                                           Volume 1 of 2

                 FOR PUBLICATION
 UNITED STATES COURT OF APPEALS
      FOR THE NINTH CIRCUIT

MICHAEL ALLEN HAMILTON,                  No. 06-99008
             Petitioner-Appellant,          D.C. No.
               v.                       CV-F-90-00363-
ROBERT L. AYERS,                            OWW-P
            Respondent-Appellee.
                                          OPINION

       Appeal from the United States District Court
           for the Eastern District of California
       Oliver W. Wanger, District Judge, Presiding

                  Argued and Submitted
          January 20, 2009—Pasadena, California

                Filed September 18, 2009

 Before: Kim McLane Wardlaw, William A. Fletcher, and
            Richard A. Paez, Circuit Judges.

                Opinion by Judge Wardlaw




                          13575
                          HAMILTON v. AYERS                         13581


                              COUNSEL

Katherine L. Hart, Law Offices of Katherine L. Hart, Fresno,
California; Saor E. Stetler, Law Offices of Saor E. Stetler,
Mill Valley, California, for petitioner Michael Allen Hamil-
ton.

Catherine Chatman, Deputy Attorney General, Office of the
California Attorney General, Sacramento, California, for
respondent Robert L. Ayers.


                              OPINION

WARDLAW, Circuit Judge:

   Michael Allen Hamilton, a California death row inmate,
appeals from the district court’s denial of his pre-AEDPA
petition for a writ of habeas corpus challenging his 1982 con-
viction and death penalty sentence for multiple counts of first-
degree murder. We deny Hamilton’s claims for relief as to the
guilt phase. However, we conclude that Hamilton’s trial coun-
sel was constitutionally ineffective at the penalty phase for
failing to investigate and present to the jury the wealth of
classic mitigating evidence that was available to him. Accord-
ingly, we reverse and remand for issuance of the writ, unless
the State elects to reprosecute the penalty phase.1 Because we




  1
   If the State opts against pursuing further penalty phase proceedings,
Hamilton will automatically receive a sentence of life imprisonment with-
out the possibility of parole. See Cal. Penal Code § 190.2 (West 1978); see
also Belmontes v. Ayers, 529 F.3d 834, 837 n.1 (9th Cir. 2008).
13582                  HAMILTON v. AYERS
grant relief based on the ineffective assistance claim, we do
not reach Hamilton’s claim of prosecutorial misconduct at the
penalty phase.

 I.   FACTUAL AND PROCEDURAL BACKGROUND

  We recite verbatim the district court’s statement of facts,
which closely tracks the California Supreme Court’s opinion,
see People v. Hamilton, 774 P.2d 730, 733-35 (Cal. 1989),
and which neither party disputes.

      In 1981, Hamilton, his wife Gwendolyn (Gwen) who
      was pregnant, and their four children, ages six, four,
      three and one, lived in Bakersfield. In March of that
      year, the Hamiltons purchased life insurance poli-
      cies, $175,000 on Hamilton and $100,000 on Gwen,
      paying the initial premium for coverage until June.
      When they did not pay the second quarterly payment
      on time, the agent personally collected the payment
      from Hamilton, extending the policy into September.
      When the third premium was not received, the agent
      again visited the Hamiltons on October 17, collect-
      ing payment for two months from Gwen, extending
      the policies into November.

         In September, Hamilton began an extramarital
      relationship with Brenda Burns. In October, he cal-
      led his sister Carolyn Hamilton to ask if she knew
      anyone who would do something illegal for money.
      Later he told Carolyn he wanted someone to kill
      Gwen and offered her $20,000 from the insurance on
      Gwen’s life if she would help find someone to do the
      killing. Hamilton told both Carolyn and his brother-
      in-law Lyle Palmer that he had a girlfriend, but if he
      left or divorced Gwen he wouldn’t have his kids.
      Brenda’s sister Sharon Burns also testified that Ham-
      ilton told her he didn’t like the way Gwen was in
                  HAMILTON v. AYERS                  13583
bed, sexually, and he wanted to divorce her so he
could live with Brenda.

   Carolyn first asked another sister, Victoria (Vicki)
Hamilton, who agreed to kill Gwen for $10,000 of
the insurance money. However, Vicki moved to
Texas a few days later. Carolyn then approached
Gilbert Garay, a prior acquaintance she met when
both worked as security guards for Porterville Pri-
vate Patrol. Gilbert agreed to kill Gwen for $10,000.

   On October 31, Hamilton and Brenda Burns went
to K-Mart in Bakersfield and purchased a single-shot
12-gauge shotgun. Hamilton said he left his identifi-
cation in the car, so Brenda purchased the gun and
shells with money furnished by Hamilton.

   That evening Hamilton, Gwen, and their children
drove to Porterville to take their kids trick-or-
treating with Carolyn’s son. While accompanying
the children trick-or-treating, Hamilton, Carolyn and
Gilbert discussed plans for the murder. Hamilton
told Carolyn he would start to drive his family home,
but then stop on Highway 65 claiming one tire was
flat, so that Carolyn and Gilbert could drive by and
shoot Gwen. Carolyn and Gilbert left in Carolyn’s
truck a few minutes after Hamilton. As planned, Car-
olyn and Gilbert found Hamilton crouched down by
the tire with Gwen standing beside him holding a
flashlight. Although Carolyn drove by three to four
times, Gilbert never pulled the trigger, so they even-
tually returned to Porterville.

   Hamilton phoned Carolyn about an hour later to
ask what happened. Carolyn made excuses and Ham-
ilton said they would come back to Porterville the
next day. The next day, Hamilton phoned Carolyn to
say he would pretend to have lost his wallet while
13584                 HAMILTON v. AYERS
    changing the tire. Hamilton and Gwen would stop at
    the same place on the pretext of looking for his wal-
    let. Carolyn and Gilbert would follow them and
    shoot Gwen as previously planned.

       That evening, Hamilton and his family again vis-
    ited Carolyn, his mother and stepfather, Jacqueline
    (Jackie) and Sam Piper, in Porterville. Carolyn and
    Gilbert followed Hamilton about a half-hour after he
    left, and found him and Gwen at the same place,
    looking for the “lost” wallet. Carolyn and Gilbert
    drove by several times, but again Gilbert did not
    shoot. Hamilton was mad when he called Carolyn
    about an hour later, and she made more excuses.

       The following day Hamilton called Carolyn with
    a new plan. As part of this plan, Carolyn called
    Gwen and told her that Hamilton’s wallet had been
    found. Hamilton and Gwen for the first time left
    their children with Gwen’s sister, who also lived in
    Bakersfield, and drove a white pickup truck to Por-
    terville. When they arrived, Hamilton surreptitiously
    gave Carolyn his wallet, so she could return it to him
    in front of the family. Hamilton and Carolyn went to
    pick up Gilbert, and Carolyn and Gilbert told Hamil-
    ton they weren’t going to shoot Gwen. Hamilton said
    he would do it. Hamilton said he would be hitchhik-
    ing, and instructed Carolyn and Gilbert to pick him
    up and take him back to his pickup.

       This time everything went according to the new
    plan. Carolyn gave Hamilton an icepick, which he
    used to jab a hole in one of his pickup’s tires. Hamil-
    ton stopped the pickup along the highway because
    one tire was going flat. He left Gwen in the truck and
    walked along the highway, ostensibly to find a place
    where he could phone for help. Carolyn and Gilbert
    picked him up in Carolyn’s truck and drove him to
                  HAMILTON v. AYERS                  13585
a phone booth, where Hamilton called his mother
and asked her to come help him. Mrs. Piper said she
could not come until Carolyn returned with the
truck. Carolyn and Gilbert then drove Hamilton back
to where Gwen was waiting in the pickup. Hamilton
took the shotgun, walked over to the pickup, and
shot Gwen. He returned to the truck and demanded
another shell. After reloading, he went back and shot
Gwen again.

   Gilbert drove back to the phone booth where they
left Hamilton. Carolyn returned home with the truck
after she dropped Gilbert off at a friend’s house. Car-
olyn called Hamilton back at the phone booth and
said their mother and stepfather were on the way.
The Pipers drove Carolyn’s truck to pick up Hamil-
ton at the phone booth, and then to where Hamilton
“discovered” that Gwen had been killed.

   An autopsy revealed the cause of Gwen’s death
was shotgun wounds to the throat and chest, fired at
close range. The fetus was viable and died from
anoxia caused by Gwen’s death.

   Hamilton first told the police that Gwen had been
killed while he was hitch-hiking [sic] to the phone
booth. The next day, however, he said that she was
killed by a Canadian whom he refused to identify.
Eventually Vicki told the police of the plan to kill
Gwen. With Vicki’s consent, the police taped two
phone calls between her and Carolyn. Carolyn and
Gilbert each confessed when they were arrested, and
were each charged with two counts of first degree
murder with special circumstances. Both Carolyn
and Gilbert agreed to plead guilty to second degree
murder with a dangerous-weapon enhancement, and
be sentenced to 16 years to life, in return for their
testimony against Hamilton at trial. Carolyn and Gil-
13586                 HAMILTON v. AYERS
    bert both testified at trial, identifying Hamilton as
    Gwen’s killer.

