at trial had presented evidence that petitioner was
    amenable to rehabilitation in a structured setting, the prosecution could have
    introduced petitioner‟s statements to a CYA psychologist that he was not easily
    influenced by others and that he committed crimes for “fast money” and because
    he “could get away with things,” and the prosecution could have pointed out that
    petitioner participated in the murders of Bobby and Eric Hassan less than two
    months after his release from CYA. The prosecution could also have presented
    evidence that, while at CYA, petitioner led a race-based riot and assaulted another
    inmate.
    2. Attorney General’s exceptions to referee’s findings
    a. Petitioner’s difficulties in school
    The referee found: “The only areas . . . that should have been presented if
    disclosed are: . . . family members‟ love and affection [for] petitioner; his traits of
    being loving toward them and his protective nature; Mrs. Champion‟s difficulties
    in being a single parent and raising a large family with very limited income; the
    absence of a father figure . . .; the impact that Trabue Sr.‟s death had on the
    family; and petitioner‟s school difficulties.” According to the referee, the
    “nondisclosure of relevant family history” by petitioner‟s family “precluded
    49
    attorney Skyers from considering these mitigation themes.” The referee also
    found, however, that Skyers should have independently reviewed petitioner‟s
    school records and interviewed his teachers.
    The Attorney General takes exception to these findings to the extent they
    “might be interpreted as a finding that Skyers was deficient for not presenting
    [evidence that petitioner had] „school difficulties‟ at the penalty phase.” The
    Attorney General points out that the referee found that “when petitioner put his
    mind to his education, he could be successful,” but “when he preferred to
    participate with his gang beginning at age 12 or 13 . . . his school work suffered.”
    She also notes that the referee found that the prosecution could have “neutralized”
    evidence of petitioner‟s difficulties in school with evidence of petitioner‟s gang
    involvement and school records indicating that petitioner “could do well when he
    applied himself.” Thus, the Attorney General argues, had Defense Counsel Skyers
    presented evidence of petitioner‟s “school difficulties” at the penalty phase of trial,
    the prosecution would have been able to counter that evidence with evidence that
    those difficulties resulted from choices petitioner made, not from limitations on his
    ability, and Defense Counsel Skyers made a reasonable tactical decision not to
    present evidence of petitioner‟s “school difficulties.”
    The Attorney General‟s argument is unpersuasive. As the referee
    explained, Defense Counsel Skyers could have presented psychiatric evidence that
    petitioner suffered from “a low IQ, low intellectual functioning, reading and
    learning difficulties, attention deficits . . . , deficiency in ability to conceptualize,
    [and] low self esteem.” A jury could reasonably have concluded that petitioner‟s
    poor performance in school was attributable at least in part to those deficits.
    Petitioner‟s membership in the Raymond Avenue Crips (of which the jury was
    already aware) and comments in petitioner‟s school records that he could do well
    50
    when he applied himself are not persuasive reasons for defense counsel‟s failure to
    present such evidence at the penalty phase of the trial.
    The Attorney General argues that if petitioner had presented evidence at the
    penalty phase of trial that his school difficulties resulted from extreme poverty or
    from brain damage caused by fetal abuse, sibling abuse, or head injury, the
    prosecution could have responded with “devastating rebuttal” by showing that
    petitioner‟s family was not impoverished and that there was no credible evidence
    that petitioner ever suffered an injury likely to lead to brain damage. But the
    referee did not find that Defense Counsel Skyers should have presented such
    evidence; rather, as explained above, he found that Skyers should have presented
    evidence that petitioner‟s school difficulties resulted from “a low IQ, low
    intellectual functioning, reading and learning difficulties, attention deficits . . . ,
    deficiency in ability to conceptualize, [and] low self esteem.” The Attorney
    General does not mention any “devastating rebuttal” that the prosecution could
    have presented to counter such evidence.
    According to the Attorney General, to the extent evidence about petitioner‟s
    school difficulties required disclosures from petitioner and his family, a
    reasonably competent attorney could not be expected to discover that evidence.
    But we see no reason why Defense Counsel Skyers would have required the
    cooperation of petitioner‟s family to obtain such evidence. Moreover, the
    reluctance of petitioner‟s family to disclose to Skyers the negative aspects of his
    family background may have stemmed from a desire not to say anything that
    might harm petitioner, who, the referee found, was loved by his family. If defense
    counsel had explained to the family that these negative aspects could be beneficial
    to petitioner, it is likely that his family would have been willing to discuss them.
    51
    b. Testimony of petitioner’s mother and sister
    The referee found that “the best practice for trial counsel would have been
    to” call the members of petitioner‟s family at the penalty phase to testify to their
    love for petitioner, and that Gary Jones‟s “recollection as to his childhood
    experience with petitioner should have been presented.” According to the referee,
    “some of the best moments for petitioner at the reference hearing” occurred when
    petitioner‟s mother “described her feelings about her son” and when petitioner‟s
    childhood friend Jones “described his feelings about petitioner.”
    The Attorney General points out that a reviewing court may not resolve a
    claim that a defendant‟s trial counsel was ineffective by determining what would
    have been the “best practice,” because, as the high court has said, “[t]here are
    countless ways to provide effective assistance in any given case” (Strickland v.
    Washington (1984) 
    466 U.S. 668
    , 689) and “a court must indulge a strong
    presumption that counsel‟s conduct falls within the wide range of reasonable
    professional assistance” (ibid.). The Attorney General notes that a reviewing court
    must decide whether the attorney‟s representation “fell below an objective
    standard of reasonableness under prevailing professional norms” (People v. Mai
    (2013) 
    57 Cal.4th 986
    , 1009), not whether the attorney engaged, in the referee‟s
    words, in the “best practice.” But we construe the referee‟s finding in question as
    simply telling this court which portions of the evidence presented at the posttrial
    reference hearing would, in his view, have been useful for presentation by the
    defense at trial. We accept the referee‟s finding for this limited purpose.
    52
    3. Petitioner’s exception to referee’s findings: “No 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 at trial the mitigating evidence
    adduced at the reference hearings; nor were there other
    circumstances which would have led reasonable counsel to not
    present this mitigating evidence.”
    Petitioner asserts that, contrary to the referee‟s findings described above
    (see pt. II.D.1., ante), the prosecution at trial would not have introduced any
    evidence damaging to him if he had introduced at trial the mitigating evidence he
    presented at the posttrial reference hearing, and there were no other circumstances
    that would have caused a reasonable counsel not to present that evidence. As
    explained below, we disagree.
    Petitioner argues that the prosecution at trial would not have presented any
    evidence in rebuttal if trial counsel had presented an alibi defense to the Taylor
    crimes. Petitioner accepts the referee‟s finding that petitioner‟s three crucial alibi
    witnesses (Marcus Player, Earl Bogans, and Wayne Harris) were problematic for
    the defense because they, like petitioner, were members of the Raymond Avenue
    Crips street gang, and because their testimony contradicted that of petitioner‟s.
    Petitioner insists, however, that an alibi defense could have been presented based
    on his own testimony and the “corroborating reference hearing testimony of law
    enforcement officers.” Not so. The officers did not corroborate petitioner‟s
    testimony that he was at home at the time of the Taylor crimes, and they did not
    corroborate his testimony that he was not in the brown Buick car. Such
    corroboration could only have come from witnesses Player, Bogans, and Harris,
    all of whom, the referee found, lacked credibility. (See pt. II.B.1, ante.)
    Petitioner argues that even if the referee is correct that if the defense at trial
    had called alibi witnesses Player, Bogans, and Harris to testify, the prosecution
    could have used these defense witnesses to corroborate its claim that petitioner
    53
    was a member of the Raymond Avenue Crips street gang, the harm to petitioner
    that would have resulted from the prosecutor‟s use of the witnesses in this fashion
    was minor compared to the risk that the jury would find that petitioner was one of
    the perpetrators of the Taylor crimes. If Player, Bogans, and Harris could have
    given persuasive testimony that petitioner was innocent of the Taylor crimes, we
    agree with petitioner that the defense should have presented that testimony, even if
    the jury would have also heard additional evidence that petitioner was a member
    of the Raymond Avenue Crips street gang. But, as the referee found, the
    testimony of petitioner‟s alibi witnesses was not credible.
    According to petitioner, the referee made a finding that if petitioner had at
    trial presented an alibi defense pertaining to the Taylor crimes, the prosecutor
    might have called Evan Mallet, who had been convicted of committing those
    crimes, to testify in rebuttal. Petitioner disagrees with this alleged finding,
    asserting that “no reasonable prosecutor would have called Mallet.” We agree
    with petitioner that it is highly unlikely that the prosecution would have called
    Mallet to testify, but we discern no contrary finding by the referee: No mention of
    Mallet appears in the referee‟s summary of the rebuttal evidence that the
    prosecution could have presented at trial, and the pages of the referee‟s report
    from which petitioner perceives such a finding merely describe Attorney Earley‟s
    posttrial reference hearing testimony when he was cross-examined about the
    possibility that the prosecution might have called Mallet to testify at trial.