       At trial, the defense attempted to show that Gilbert
    might have been the actual killer. Lilly Bardsley, the
    clerk from K-Mart who testified for the prosecution
    that she sold the shotgun to Brenda and Hamilton,
    was recalled by the defense and testified instead that
    she sold the gun to Brenda’s sister Sharon, who was
    accompanied by both Hamilton and Gilbert. Sharon,
    also recalled by the prosecution in rebuttal, denied
    purchasing the shotgun. The ATF form filled out at
    the time the gun was purchased was signed with
    Brenda’s name, and the prosecutor presented expert
    testimony that the signature was in Brenda’s, not
    Sharon’s, handwriting. Vicki testified that when she
    first talked to Carolyn after the murder, she assumed
    Gilbert was the shooter. Another defense witness tes-
    tified that prior to Gwen’s murder, Hamilton told her
    he suspected Vicki and her boyfriend, Stephen Fitz-
    herbert (who was Canadian), were planning to kill
    him. Hamilton stated, “Well, you know my family,
    if they want anything bad enough, they’ll kill for it.”
    Hamilton did not testify.

       The jury found Hamilton guilty as charged, and
    found true the charged special circumstances of
    intentional murder for financial gain, and two counts
    of multiple murder. The penalty trial was brief. The
    prosecutor presented documentary evidence that ten
    years previously Hamilton was convicted of grand
    theft. Defense counsel called Hamilton’s mother,
    who testified that as a child Hamilton had been
    removed from the family home because of abusive
    conduct by his father, and placed in a series of foster
    homes. Hamilton requested permission to read a
    statement telling the penalty jury he was not guilty,
    but for unspecified reasons beyond his control he
                      HAMILTON v. AYERS                    13587
    was not permitted to testify or present exonerating
    evidence, and asking the jury to “return with the pen-
    alty described by law for the crime that you have me
    guilty of.” Defense counsel objected, and the court
    refused to permit Hamilton to read the statement.
    After approximately four hours, the jury returned a
    verdict imposing the death penalty.

Hamilton v. Ayers, 458 F. Supp. 2d 1075, 1086-89 (E.D. Cal.
2006) (citations omitted).

   On direct appeal, the California Supreme Court modified
the judgment to set aside one of the multiple-murder special
circumstances but otherwise affirmed Hamilton’s conviction
and sentence, Hamilton, 774 P.2d at 758, and denied his peti-
tion for rehearing. The U.S. Supreme Court denied certiorari.
Hamilton v. California, 494 U.S. 1039 (1990).

   In June 1991, Hamilton filed a habeas petition in the United
States District Court for the Eastern District of California. The
district court instructed him to exhaust his state court reme-
dies. Hamilton then filed a habeas petition in the California
Supreme Court in July 1994. Following a two-day evidentiary
hearing on an allegation of juror misconduct, the California
Supreme Court found that no misconduct had occurred, and
summarily rejected Hamilton’s other claims. In re Hamilton,
975 P.2d 600 (Cal. 1999).

   Hamilton filed an amended federal habeas petition in 2000.
He requested an evidentiary hearing, which the district court
granted only as to the issue of ineffective assistance of coun-
sel at the penalty phase. A two-day hearing was held in
December 2003, and reopened in September 2004. On Octo-
ber 30, 2006, the district court denied Hamilton’s habeas peti-
tion in full. Hamilton, 458 F. Supp. 2d at 1152. Hamilton
13588                    HAMILTON v. AYERS
timely appeals from the district court’s denial of his habeas peti-
tion.2

 II.    JURISDICTION AND STANDARD OF REVIEW

  The district court had jurisdiction to entertain Hamilton’s
habeas petition under 28 U.S.C. § 2254. We have jurisdiction
over Hamilton’s appeal under 28 U.S.C. § 2253.

   Because Hamilton’s first federal habeas petition was filed
before the effective date of the Antiterrorism and Effective
Death Penalty Act of 1996 (“AEDPA”), pre-AEDPA stan-
dards apply to his claims. See Correll v. Ryan, 539 F.3d 938,
941-42 (9th Cir. 2008). We review de novo the district court’s
denial of habeas relief, Raley v. Ylst, 470 F.3d 792, 799 (9th
Cir. 2006), but review for clear error the district court’s fac-
tual findings, Frierson v. Woodford, 463 F.3d 982, 988 (9th
Cir. 2006). “Although less deference to state court factual
findings is required under the pre-AEDPA law . . ., such fac-
tual findings are nonetheless entitled to a presumption of cor-
rectness unless they are not fairly supported by the record.”
Silva v. Woodford, 279 F.3d 825, 835 (9th Cir. 2002) (citing
to 28 U.S.C. § 2254(d)(8)) (internal quotation marks omitted).

   We also review de novo “mixed questions of law and fact,
whether decided by the district court or the state courts.”
Jackson v. Brown, 513 F.3d 1057, 1069 (9th Cir. 2008)
(Brady/Napue claim); see Fields v. Brown, 503 F.3d 755, 770
(9th Cir. 2007) (en banc) (juror bias claim); Frierson, 463
F.3d at 988 (ineffective assistance of counsel claim).
  2
    The district court granted a Certificate of Appealability (“COA”) on
Hamilton’s Brady/Napue and ineffective assistance of counsel claims. We
granted Hamilton’s motion to broaden the COA to include his prosecu-
torial and juror misconduct claims. See Slack v. McDaniel, 529 U.S. 473,
482-84 (2000).
                      HAMILTON v. AYERS                   13589
                     III.   DISCUSSION

A.   Guilt Phase Claims

1.   Juror Bias

   Hamilton challenges his conviction on grounds of juror bias
and misconduct. His allegations stem from a declaration pre-
pared by investigators from the California Appellate Project
(“CAP”) in 1994, which juror Geneva Gholston signed. The
1994 declaration stated that (1) before trial, Gholston dis-
cussed with a neighbor Hamilton’s “ridiculous” story that a
Canadian had murdered his wife, and the two agreed that
Hamilton was guilty; (2) Gholston “prayed” to sit on Hamil-
ton’s jury after the spirit of her deceased Uncle Frank, who
had been a bank robber and killer, exhorted her to atone for
his wrongs; (3) during trial, Gholston saw the “skinnier” of
Hamilton’s sisters watching her from a car in the alley behind
Gholston’s home, which prompted Gholston to request
increased police patrols; and (4) Gholston collected newspa-
per articles about Hamilton during the trial. In re Hamilton,
975 P.2d at 605-06, 617 n.21. “None of these matters had
been brought to the attention of [the] court or counsel at peti-
tioner’s trial.” Id. at 605.

   Responding to the 1994 declaration, the California
Supreme Court ordered the Director of Corrections to show
cause why Hamilton’s conviction and death sentence “should
not be vacated on grounds that Juror Geneva Gholston was
actually biased and/or incompetent when sworn as a juror, and
that she committed prejudicial misconduct by concealing her
bias during the jury selection process.” Id. at 605. In 1996, at
the instigation of the California Attorney General, Gholston
submitted a second declaration, which stated that (1) the CAP
investigators did not identify themselves as working on behalf
of Hamilton; (2) they did not record or take notes of their
interview with Gholston; (3) Gholston did not read or receive
a copy of the 1994 declaration; (4) the 1994 declaration was
13590                 HAMILTON v. AYERS
wrong in several material respects, particularly with regard to
Uncle Frank; and (5) the encounter in the alley did not affect
her participation as a juror. Id. at 605-06.

   Confronted with these conflicting declarations, the Califor-
nia Supreme Court ordered an evidentiary hearing, which
took place in November 1997. At the hearing, Gholston, one
of the CAP investigators, and others testified extensively over
two full days. Id. at 606-12 (summarizing testimony).
Reviewing the evidence presented at the 1997 hearing, the
state court referee concluded that

    (1) petitioner has failed to show by a preponderance
    of evidence that Gholston either harbored or con-
    cealed pretrial bias, (2) any inaccurate responses by
    Gholston on voir dire were inadvertent, not deliber-
    ate, and (3) if Gholston saw petitioner’s sister in the
    alley behind Gholston’s home during the trial, the
    experience did not cause Gholston to prejudge peti-
    tioner’s case.

Id. at 612. The California Supreme Court adopted the refer-
ee’s findings and denied Hamilton’s habeas petition. See id.
at 615-21.