    The referee found that if at trial the defense had presented evidence of
    petitioner‟s potential for institutional adjustment if sentenced to life imprisonment
    without possibility of parole, the prosecution could have countered with evidence
    that, while at CYA, petitioner led a race-based riot and assaulted another inmate.
    Petitioner asserts that the CYA misconduct was insignificant because it occurred
    early in his confinement at CYA, and that his behavior at CYA improved over
    54
    time. According to petitioner, even if the prosecutor had introduced evidence that
    petitioner “was not 100% successful at CYA,” the defense could have countered
    that testimony with expert witnesses of its own. But petitioner‟s argument does
    not show that the referee was wrong in finding that if at trial the defense had
    introduced evidence that petitioner would adjust well to incarceration, the
    prosecution could have countered this with evidence of petitioner‟s misconduct at
    CYA.
    With regard to petitioner‟s upbringing and social history, petitioner
    disagrees with the referee‟s finding that if he had presented evidence at trial that as
    a child he suffered from poverty, malnutrition, and physical abuse by his siblings,
    the prosecution could have rebutted this evidence with testimony to the contrary
    from petitioner‟s alibi witnesses (Harris, Bogans, and Player) and petitioner‟s
    childhood friend (Gary Jones). Petitioner asserts that “it is highly unlikely that the
    prosecutor would have called [these witnesses] to testify as to petitioner‟s
    upbringing.” We agree with petitioner that the prosecutor at trial would not have
    initiated calling those witnesses himself. But that is not what the referee found.
    Rather, the referee explained that had the defense called these witnesses to testify
    at trial, the prosecutor might have questioned them on cross-examination about the
    circumstances of petitioner‟s upbringing, much as the Attorney General did at the
    posttrial reference hearing. We perceive no error in the referee‟s finding.
    Petitioner challenges as “ludicrous” the referee‟s finding that at trial the
    prosecution could have presented a statement of petitioner‟s mother to school
    authorities that petitioner‟s birth was normal (if the defense had claimed that
    petitioner suffered brain damage from fetal abuse), and her statement to CYA
    authorities that all was well at home as well as petitioner‟s statement to CYA
    authorities that he had no major problems at home (if the defense had claimed that
    petitioner was abused by his siblings). We agree with the referee that at trial the
    55
    prosecution could have used these statements by petitioner and his mother to
    refute a defense penalty phase claim that petitioner suffered fetal brain damage or
    that he was physically abused at home.
    E. Did petitioner do or say anything to hinder or prevent the
    investigation or presentation of mitigating evidence at the penalty
    phase, or did he ask that any such evidence not be presented? If so,
    what did he do or say?
    The referee found that petitioner did nothing to hinder or prevent the
    investigation of mitigating evidence at the penalty phase of trial, and that he did
    not ask that any such evidence not be presented. Neither party takes exception to
    these findings.
    III. DISCUSSION
    Because a habeas corpus petition is a collateral attack on a presumptively
    valid judgment, “ „the petitioner bears a heavy burden initially to plead sufficient
    grounds for relief, and then later to prove them.‟ ” (In re Price, 
    supra,
     
    51 Cal.4th 547
    , 559.) Even when, as here, this court finds that a habeas corpus petition states
    a prima facie showing that the petitioner is entitled to relief, the petitioner must
    still “ „prove, by a preponderance of the evidence, facts that establish a basis for
    relief on habeas corpus.‟ ” (In re Cudjo (1999) 
    20 Cal.4th 673
    , 687; see also In re
    Bacigalupo (2012) 
    55 Cal.4th 312
    , 333.) “Because the referee observes the
    demeanor of the witnesses as they testify, we generally defer to the referee‟s
    factual findings and „give great weight‟ to them when supported by substantial
    evidence.” (Bacigalupo, supra, at p. 333.)