   Hamilton challenges each of these determinations, arguing
primarily that the referee’s findings were erroneous. Gener-
ally, we review de novo the district court’s denial of pre-
AEDPA claims of implied bias in habeas petitions, “because
implied bias is a mixed question of law and fact.” Fields, 503
F.3d at 770. To justify a new trial based on a claim of juror
bias, Hamilton must demonstrate that a dishonest answer was
given on voir dire to a material question and that the correct
response would have provided a valid basis for a challenge for
cause, see McDonough Power Equip., Inc. v. Greenwood, 464
U.S. 548, 556 (1984), or that his right to an impartial jury,
guaranteed by the Sixth and Fourteenth Amendments, was
otherwise violated by actual or implied juror bias, see Fields,
                          HAMILTON v. AYERS                13591
503 F.3d at 766-68; see also Morgan v. Illinois, 504 U.S. 719,
726-27 (1992); Remmer v. United States, 347 U.S. 227, 229
(1954). Hamilton must also surmount the “presumption of
correctness” that we afford to the state courts’ factual conclu-
sions regarding the possibility of prejudicial misconduct. 28
U.S.C. § 2254(e)(1); see Thompson v. Keohane, 516 U.S. 99,
111 (1995) (noting requirement that presumptive weight be
accorded to a trial court’s resolution of factual issues, includ-
ing juror impartiality, because the resolution of such issues
“depends heavily on the trial court’s appraisal of witness
credibility and demeanor”). For the reasons that follow, we
affirm the district court’s rejection of these claims.

  a)         Implied or Concealed Bias

       i.     Pretrial Conversations

   [1] Gholston omitted from her voir dire responses any men-
tion of a pretrial conversation she had with a neighbor regard-
ing Hamilton’s suggestion that a Canadian had murdered his
wife. In answering the voir dire questions, however, Gholston
acknowledged her basic familiarity with the circumstances of
the crime. In fact, when asked whether the material she had
read caused her to form an opinion regarding the guilt or
innocence of the defendant, she answered: “No, it really
didn’t.” Moreover, the record confirms that “Gholston’s omis-
sions on voir dire were inadvertent, not intentional,” and that
“even if Gholston’s voir dire answers understated her pretrial
awareness and impressions about the case, particularly with
respect to petitioner’s claim of a Canadian killer, her omis-
sions did not lead to the seating of a biased juror.” In re Ham-
ilton, 975 P.2d at 616.

       ii.     Newspaper Clippings

   [2] Gholston testified at the 1997 hearing that while her
husband clipped some newspaper articles to be saved for her
sister, she did not personally make any clippings. The Califor-
13592                 HAMILTON v. AYERS
nia Supreme Court noted that the referee did not make a find-
ing regarding whether Gholston actually clipped any articles
during the trial, but concluded that even if such misconduct
had occurred, “any presumption of prejudice is rebutted”
because the “clippings contained mere neutral and even-
handed accounts of the trial.” Id. at 617 n.21. We agree.
Moreover, as the California Supreme Court observed, “[n]o
strong inference of bias arises simply because a juror failed to
resist the temptation to read news articles,” and “[t]here is no
evidence that Gholston discussed these articles with other
jurors or otherwise employed them in her deliberations.” Id.
Therefore, the clippings do not support a claim of implied or
concealed bias.

    iii.   Uncle Frank

   Gholston testified at the 1997 hearing that as she was con-
sidering how to get out of serving on the Hamilton jury, she
experienced a clearing of conscience, or a clearing of the
mind, that led her to conclude that she should not fabricate an
excuse to avoid jury service. In her own words: “it was just
my mind cleared up and I said well, I have no excuse.” At
another point, Gholston testified that Uncle Frank may have
caused her to have this clearing of conscience, but she also
stated that he never spoke to her and she never felt his pres-
ence. Any potential inconsistency in this testimony is easily
resolved through the possibilities that Gholston attributed her
clearing of mind to Uncle Frank after she experienced it, or
that thinking about her uncle triggered her clearing of mind.
Accordingly, the record fairly supports the California
Supreme Court’s finding that Gholston “experienced no direct
encounter with her Uncle Frank’s spirit,” and that the fact that
she in some sense “felt the uncle’s presence, and was thereby
reassured to serve and to render her verdicts, did not cause her
to prejudge the case.” Id. at 618.

    iv.    The 1994 Declaration

  The referee did not resolve the question of whether Ghols-
ton actually reviewed and approved the 1994 declaration pre-
                       HAMILTON v. AYERS                   13593
pared by the CAP investigators, although the referee did
determine, and the California Supreme Court agreed, that the
declaration’s “extreme statements” regarding Uncle Frank did
not “accurately convey the experience Gholston was trying to
describe.” Id.

   [3] Hamilton argues that the enthusiasm with which Ghols-
ton repudiated all signatures and initials attributed to her, even
those from the 1996 declaration prepared by the California
Attorney General, as well as her extreme position that she
never even saw the 1994 declaration, indicates willful decep-
tiveness on Gholston’s part. The scope of Gholston’s repudia-
tion may have been excessive, but her vehemence at the 1997
hearing does not necessarily lead to the conclusion that all of
her testimony should be discredited. Further, while the testi-
mony of CAP investigator Scarlet Nerad did conflict with
Gholston’s testimony, the record demonstrates why the ref-
eree credited Gholston’s testimony over Nerad’s. Specifically,
the 1997 hearing transcript supports the conclusions that (1)
Gholston did not understand the purpose of the investigators’
1994 visits; (2) Gholston did not pay attention to what she
was signing; and (3) Gholston’s 1997 testimony about her
experiences in 1994 and during Hamilton’s trial was generally
reliable, though tinged at times by exaggerated, overemphatic
denials.

   The State accurately distinguishes the cases Hamilton
offers in support of this claim. In Dyer v. Calderon, we
explicitly found not only that “the facts were not properly
developed by the state court,” but also that the potentially
biased juror had “plainly lied” in answering certain questions
and that “no rational trier of fact could find otherwise.” 151
F.3d 970, 979 (9th Cir. 1998) (en banc). Specifically, the juror
stated on voir dire that no member of her family had been the
victim of a homicide, when in fact her brother had been mur-
dered. Id. at 972-73. When questioned during trial about this
omission, she stated she thought the killing was an accident,
although the circumstances of the crime actually confirmed
13594                  HAMILTON v. AYERS
that the killing was deliberate. Id. at 974. Nonetheless, after
a brief in camera hearing, the judge concluded the juror was
not biased. Id. at 975. We disagreed, finding implied bias
where a juror “chose to conceal a very major crime—the kill-
ing of her brother in a way that she knew was very similar to
the way [the petitioner] was accused of killing his victims.”
Id. at 982. In contrast to Dyer, California provided Hamilton
with a two-day evidentiary hearing on the issue of juror mis-
conduct. Further, Gholston’s incomplete voir dire answers
were not “plain lies,” and Hamilton has failed to demonstrate
the necessary “excess of zeal” that led the Dyer panel to infer
the impermissible taint of bias. Id.

   Similarly, in Green v. White, the allegedly biased juror did
not disclose a prior assault conviction. We found it “hard to
imagine that [the juror] could have forgotten about the six
months he spent in the brig for the past assault, no matter how
much time had passed.” 232 F.3d 671, 676 (9th Cir. 2000). In
contrast, it is not hard to imagine that, several months after
briefly discussing the Hamilton murder with a neighbor and
reading about it in multiple newspapers, Gholston only
recalled her primary source of information.

  b)     Actual Bias from the “Encounter”

   [4] So far as the potential impact on Gholston is concerned,
it is irrelevant whether Vicki (the “skinnier” Hamilton sister)
and her fiancé were actually parked in the car that Gholston
saw in the alley behind her home. Aside from conclusory alle-
gations, Hamilton fails to explain how the supposed encounter
engendered bias. In theory, an encounter of this nature could
introduce the “kind of unpredictable factor into the jury room
that the doctrine of implied bias is meant to keep out.” Dyer,
151 F.3d at 982. Nonetheless, Hamilton fails to overcome the
presumption of correctness we accord the state’s findings on
this issue. As the California Supreme Court found:

       The episode described by Gholston was brief, iso-
       lated, and ambiguous. The people Gholston saw
                       HAMILTON v. AYERS                   13595
     parked in her alley did not approach or speak to her.
     Gholston mentioned no display of weapons or threat-
     ening gestures. According to Gholston, the two indi-
     viduals simply sat in their car, and they drove away
     rapidly the instant they realized that Gholston had
     seen them. By Gholston’s own account, “it never
     occurred to [her]” to report the incident to the trial
     court. She further insisted she never discussed the
     incident with other jurors, and there is no contrary
     evidence.

In re Hamilton, 975 P.2d at 621 (alteration in original). We
agree with the California Supreme Court that the “episode
affords no basis for relief,” id., and affirm the district court’s
conclusion that Hamilton has not shown, and the record does
not reveal, that Gholston was biased against him. Cf. United
States v. Armstrong, 654 F.2d 1328, 1333 (9th Cir. 1981)
(finding no abuse of discretion in the district court’s refusal
to declare a mistrial as a result of phone calls received by a
juror’s husband, where the calls “did not refer to the merits,”
“did not articulate threats,” and were not “identified with
either side,” and agreeing with the district court that any
resulting irregularity did not compromise the “essential fair-
ness of the process”).

B.    Brady and Napue Claims

   [5] Hamilton claims that the prosecution suppressed evi-
dence that “could reasonably be taken to put the whole case
in such a different light as to undermine confidence in the ver-
dict.” Kyles v. Whitley, 514 U.S. 419, 435 (1995); see also
Brady v. Maryland, 373 U.S. 83 (1963); Napue v. Illinois, 360
U.S. 264 (1959). Specifically, he argues that the prosecution
withheld evidence of certain terms of Gilbert’s plea agree-
ment and of his personal ties to one of the Sheriff’s detectives
who investigated the case, Detective Jay Salazar; that the
prosecution ordered Gilbert to conform his testimony to a
“scripted” statement and pressured him to “round up” alibi
13596                       HAMILTON v. AYERS
witnesses; and that the prosecution withheld evidence of con-
cessions Vicki received in exchange for her testimony. The
California Supreme Court summarily rejected Hamilton’s
Brady and Napue claims, and the district court denied them
on the merits. The district court also denied Hamilton’s
request for an evidentiary hearing on these claims pursuant to
Townsend v. Sain, 372 U.S. 293, 312 (1963), overruled on
other grounds by Keeney v. Tamayo-Reyes, 504 U.S. 1, 5-6
(1992), and its progeny, see, e.g., Insyxiengmay v. Morgan,
403 F.3d 657, 669-70 (9th Cir. 2005). We agree with the dis-
trict court.

   There are three components to a Brady violation: (1) excul-
patory or impeaching evidence favorable to the accused; (2)
suppressed by the State; (3) resulting in prejudice. Strickler v.
Greene, 527 U.S. 263, 281-82 (1999). To establish prejudice
under Brady, Hamilton must demonstrate a “ ‘reasonable
probability that, had the evidence been disclosed to the
defense, the result of the proceeding would have been differ-
ent.’ ” Id. at 280 (quoting United States v. Bagley, 473 U.S.
667, 682 (1985)). In contrast, where the prosecution presents
or fails to correct false evidence in violation of Napue, we
assess whether there is “ ‘any reasonable likelihood that the
false testimony could have affected the judgment of the
jury.’ ” Jackson, 513 F.3d at 1078 (quoting Hayes v. Brown,
399 F.3d 972, 985 (9th Cir. 2005) (en banc)). “The materiality
of suppressed evidence is ‘considered collectively, not item
by item.’ ” Id. at 1071 (quoting Kyles, 514 U.S. at 436).3 Even
  3
   In Jackson, we described the analytical model for collectively assess-
ing the materiality of Brady and Napue claims:
      Although we must analyze Brady and Napue violations “collec-
      tively,” the difference in the materiality standards poses an ana-
      lytical challenge. The Napue and Brady errors cannot all be
      collectively analyzed under Napue’s “reasonable likelihood”
      standard, as that would overweight the Brady violations. On the
      other hand, they cannot be considered in two separate groups, as
      that would fail to capture their combined effect on our confidence
                          HAMILTON v. AYERS                          13597
viewed collectively, however, the suppressed evidence at
issue does not reveal a reasonable probability that the result
of Hamilton’s trial would have been different. Indeed, com-
pared to the overwhelming evidence of Hamilton’s guilt, the
allegedly suppressed evidence is relatively insignificant.

  First, the jury received ample evidence of the connections
between Gilbert’s family and Detective Salazar. The signifi-
cance of any additional evidence regarding these connections
appears minimal and is unlikely to have altered the jury’s
assessment of the evidence.

   Second, the State convincingly explains that Gilbert was
not forced to conform his testimony to a “scripted” statement.
The prosecution’s treatment of Gilbert subsequent to Lilly
Bardsley’s identification of him as the third participant in the
purchase of the shotgun at K-Mart appears consistent with a
general and unsurprising concern that Gilbert might not have
testified truthfully. Indeed, had Gilbert been unable to confirm
his whereabouts on the Halloween evening the shotgun was
purchased, the prosecution may well have been justified in

    in the jury’s decision. To resolve this conflict, we first consider
    the Napue violations collectively and ask whether there is “any
    reasonable likelihood that the false testimony could have affected
    the judgment of the jury.” Hayes, 399 F.3d at 985 (emphasis
    added). If so, habeas relief must be granted. However, if the
    Napue errors are not material standing alone, we consider all of
    the Napue and Brady violations collectively and ask whether
    “there is a reasonable probability that, but for counsel’s unprofes-
    sional errors, the result of the proceeding would have been differ-
    ent.” Bagley, 473 U.S. at 682, 105 S. Ct. 3375 (emphasis added)
    (internal quotation marks omitted); United States v. Zuno-Arce,
    25 F. Supp. 2d 1087, 1117 (C.D. Cal. 1998) (applying a two-step
    materiality analysis to combined Brady and Napue claims), aff’d,
    339 F.3d 886 (9th Cir. 2003). At both stages, we must ask
    whether the defendant “received . . . a trial resulting in a verdict
    worthy of confidence.” Kyles, 514 U.S. at 434, 115 S. Ct. 1555.
513 F.3d at 1076 (alteration in original).
13598                      HAMILTON v. AYERS
withdrawing the plea agreement, which was conditioned on
Gilbert’s honest and truthful testimony at trial. Because Gil-
bert explained the conditions of his plea agreement in open
court, it is clear that everyone, including the jury, knew full
well that if Gilbert had lied on the stand, he would have vio-
lated the terms of his deal. Thus, as soon as Bardsley identi-
fied Gilbert and thereby controverted his testimony, it would
have been apparent that Gilbert’s plea agreement was imper-
iled. Defense counsel’s failure to examine Gilbert on this
issue cannot be attributed to the prosecution. Moreover, this
situation is markedly distinct from Smith v. Baldwin, in which
the “prosecutor informed [a witness] that if he insisted on tes-
tifying in accordance with his recantations, the state would
seek to set aside his plea agreement in this case, subjecting
[him] to capital murder charges.” 510 F.3d 1127, 1136 (9th
Cir. 2007) (en banc). Unlike the witness in Smith, Gilbert
never attempted to recant his testimony. On the contrary, after
Bardsley testified that Gilbert was present at the shotgun pur-
chase, he simply produced alibi witnesses to confirm his con-
sistent statement that he spent the late afternoon and evening
trick-or-treating.4

   Third, given that Gilbert faced the death penalty in the
absence of his plea agreement, the prosecution’s facilitation
of Gilbert’s release on bond during the trial appears insignifi-
cant. Moreover, Gilbert’s testimony that his release on bail
was not part of the plea agreement appears consistent with the
statement in his declaration that “the prosecutor said he would
not object to the court setting bail, and I accepted the plea bar-
gain.” After all, the court made the ultimate decision regard-
  4
    Hamilton argues that Gilbert’s initial testimony that he was trick-or-
treating with his child is inconsistent with the rebuttal testimony that pro-
vided the details of his excursions. However, Hamilton fails to identify
any actual conflict, pointing at best to minor and unsurprising discrepan-
cies regarding the timing of Gilbert’s activities. Accordingly, the district
court’s factual finding that the “rebuttal witnesses’ testimony was in fact
consistent with Gilbert’s testimony on direct examination” is not clearly
erroneous.
                             HAMILTON v. AYERS                           13599
ing bail, not the prosecution. Regardless, this additional
inducement could not have affected the jury’s scrutiny of Gil-
bert’s testimony, given what the jury already knew about Gil-
bert’s involvement in the murders and the other inducements
he received to testify. Even assuming the prosecution’s failure
to correct this testimony at trial implicated Napue, there does
not appear to be “ ‘any reasonable likelihood that the false
testimony could have affected the judgment of the jury.’ ”
Jackson, 513 F.3d at 1078 (quoting Hayes, 399 F.3d at 985).

   Fourth, while Hamilton argues that the facts are in dispute
as to the threats and inducements provided to Gilbert to elicit
his testimony, it appears that the only real dispute pertains to
the significance of such threats and inducements. To the
extent any factual disputes remain, the resolution of these dis-
putes in Hamilton’s favor does not alter the prejudice analy-
sis.