    Petitioner here claims that defense counsel‟s performance at the penalty
    phase of trial violated petitioner‟s right, under both the federal Constitution‟s Sixth
    Amendment and the California Constitution‟s article I, section 15, to the effective
    assistance of counsel. To obtain relief, he “must prove „ “that counsel‟s
    representation fell below an objective standard of reasonableness under prevailing
    56
    professional norms, and that counsel‟s deficient performance was prejudicial, i.e.,
    that a reasonable probability exists that, but for counsel‟s failings, the result would
    have been more favorable to the defendant.” ‟ ” (In re Crew (2011) 
    52 Cal.4th 126
    , 150.) A reasonable probability, the high court has said, “is a probability
    sufficient to undermine confidence in the outcome.” (Strickland v. Washington,
    
    supra,
     
    466 U.S. 668
    , 694.)
    As we have already explained, we agree with the referee that Defense
    Counsel Skyers was not incompetent at trial for not retaining a neuropsychologist
    to investigate the possibility that petitioner had neuropsychological deficits (see pt.
    II.B.3.a., ante), that petitioner has not shown that Skyers could have discovered
    that Robert Simms‟s fingerprints were found at the Taylor home (see pt. II.B.2.c.,
    ante), and that alibi witness Marcus Player (who was facing a murder charge at the
    time of petitioner‟s trial) would not have talked to a defense investigator and thus
    could not have been used by the defense at trial (see pt. II.B.2.b., ante). We must
    now decide whether, based on the remaining evidence that petitioner presented at
    the posttrial reference hearing, petitioner is entitled to relief.
    Pertinent here is this observation by the United States Supreme Court: “[A]
    court need not determine whether counsel‟s performance was deficient before
    examining the prejudice suffered by the defendant as a result of the alleged
    deficiencies. . . . If it is easier to dispose of an ineffectiveness claim on the ground
    of lack of sufficient prejudice, which we expect will often be so, that course
    should be followed.” (Strickland v. Washington, 
    supra,
     
    466 U.S. 668
    , 697.) Here,
    as in the case of the attorney who represented petitioner‟s codefendant, Craig
    Anthony Ross (see In re Ross (1995) 
    10 Cal.4th 184
    , 204 (Ross)), we need not
    decide whether Defense Counsel Skyers competently represented petitioner at
    trial, because any inadequacy did not prejudice petitioner. Our reasons follow.
    57
    We first consider the evidence that, according to petitioner, Defense
    Counsel Skyers should have discovered and presented in response to the
    aggravating evidence presented by the prosecution. Significantly, none of this
    evidence pertained to the circumstances of the murders of Bobby and Eric Hassan
    of which petitioner was convicted. Those murders were egregious: The victims,
    one of them a 14-year-old handicapped boy, were each shot in the head,
    execution-style, while lying on a bed. Nor did petitioner present any mitigating
    evidence pertaining to the robbery and the aggravated assault that he committed as
    a juvenile, as to which the prosecution presented aggravating evidence at the
    penalty phase of petitioner‟s trial. In the latter offense, petitioner personally
    displayed callousness and brutality, kicking the victim and cutting him with a
    knife.
    As to the Taylor crimes, petitioner could have presented an alibi defense at
    trial. But the referee found the testimony by petitioner‟s alibi witnesses not
    credible, a finding with which we agree. Furthermore, had their testimony been
    presented at trial, it would have contradicted the guilt phase testimony of
    petitioner and his mother that petitioner was at home when the Taylor crimes were
    committed, and it would have contradicted petitioner‟s trial testimony that he was
    not a member of the Raymond Avenue Crips. Thus, there is not a reasonable
    probability that the outcome of the penalty phase of petitioner‟s capital trial would
    have been different had defense counsel presented that evidence.
    We now consider the evidence pertaining to petitioner‟s social history,
    development, and functioning. We begin by summarizing the evidence presented
    at the posttrial reference hearing.
    Through testimony by petitioner‟s mother and uncle, by three of
    petitioner‟s sisters, by his childhood friend Gary Jones, and by psychologist
    Deborah Miora, petitioner presented this evidence at the reference hearing:
    58
    Petitioner was born on August 26, 1962. His father, Lewis Champion II,
    verbally and physically abused petitioner‟s mother, Azell Champion. When Azell
    became pregnant with petitioner, Lewis II said he did not want any more children,
    and he repeatedly hit and kicked Azell to try to kill the fetus.
    Shortly before petitioner‟s birth, his parents separated, and within a few
    months Azell became involved with Gerald Trabue, Sr.; the couple later had two
    children. Trabue, who owned an electronics business, was a good provider and
    was kind to Azell‟s children. But when petitioner was six years old, the family car
    was hit by a driver who ran a red light. Everyone in the family car was hurt;
    Trabue‟s injuries were so serious that he died two weeks later. Petitioner broke
    his collarbone and suffered a head injury. His mother became depressed after
    Trabue‟s death.