   Finally, although there is some conflict between Gilbert’s
description of the murders in his 1994 declaration and his trial
testimony that he looked away when the shots were fired,5 the
fact that Gilbert actually watched the shootings is not proba-
tive of who pulled the trigger, and it is undisputed that Gilbert
and Carolyn were present during the murders. As the State
observes, this graphic testimony may have made Gilbert’s tes-
timony even more damaging.
  5
   In a 1994 declaration, Gilbert described the shooting as follows:
      I remember Gwendolyn opening the window part-way, swatting
      away the barrel of the shotgun when it was put through the
      partially-open window, and after the door was opened the blast
      of the first shot knocking her in slow motion back and to the side.
      I can still see her as she fell over, but with her eyes still open and
      staring straight ahead. Then the second shot knocked her further
      over, and as she slumped down her hair was caught in the gun-
      rack and she could not fall any more.
Hamilton argues that Gilbert’s recollection of the shooting, which con-
flicts with his testimony at trial that he looked away when the shots are
fired, shows that Gilbert was the shooter.
13600                 HAMILTON v. AYERS
   [6] Assuming Hamilton has otherwise identified Brady and
Napue violations, he fails to establish that those violations are
material. Cf. Jackson, 513 F.3d at 1075-79. In Jackson, we
found material violations of Napue where the prosecution’s
solicitation of perjured testimony bolstered the credibility of
two “key” witnesses, “whereas the truthful testimony would
have substantially impeached” those witnesses’ credibility. Id.
at 1078. Similarly, in Hayes, in which the “State knowingly
presented false evidence to the jury and made false represen-
tations to the trial judge as to whether the State had agreed not
to prosecute [a lead witness] on his pending felony charges,”
399 F.3d at 978, we also found violations of Napue, reasoning
that the witness’s credibility would have been affected if the
jury had been informed of the “critical deal,” id. at 987.

   Gilbert’s testimony was admittedly critical to the prosecu-
tion’s case against Hamilton. However, in contrast to both
Jackson and Hayes, it is difficult to imagine Gilbert’s credi-
bility being even remotely affected by the correction or clari-
fication of his testimony regarding the prosecution’s
involvement in his release on bail. The same is true of Vicki’s
possibly false testimony regarding additional benefits she and
her fiancé received in exchange for their testimony. Once
again, in light of the benefits of which the jury was already
aware, the additional benefits would have been cumulative
and insignificant. Accordingly, the Napue violations are not
collectively material.

   [7] Similarly, considering all the possible Brady and Napue
violations together, there is no reasonable probability that the
outcome of the guilt phase of Hamilton’s trial would have
been different. The suppressed evidence and possible false-
hoods pertained to the details of collateral matters with which
the jury was well acquainted. Accordingly, because Hamilton
has not shown that his “allegations, if proved, would entitle
him to relief,” an evidentiary hearing on these claims was not
required. Insyxiengmay, 403 F.3d at 670 (internal quotation
marks omitted).
                      HAMILTON v. AYERS                   13601
   The overwhelming evidence of Hamilton’s guilt only
strengthens our conclusion that he was not prejudiced by the
alleged Brady and Napue violations. In light of this evidence,
defense counsel’s failure to prepare effectively for the penalty
phase of Hamilton’s trial is all the more egregious.

C.     Penalty Phase Claims

  Hamilton asserts two penalty phase claims. Because we
grant relief as to Hamilton’s claim of ineffective assistance of
counsel, we do not reach his claim of prosecutorial miscon-
duct.

   To prevail on his claim of ineffective assistance of counsel,
Hamilton must demonstrate that his trial counsel’s penalty
phase performance “fell below an objective standard of rea-
sonableness” at the time of trial, Strickland v. Washington,
466 U.S. 668, 688 (1984), and “that there is a reasonable
probability that, but for counsel’s unprofessional errors, the
result of the proceeding would have been different,” id. at
694.

  1.   Deficient Performance

   Although the Supreme Court “ha[s] declined to articulate
specific guidelines for appropriate attorney conduct and
instead ha[s] emphasized that ‘the proper measure of attorney
performance remains simply reasonableness under prevailing
professional norms,’ ” Wiggins v. Smith, 539 U.S. 510, 521
(2003) (alteration omitted) (quoting Strickland, 466 U.S. at
688), “general principles have emerged regarding the duties
of criminal defense attorneys that inform our view as to the
‘objective standard of reasonableness’ by which we assess
attorney performance, particularly with respect to the duty to
investigate,” Summerlin v. Schriro, 427 F.3d 623, 629 (9th
Cir. 2005) (en banc).

   [8] At the time of Hamilton’s trial, his counsel had a duty
to conduct “a thorough investigation of the defendant’s back-
13602                  HAMILTON v. AYERS
ground.” Williams v. Taylor, 529 U.S. 362, 396 (2000); see
Ainsworth v. Woodford, 268 F.3d 868, 873-74 (9th Cir. 2001).
Because “[t]he Constitution prohibits imposition of the death
penalty without adequate consideration of factors which
might evoke mercy,” Hendricks v. Calderon, 70 F.3d 1032,
1044 (9th Cir. 1995) (citing Deutscher v. Whitley, 884 F.2d
1151, 1152 (9th Cir. 1989)) (internal quotation marks omit-
ted), “[i]t is imperative that all relevant mitigating information
be unearthed for consideration at the capital sentencing
phase,” Caro v. Calderon, 165 F.3d 1223, 1227 (9th Cir.
1999). To that end, trial counsel must inquire into a defen-
dant’s “social background, . . . family abuse, mental impair-
ment, physical health history, and substance abuse history,”
Correll, 539 F.3d at 943; obtain and examine “mental and
physical health records, school records, and criminal records,”
id.; see Summerlin, 427 F.3d at 630; consult with appropriate
medical experts, Mayfield v. Woodford, 270 F.3d 915, 927-28
(9th Cir. 2001) (en banc); and pursue relevant leads, Lam-
bright v. Schriro, 490 F.3d 1103, 1117 (9th Cir. 2007) (per
curiam). Although “we must avoid the temptation to second-
guess [counsel’s] performance or to indulge ‘the distorting
effects of hindsight,’ ” Mayfield, 270 F.3d at 927 (quoting Str-
ickland, 466 U.S. at 689), we need not defer to counsel’s
choices at trial unless “those choices [were] made after coun-
sel . . . conducted reasonable investigations or [made] a rea-
sonable decision that makes particular investigations
unnecessary,” Summerlin, 427 F.3d at 630 (third alteration in
original) (internal quotation marks omitted).

   [9] Counsel also has an obligation to present and explain to
the jury all available mitigating evidence. Correll, 539 F.3d
at 946. Evidence about the defendant’s background and char-
acter is relevant to the jury’s determination “because of the
belief, long held by this society, that defendants who commit
criminal acts that are attributable to a disadvantaged back-
ground, or to emotional and mental problems, may be less
culpable than defendants who have no such excuse.” Boyde v.
California, 494 U.S. 370, 382 (1990) (emphasis and internal
                          HAMILTON v. AYERS                         13603
quotation marks omitted). In a capital case, such evidence can
be the difference between a life sentence and a sentence of
death. See Mak v. Blodgett, 970 F.2d 614, 619 (9th Cir. 1992)
(per curiam) (“[T]he issue for the jury is whether the defen-
dant will live or die . . . . To fail to present important mitigat-
ing evidence in the penalty phase—if there is no risk in doing
so—can be as devastating as a failure to present proof of
innocence in the guilt phase.” (second alteration in original)).

  a)     Penalty Phase Investigation

   What little investigation Hamilton’s counsel did for the
penalty phase was revealed at the evidentiary hearing held
before the district court in December 2003. Hamilton testified
and presented testimony from his defense counsel and Philip
Cherney, an expert on ineffective assistance of counsel
claims. The State presented the testimony of the defense
investigator, Danny Wells.

   Defense counsel testified that Hamilton’s case was the first
capital case on which he had worked. However, counsel did
not retain anyone other than Wells to assist with the penalty
phase preparations. In fact, he never even thought about
retaining a mitigation expert or a mental health expert. More-
over, he did not have the benefit of a more experienced attor-
ney’s advice, as he did not associate co-counsel for
Hamilton’s case.6

   Wells had never previously worked with Hamilton’s coun-
sel. At the time, Wells did not have any training in conducting
an investigation for the penalty phase of a capital case. He
could not specifically recall whether he had worked on any
death penalty cases before Hamilton’s.
   6
     We need not decide whether the failure to associate co-counsel alone
suffices to render counsel’s performance deficient, cf. Mayfield, 270 F.3d
at 927 (citing Keenan v. Superior Court, 640 P.2d 108 (Cal. 1982)), as
counsel’s performance here was deficient without placing this fact into the
mix.
13604                 HAMILTON v. AYERS
   Defense counsel testified that he began working on the pen-
alty phase while preparing for the guilt phase. He acknowl-
edged that Wells did the majority of the investigation for the
guilt and penalty phases. Both defense counsel and Wells tes-
tified that the case file appeared to be incomplete, but neither
could state definitively which, if any, documents were miss-
ing. Defense counsel explained that after the trial ended, he
provided the entire case file to Hamilton’s first appellate
attorney, Betty Dawson. Neither defense counsel nor anyone
in his office made copies of any of the documents before turn-
ing them over to Dawson.

   [10] According to the documents that were included in the
file, the investigation consisted of at most five interviews: (1)
Vicki (Hamilton’s sister); (2) Marvin Hamilton (Hamilton’s
uncle); (3) Patti Ketchum (the foster sister of Hamilton’s sis-
ter Carolyn); (4) Ron Stafford (Carolyn’s then-boyfriend);
and (5) John Stevens (an acquaintance of Carolyn’s). The
interviews took place shortly before jury selection began.
Wells conducted all of the interviews on his own, except
Vicki’s. Defense counsel participated in Vicki’s interview,
during which he and Wells questioned her about Hamilton’s
“past including his childhood,” according to Wells’s notes.
However, the notes from Vicki’s interview in fact do not
mention anything about Hamilton’s childhood. Nor does
Vicki’s declaration in support of Hamilton’s habeas petition
clarify whether she was asked about his childhood during her
interview. In light of Wells’s evidentiary hearing testimony
that if Vicki had relayed information about Hamilton’s child-
hood, he would have included it in his notes, the district
court’s finding that defense counsel and Wells obtained such
information about Hamilton’s childhood from Vicki is clearly
erroneous. As we discuss below, Vicki could have provided
countless details about the physical and mental abuse Hamil-
ton suffered as a child. Counsel thus acted deficiently in fail-
ing to interview this key witness about Hamilton’s childhood
background.
                      HAMILTON v. AYERS                   13605
   [11] That defense counsel did not adequately investigate
the available mitigating evidence is even more apparent in his
response to Well’s interview with Marvin Hamilton, as docu-
mented. As noted above, in 1967 Hamilton was placed with
Marvin after Carolyn disclosed to a relative that her father had
been sexually abusing her for years and that her mother had
acquiesced in the abuse. Wells’s interview notes demonstrate
that Marvin was well aware of the abuse: “[Marvin] said that
[Hamilton’s father, Bob,] was molesting Carolyn and he went
to jail for it and so did thier [sic] mother because she knew
about it and did nothing about it.” Marvin also mentioned that
Hamilton had “mov[ed] from one military base to another”
throughout his childhood. Defense counsel specifically
recalled that he reviewed Wells’s report, but that he did not
ask Wells to investigate further into the alleged abuse or
Bob’s military records. Counsel acted deficiently in failing to
pursue such classic mitigating evidence. See Lambright, 490
F.3d at 1117 (“[W]hen tantalizing indications in the record
suggest that certain mitigating evidence may be available,
those leads must be pursued.” (internal quotation marks omit-
ted)); see also Wiggins, 539 U.S. at 525 (“[A]ny reasonably
competent attorney would have realized that pursuing . . .
leads [regarding the petitioner’s traumatic childhood] was
necessary to making an informed choice among possible
defenses, particularly given the apparent absence of any
aggravating factors in petitioner’s background.”).

   The other three interviews unearthed no information about
Hamilton’s background, which is not surprising, given that
each of them lasted only one to two minutes. Defense counsel
likely never intended to obtain information from these wit-
nesses for purposes of the penalty phase defense, as they
barely knew Hamilton. They were involved in the case only
because of their knowledge of events that occurred shortly
before and after the crime.

  [12] Most of the available witnesses who could have pro-
vided vital information about Hamilton’s background were
13606                  HAMILTON v. AYERS
never contacted by anyone working on Hamilton’s behalf at
the time of trial. The district court thus clearly erred in finding
that either defense counsel or Wells “did interview the avail-
able witnesses, and no better, available witness about Hamil-
ton’s background and social history other than his mother was
uncovered.” Counsel’s failure “to contact persons who might
have had more detailed information about [Hamilton’s] past,”
when the initial investigation put counsel on notice that Ham-
ilton “had a particularly difficult childhood,” renders his per-
formance deficient. Douglas v. Woodford, 316 F.3d 1079,
1088 (9th Cir. 2003).

   [13] There was also available documentary evidence at the
time of trial that could and should have been investigated as
part of the penalty phase investigation. Many of these docu-
ments were in fact in defense counsel’s possession, but he
never reviewed them. The existence of these documents came
to light after the 2003 evidentiary hearing, when Hamilton’s
habeas counsel filed over two hundred pages of newly discov-
ered documents that she had found in a file labeled “Hamilton
Prior Record.” The file contained the following:

    •   March 1967 Kern County Juvenile Court Petition
        (alleges that Hamilton’s home was unfit due to
        abuse and incest)

    •   April 1967 Kern County Juvenile Department
        Report of Probation Officer (describes in detail
        the abuse and incest; recommends that Hamilton
        be declared a dependant child of the court)

    •   April 1967 Kern County Juvenile Department
        Supplemental Report of Probation Officer
        (describes arrests of Hamilton’s father and
        mother for incest and contributing to the delin-
        quency of a minor; notes that Hamilton’s father
        was committed to Atascadero State Hospital and
                 HAMILTON v. AYERS                 13607
    his mother was sentenced to thirty days’ impris-
    onment and three years’ probation)

•   April 1967 Kern County Juvenile Court Hearing
    (adjudges Hamilton a dependant child of the
    court)

•   April 1967 Kern County Juvenile Court Findings
    and Order of Referee (places Hamilton in the
    care of the Kern County Probation Department)

•   May 1967 Kern County Juvenile Court Home
    Placement Order (places Hamilton in Marvin’s
    home)

•   April 1968 Kern County Juvenile Court Home
    Placement Order (places Hamilton in the care of
    the Kern County Welfare Department)

•   May 1968 Kern County Juvenile Court Medical
    Court Order (authorizes the undersigned doctor
    to perform surgery on Hamilton’s fractured clavi-
    cle)

•   January 1969 Kern County Juvenile Court Find-
    ings and Order of Referee (declares Hamilton a
    ward of the court and places him in the care of
    the Kern County Probation Department)

•   February 1969 Kern County Juvenile Court
    Home Placement Order (places Hamilton in the
    home of foster parent Ruby Carter)

•   June 1969 Kern County Juvenile Court Home
    Placement Order (places Hamilton in his moth-
    er’s home but leaves unchanged his status as a
    ward of the court)
13608                     HAMILTON v. AYERS
      •   October 1969 Kern County Juvenile Court Order
          Granting Consent to Marry (grants Hamilton’s
          petition to marry Christine Grealish)

      •   December 1969 Kern County Juvenile Court
          Request and Order for Dismissal of Juvenile
          Court Case (based on Hamilton turning eighteen
          and complying with probation requirements)

      •   1966-1970 Kern County Union High School Dis-
          trict Permanent Record (lists Hamilton’s classes
          and grades at Bakersfield High School and Foot-
          hill High School)

      •   Kern County Criminal Record (includes juvenile
          and adult records for various offenses committed
          by Hamilton, including grand theft, burglary, and
          passing bad checks)

      •   FBI Criminal Record (lists various offenses com-
          mitted by Hamilton between 1970 and 1972,
          including grand theft, deserting the U.S. Army, a
          hold for going AWOL, failure to appear, and bur-
          glary)7

   It is undisputed that Wells obtained these documents prior
to the penalty phase. Intermingled with the other documents
was a two-page investigative report written by Wells on Octo-
ber 8, 1982, two days after the trial began. In the report, Wells
notes that, on October 7, 1982, he went to the Bakersfield
Welfare Department, Juvenile Probation Department, and
Adult Probation Department to search for records, but was
told that Hamilton’s records had been destroyed. He was more
successful at the Kern County Clerk’s Office, where he
  7
    The file also contained a letter dated September 1982, written by Ham-
ilton, in which he recounts his life history. As we briefly explain below,
the authenticity of this letter is disputed.
                          HAMILTON v. AYERS                          13609
obtained a certified copy of Hamilton’s juvenile record. He
also visited Bakersfield High School and Foothill High
School, where he obtained all school records for Hamilton
that had not already been destroyed. Wells’s report is corrobo-
rated by the records themselves, most of which bear a certifi-
cation stamp dated October 7, 1982.8 Yet, some of the records
were not sent to Wells until November 16, 1982,9 two days
before Hamilton was sentenced to death.

   Defense counsel testified at the 2003 evidentiary hearing
that he vaguely recalled asking Wells to obtain Hamilton’s
juvenile dependency records and other relevant documents.
He admitted, however, that he never knew “what the outcome
was of [Wells’s search].” He believed that no records had
been available, yet acknowledged that he had not used the
subpoena power of the court to try to obtain them. In light of
this testimony, the district court’s finding that “counsel did
obtain and review[ ] the records which were available” is
clearly erroneous. Given the limited information about Hamil-
ton’s background that counsel already knew from Marvin’s
interview, he acted deficiently in not reviewing the records
that Wells obtained or attempting to pursue other avenues of
investigation. See Correll, 539 F.3d at 943.