    Within a year after Trabue‟s death, Azell married Henry Robinson, with
    whom she had another child, but the marriage lasted less than a year. Thereafter,
    petitioner had no adult male figure in the home.
    After Trabue‟s death, Azell worked outside the home to support her family,
    and she was unable to look after the children during the day. 4 Petitioner‟s sister
    Linda and his brother, Lewis III (six years older than petitioner), cared for the
    younger children. Lewis III hit the other children with belts and an extension
    cord, resulting in calls to the police. When Lewis III was 16 years old, he entered
    the Job Corps for four to seven months. After he returned, he began using
    phencyclidine (PCP), and the frequency and severity of his physical abuse of the
    4      The two children of Azell and Trabue received money from the settlement
    of a wrongful death action filed on their behalf after Trabue‟s death. Azell
    received no money in the action, apparently because she and Trabue were
    unmarried. She did, however, receive an unspecified amount of money as benefits
    from a policy insuring Trabue‟s life.
    59
    younger children, including petitioner, increased. He destroyed family pictures
    and furniture, put holes in the wall, and knocked out windows. On several
    occasions, the police took him to the state mental hospital in Norwalk for
    observation, after which he was released.
    Petitioner‟s second oldest brother, Reginald, was a disturbed child who,
    after he grew up, was diagnosed with schizophrenia and bipolar mood disorder,
    and ended up in prison for shooting his brother-in-law. He also assaulted
    petitioner when they were children.
    Petitioner grew up in South Central Los Angeles. He was teased because
    his skin was very dark and his clothes were old, and he had low self-esteem. He
    performed poorly in elementary school, and his school reports mention that he was
    distracted by problems at home.
    At the age of 15 years, after participating in the robbery of three persons at
    a Greyhound Bus depot, petitioner was committed to a camp. The next year, after
    petitioner assaulted Jose Bustos with a knife (see pp. 4-5, ante), the juvenile court
    committed him to CYA. The Hassan murders occurred two months after his
    release on parole.
    Petitioner contends that if defense counsel at trial had presented the
    evidence described above, there is a reasonable probability that the jury would not
    have imposed a death sentence at the penalty phase of petitioner‟s capital trial.
    We disagree. The referee found that the testimony at the posttrial reference
    hearing that petitioner grew up in extreme poverty was not credible (see pt. II.B.1,
    ante), and he found that the reference hearing testimony that petitioner was beaten
    by his older brothers was “not true,” although he found that petitioner‟s brother
    Lewis‟s attempts to discipline petitioner may at times have been “inappropriate.”
    And if the defense at trial had called petitioner‟s reference hearing witnesses
    Harris and Bogans to give alibi testimony for the Taylor crimes, or if it had called
    60
    petitioner‟s friend Gary Jones to testify about petitioner‟s good character as a
    child, the prosecution at trial could have used these witnesses to rebut the evidence
    of poverty and abuse.
    Petitioner argues that the jury at his capital trial might have credited the
    posttrial reference hearing testimony by members of his family that he was
    physically abused by his oldest brother Lewis, if defense counsel had presented
    such testimony at the penalty phase of his trial. Pertinent here is this court‟s
    decision in Ross, 
    supra,
     
    10 Cal.4th 184
    . In Ross, petitioner‟s codefendant, Craig
    Ross, claimed his attorney was incompetent for not presenting mitigating evidence
    at the penalty phase. At Ross‟s posttrial habeas corpus reference hearing, he
    presented evidence of physical abuse as a child by his stepfather, and he argued
    that his trial attorney should have presented this evidence at the penalty phase of
    trial. This court found that if Ross‟s trial attorney had done so, the prosecution
    could have rebutted it with “a psychiatric report prepared when [Ross] was 15
    years old,” stating that Ross had told the psychiatrist that “he liked and got along
    well with” his stepfather, who had not abused him. (Id. at p. 206.) Similarly, if
    petitioner‟s mother had testified at the penalty phase that petitioner had been
    physically abused by his brothers as a child, the prosecution could have responded
    with evidence that (1) petitioner‟s mother had told a CYA parole officer that her
    children “all relate[d] well to each other, respect[ed] the parent, and [were] helpful
    at home” and that the family was “normal in all respects”; and that (2) petitioner
    had told a CYA psychiatrist he had a “regular family” with “the usual sibling
    rivalry” and his family relationships were not a “major problem.”