  [14] Counsel also failed to investigate Hamilton’s mental
health history and mental state at the time of trial. See Sum-
merlin, 427 F.3d at 630 (“We have long recognized an attor-
ney’s duty to investigate and present mitigating evidence of
mental impairment. This includes examination of mental
health records.” (citation and internal quotation marks omit-
  8
     The stamp reads: “The document to which this certificate is attached
is a full, true and correct copy of the original on file and of record in my
office.” The stamp is signed by the Deputy County Clerk and Clerk of the
Superior Court of Kern County.
   9
     These records bear a certified stamp dated November 16, 1982. A copy
order form included in the file confirms this date; it is addressed to “Dan
Wells” and notes that ten pages of certified documents are attached.
13610                 HAMILTON v. AYERS
ted)); see also Hendricks, 70 F.3d at 1043 (“Evidence of men-
tal problems may be offered to show mitigating factors in the
penalty phase, even though it is insufficient to establish a
legal defense to conviction in the guilt phase.” (citing Cal.
Penal Code § 190.3(d), (h)). As we discuss below, then avail-
able documentary evidence revealed that Hamilton had suf-
fered from serious mental illnesses throughout most of his
life. Moreover, counsel was aware that Hamilton tried to com-
mit suicide in prison shortly after his wife’s death, and that he
was taking antidepressant medication at the time of trial.

   Defense counsel thus should have retained a mental health
expert and provided the expert with the information needed to
form an accurate profile of Hamilton’s mental health. See
Caro v. Woodford, 280 F.3d 1247, 1254-55 (9th Cir. 2002);
Mayfield, 270 F.3d at 927. We have found ineffective assis-
tance under similar circumstances. See, e.g., Evans v. Lewis,
855 F.2d 631, 636 (9th Cir. 1988) (holding that counsel was
ineffective where he “conducted no investigation to ascertain
the extent of any possible mental impairment” even though
documents available to counsel prior to the sentencing hearing
plainly indicated that the defendant had a history of mental
problems and had even attempted suicide while in prison); see
also Hendricks, 70 F.3d at 1043 (“[W]here counsel is on
notice that his client may be mentally impaired, counsel’s fail-
ure to investigate his client’s mental condition as a mitigating
factor in a penalty phase hearing, without a supporting strate-
gic reason, constitutes deficient performance.“).

  Although the district court did not think it dispositive or
even make a finding on the issue, the State places much reli-
ance on Hamilton’s asserted lack of cooperation. The State
contends that further efforts by defense counsel would have
been unavailing because there is “no indication that Hamilton
would have cooperated” with the investigation. The extent to
which Hamilton refused to assist in the investigation was dis-
puted at the evidentiary hearing. Defense counsel testified that
Hamilton refused to answer questions or provide relevant
                             HAMILTON v. AYERS                          13611
sources of information, which Wells confirmed. Yet, this tes-
timony was undermined by defense counsel’s admission that
he did not even ask Hamilton to complete a basic biographical
information form at the outset of his investigation. In fact,
defense counsel could not recall which specific information
he asked Hamilton to provide. Further, Hamilton testified that
he supplied counsel with an “extraordinary amount of infor-
mation.” He admitted being “antagonistic at times,” but
claimed that, overall, he had been “more than cooperative.”
Counsel also testified that Hamilton insisted on receiving the
death penalty if he were found guilty. The State suggests that
this testimony is corroborated by the statement Hamilton tried
to read to the jury at the outset of the penalty phase.10 Most
fairly read, however, this statement reveals only Hamilton’s
insistence on his innocence and his belief that presenting miti-
gating evidence would be tantamount to admitting guilt.
  10
     The statement that Hamilton wanted to read at trial is similar to a let-
ter he wrote to defense counsel on October 19, 1982, shortly after trial
began. In the letter, which was introduced at the evidentiary hearing, Ham-
ilton states:
       I don’t want to live the rest of my life in prison knowing I was
       there for something I didn’t do. I would rather receive the Death
       Penalty that way on my automatic appeal, some other attorney
       may do what you failed too [sic]; and prove I am not guilty. No,
       if it gets [as] far [as the penalty phase] I won’t have you pleading
       for my life or fabricating any mitigating circumstances to a crime
       I didn’t commit. The only thing I will want is for the press to be
       at the penalty phase to hear a brief statement I will write up for
       you to read to them and the jury.
Hamilton does not dispute that he wrote the letter. He argues, however,
that we should consider it in conjunction with a nine-page letter he alleg-
edly wrote defense counsel on September 20, 1982, in which he recounts
his life history. The district court reopened the evidentiary hearing in Sep-
tember 2004, for the limited purpose of evaluating the authenticity of this
letter. The district court expressed “grave doubts” about whether Hamilton
had in fact written it at the time of trial, but did not make a finding as to
the letter’s authenticity. Given our conclusion that defense counsel was
deficient even assuming Hamilton failed to cooperate, we need not resolve
whether Hamilton wrote the letter at the time of trial or during his habeas
proceedings.
13612                 HAMILTON v. AYERS
   [15] Even if we accept defense counsel’s version of the
events, we would nevertheless find his investigation deficient.
A defendant’s lack of cooperation does not eliminate coun-
sel’s duty to investigate. See 1 ABA Standards for Criminal
Justice 4-4.1 (2d ed. 1980) (“The duty to investigate exists
regardless of the accused’s admissions or statements to the
lawyer of facts constituting guilt or the accused’s stated desire
to plead guilty.”). On the contrary, “if a client forecloses cer-
tain avenues of investigation, it arguably becomes even more
incumbent upon trial counsel to seek out and find alternative
sources of information and evidence, especially in the context
of a capital murder trial.” Silva, 279 F.3d at 847; see, e.g.,
Karis v. Calderon, 283 F.3d 1117, 1136 (9th Cir. 2002)
(determining that the defendant’s lack of cooperation did not
excuse counsel from further investigating mitigating evi-
dence, especially given that “counsel was aware [that the
defendant suffered] childhood abuse and there was essentially
no other significant mitigating evidence to present to the
jury”).

   We recognize that both the Supreme Court and we have
found that a defendant’s refusal to cooperate in the penalty
phase may render counsel’s limited investigation and presen-
tation of mitigating evidence reasonable under the circum-
stances. See, e.g., Schriro v. Landrigan, 550 U.S. 465, 475-77
(2007); Jeffries v. Blodgett, 5 F.3d 1180, 1197-98 (9th Cir.
1993). These cases, however, are readily distinguishable. In
Landrigan, a post-AEDPA case, the defendant actively
obstructed counsel’s investigation and outright refused to
allow counsel to present any mitigating evidence. 550 U.S. at
468-70. For example, the defendant explicitly instructed his
mother and ex-wife not to testify. Id. at 469. Counsel tried to
make a proffer of the witnesses’ testimony, but the defendant
repeatedly interrupted his presentation to the court to reiterate
that he did not want mitigating evidence presented. Id. at 470.
When the judge asked the defendant if he wanted to make a
statement at the conclusion of the penalty phase, he
responded: “I think if you want to give me the death penalty,
                      HAMILTON v. AYERS                   13613
just bring it right on. I’m ready for it.” Id. Similarly, the
defendant in Jeffries refused to allow his counsel to present
any mitigating evidence other than his brother’s brief testi-
mony regarding his artistic abilities. 5 F.3d at 1197. The
defendant made his decision not to present a mitigation
defense “after a weekend of discussions with his brother and
with counsel.” Id. After the defendant explained the various
reasons underlying his decision to the trial court, counsel told
the court he believed that the defendant “made [his decision]
knowingly, voluntarily and intelligently” “after a weekend of
soul searching.” Id.

   [16] By contrast, even if we credit counsel’s testimony
here, at most Hamilton refused to assist in his defense; he did
not impede the many other avenues of mitigating evidence
available to counsel. That counsel somehow learned of five
people to interview and his investigator managed to obtain
over two hundred pages of relevant documents undermines
the State’s argument that Hamilton obstructed the investiga-
tion. Moreover, unlike the defendant in Landrigan, Hamilton
did not threaten to obstruct the presentation of any mitigating
evidence that counsel found. Instead, after the trial court
denied his request to read a statement to the jury, Hamilton
allowed the penalty phase to proceed uninterrupted. Last,
unlike the defendant in Jeffries, he did not make a knowing
and informed decision not to present mitigating evidence. In
any event, because counsel disregarded any alleged instruc-
tions to the contrary and presented a mitigation defense, albeit
an insufficient one, we need not analyze the effect of Hamil-
ton’s alleged refusal to cooperate. See Douglas, 316 F.3d at
1089.
HAMILTON v. AYERS           13615
                    Volume 2 of 2
13616                    HAMILTON v. AYERS
  b)        Penalty Phase Presentation

   [17] Defense counsel compounded the errors he committed
during the investigative stage of the penalty phase by present-
ing almost none of the little mitigating evidence he had dis-
covered. The penalty phase began on November 18, 1982, at
10:00 a.m. By 3:30 p.m. that day, after deliberating for only
four hours, the jury had fixed Hamilton’s sentence as death.
Of the 2423-page trial transcript, the entire penalty phase
spans just 39 pages. Counsel’s anemic presentation resulted
from a number of unjustifiable errors, which, taken together,
render his performance deficient.