    Petitioner asserts that reasonable jurors could well have concluded that his
    “development and functioning [were] adversely affected by living in a community
    plagued by violence.” He notes that he “was not raised in a reasonably safe,
    relatively affluent community with good schools, by people with the advantages of
    61
    education, steady employment, sound mental health, and access to resources . . . .”
    He contends that “[a] reasonable juror could decide that children being beaten by
    persons from rival neighborhoods, gunfire in the streets, and the perception . . .
    that the police were not on one‟s side represents a very substantial set of obstacles
    to healthy development.” But this can also be said of codefendant Ross, who grew
    up in the same neighborhood and who, at his own reference hearing, presented
    testimony that he “lived in a violent neighborhood [and] that his failure to be
    rehabilitated was partly the fault of institutional authorities.” (Ross, 
    supra,
     10
    Cal.4th at p. 205.) This court held that Ross was not prejudiced by his attorney‟s
    failure to present this evidence at trial. (Id. at p. 213.)
    The remaining evidence presented by petitioner at the posttrial reference
    hearing paints the picture of a childhood that was marred by tragedy (the death of
    Gerald Trabue, Sr., petitioner‟s stepfather), after which petitioner‟s mother
    struggled financially. And petitioner struggled with the challenges of a below-
    average intelligence, reading and learning difficulties, and attention deficits. None
    of the evidence, however, was so weighty that it was likely to affect the trial jury‟s
    determination that the brutal Hassan murders committed by petitioner and his
    confederates, when combined with petitioner‟s prior history of robbery and
    aggravated assault, warranted the death penalty.
    In Ross, this court held that defense counsel‟s failure at trial to present, at
    the penalty phase of trial, certain evidence comparable to the evidence in question
    here on behalf of Ross (petitioner‟s codefendant) did not prejudice Ross. The
    decision noted that Ross participated in “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.” (Ross, supra, 10 Cal.4th at p. 213.) The killings were “gang-
    conducted robbery murders, not sudden explosions of angry violence or
    psychopathic serial killings.” (Ibid.) The same can be said of petitioner here.
    62
    And, as this court observed in Ross: “Although 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.” (Ibid.)
    CONCLUSION AND DISPOSITION
    Because our order to show cause and reference order were limited to the
    claim of ineffective assistance of counsel at the penalty phase of petitioner‟s
    capital trial, we do not address any other claim raised in the petition for writ of
    habeas corpus. The remaining claims will be resolved by a separately filed order.
    (See In re Boyette (2013) 
    56 Cal.4th 866
    , 898.)
    The order to show cause is discharged.
    KENNARD, J.*
    WE CONCUR:
    CANTIL-SAKAUYE, C. J.
    BAXTER, J.
    WERDEGAR, J.
    CHIN, J.
    CORRIGAN, J.
    LIU, J.
    *      Retired Associate Justice of the Supreme Court, assigned by the Chief
    Justice pursuant to article VI, section 6 of the California Constitution.
    63
    See next page for addresses and telephone numbers for counsel who argued in Supreme Court.
    Name of Opinion In re Champion
    __________________________________________________________________________________
    Unpublished Opinion
    Original Appeal
    Original Proceeding XXX
    Review Granted
    Rehearing Granted
    __________________________________________________________________________________
    Opinion No. S065575
    Date Filed: April 14, 2014
    __________________________________________________________________________________
    Court: Superior
    County: Los Angeles
    Judge: Francisco P. Briseno, Referee
    __________________________________________________________________________________
    Counsel:
    Karen Kelly, under appointment by the Supreme Court, for Petitioner Steve Allen Champion.
    Bill Lockyer, Edmund G. Brown, Jr., and Kamala D. Harris, Attorneys General, Robert R. Anderson and
    Dane R. Gillette, Chief Assistant Attorneys General, Pamela C. Hamanaka, Assistant Attorney General,
    Sharlene A. Honnaka, Robert S. Henry and Steven E. Mercer, Deputy Attorneys General, for Respondent
    State of California.
    Counsel who argued in Supreme Court (not intended for publication with opinion):
    Karen Kelly
    P.O. Box 6308
    Modesto, CA 95357
    (209) 552-0988
    Steven E. Mercer
    Deputy Attorney General
    300 South Spring Street, Suite 1702
    Los Angeles, CA 90013
    (213) 576-1344