   First, counsel waived his opening statement, as he had done
during the guilt phase. He offered no explanation as to why
he forfeited “his first opportunity to explain the significance
of the mitigating evidence to the jury.” Mayfield, 270 F.3d at
928 (internal quotation marks omitted); see Ainsworth, 268
F.3d at 874.

   [18] Second, counsel presented only one witness—
Hamilton’s mother, Jackie—whose testimony occupies less
than 5 pages of the transcript. Although Jackie had firsthand
knowledge of the hardships Hamilton endured during his
childhood, almost none of that information was presented to
the jury, largely due to counsel’s scant questioning. The fol-
lowing exchange is illustrative:

       Q:    All right. Now, Mrs. Piper, a number of years
             ago some problems developed in your home; is
             that correct?

       A:    That is.

       Q:    And at that time was Michael taken from you?

       A:    He was.
                    HAMILTON v. AYERS               13617
Q:   And was that by court? Can you explain that?

A:   It was by court order.

Q:   Okay. And for how long did Michael remain
     outside your home?

A:   I don’t remember exactly.

Q:   Was it more than a year?

A:   Yes, it was.

  ....

Q:   Okay. And did he to your knowledge go from
     foster home to foster home?

A:   Yes, he did.

Q:   Okay. And the reason that he was removed was
     there were problems between you and your hus-
     band; is that correct?

A:   That’s right.

Q:   Okay. And can you indicate to the ladies and
     gentlemen of the jury some of those problems
     regarding his drinking or whatever the problem
     was?

A:   I’d rather not. I don’t believe this has anything
     to do with this at all.

Q:   But there were problems; is that correct?

A:   There are — there were.
13618                 HAMILTON v. AYERS
    Q:   There were problems with abuse?

    A:   Yes.

    Q:   And those are the things that led to Michael’s
         — the removal of Michael from your home?

    A:   Yes.

Counsel asked no further questions about the court order, why
Hamilton moved “from foster home to foster home,” or the
nature of the “problems” with drinking and abuse, although he
was aware—at least to some extent—of this mitigating evi-
dence. Instead, counsel asked questions such as “[Hamilton
and Gwen’s] marriage was good as far as you knew?” Given
that only three days before Hamilton had been found guilty of
murdering his wife by the same jury, this question epitomizes
counsel’s deficient performance.

  Counsel’s subsequent questioning about Hamilton’s father
was similarly lacking:

    Q:   [W]as there ever a relationship [between Hamil-
         ton and his father]?

    A:   Not that I know of.

    Q:   All right. And in part Michael’s father was put
         in prison, was he not, or in a state hospital?

    A:   In a state hospital, yes.

    Q:   Thank you.

Because counsel failed to develop her answers, Jackie’s testi-
mony left the false impression that Hamilton’s childhood,
while unhappy, was not unusual. Indeed, the most detail Jac-
kie offered was a superficial statement that Hamilton was
                      HAMILTON v. AYERS                    13619
kind to “stray animals and stray people” and loved his chil-
dren. Jackie’s reluctance to volunteer information about Ham-
ilton’s childhood is hardly surprising. Given her involvement
in the abuse suffered by Hamilton and his siblings, which we
discuss further below, and the fact that she testified for the
prosecution during the guilt phase, Jackie was one of the
worst witnesses that defense counsel could have presented to
the jury.

   Jackie’s reticence can also be explained by counsel’s fail-
ure to prepare her adequately. Even assuming counsel had
planned to elicit from Jackie the details of Hamilton’s child-
hood background—including the incest and abuse—as he tes-
tified at the evidentiary hearing, the effectiveness of that plan
was severely undercut by not sharing it with Jackie. The
record shows that counsel spent either little or no time prepar-
ing Jackie to testify. Counsel was “pretty sure” he met with
Jackie before putting her on the stand and that she had been
“reluctant” to talk. Counsel recalled Jackie being difficult on
the stand as well, although he conceded that the transcript
undermined his recollection. Jackie, by contrast, stated in a
declaration filed in support of Hamilton’s habeas petition that
she did not recall meeting with Hamilton’s defense counsel or
anyone working on his behalf prior to or during the trial. She
remembered being confused during the penalty phase and not
knowing why defense counsel was asking her questions about
her son’s upbringing. Jackie’s testimony corroborates her rec-
ollection and undermines defense counsel’s. The most telling
example is her response to counsel’s question about the prob-
lems regarding Hamilton’s father’s drinking: “I don’t believe
[that information] has anything to do with this at all.”

   [19] Additional preparation would have made a difference.
Jackie stated in her declaration that she would have testified
in detail about the physical and sexual abuse if she had been
asked to do so. Defense counsel’s assertion that he tried to
elicit this information is not supported by the record. As we
previously have held, the failure to prepare a witness ade-
13620                        HAMILTON v. AYERS
quately can render a penalty phase presentation deficient. See,
e.g., Belmontes, 529 F.3d at 851; Douglas, 316 F.3d at 1087.
This is especially true when the insufficiently prepared wit-
ness is the only penalty phase witness called to testified.

   [20] Counsel exacerbated the damage done during Jackie’s
testimony by not explaining the significance of the meager
mitigating evidence during closing. See Belmontes, 529 F.3d
at 846 n.3 (“Our cases make clear that in addition to present-
ing witnesses to testify about mitigating circumstances,
defense counsel must also explain the significance of the miti-
gating testimony in his closing statement.”). Counsel men-
tioned Jackie’s testimony only once in passing. Moreover,
rather than challenging the prosecutor’s characterization of
Hamilton’s childhood as “unfortunate” but neither unusual
nor extreme,11 he effectively validated it. In addressing
whether any circumstances extenuated the gravity of the
crime, counsel explained: “Michael did come from a broken
home. He was placed in foster home after foster home. I’m
not telling you that’s an excuse, because we know others have
come from homes and have also grown up.” Counsel drasti-
cally understated and mischaracterized Hamilton’s home in
referring to it as merely “broken.” As we explain later, the
environment in which Hamilton grew up was extraordinarily
abusive and atypical in almost every sense. Yet, the jury
remained unaware of this significant mitigating evidence.
Having provided the jury with no reason to show mercy,
defense counsel’s naked pleas to spare Hamilton’s life were
futile. While “[b]egging for mercy is not incompetence per
  11
    During his closing argument, the prosecutor stated:
       Now, I would suspect that counsel will argue that testimony that
       came from his mother Jacqueline Piper that he was taken away
       from his family for a period of time when he was young. And I’m
       not trying to be facetious, that is unfortunate. And that happens
       to so many people in our society. I think anyone sitting here can
       probably think of something bad that’s happened in their child-
       hood. But it’s certainly not any justification for a crime as hei-
       nous as a crime that we have here today.
                      HAMILTON v. AYERS                    13621
se,” Hendricks, 70 F.3d at 1043, this strategy was unreason-
able under the circumstances here.

   The State contends that presenting the mitigating evidence
that it acknowledges was available would have done more
harm than good. There is nothing in the record that supports
this assertion. A decision not to present mitigating evidence
to the jury can be considered tactical only if counsel is aware
of that information and how it could fit into a penalty phase
defense. See Mayfield, 270 F.3d at 927 (“Judicial deference to
counsel is predicated on counsel’s performance of sufficient
investigation and preparation to make reasonably informed,
reasonably sound judgments.”). Defense counsel failed to pur-
sue the relevant information provided to him by the five peo-
ple he and Wells did interview, and did not even review the
records unearthed during Wells’s investigation. The record
belies the State’s assertion that defense counsel “would never
have been able to obtain much of the evidence that Hamilton
has submitted in support of his [habeas] petition . . . no matter
what efforts he made.”

   Moreover, like counsel in Wiggins, defense counsel here
“uncovered no evidence in [his] investigation to suggest that
a mitigation case, in its own right, would have been counter-
productive, or that further investigation would have been
fruitless.” 539 U.S. at 525. The evidence here was not a “bas-
ket of cobras”—there were no “obvious countervailing tacti-
cal dangers for petitioner.” Gerlaugh v. Stewart, 129 F.3d
1027, 1035 (9th Cir. 1997) (internal quotation marks omitted).
For example, contrary to his testimony, counsel had no tacti-
cal reason for not presenting Marvin, Hamilton’s uncle, as a
penalty phase witness. While Marvin did express some nega-
tive opinions about Hamilton during his interview with Wells,
none of them would have done more harm than the failure to
provide the jury with the evidence of the extreme sexual and
physical abuse endured by Hamilton and his siblings. Defense
counsel cited as one reason for not calling Marvin was his
statement that Hamilton cheated on his wife and had been pri-
13622                 HAMILTON v. AYERS
marily interested in the insurance money after her death. Only
a few days before the penalty phase began, however, the jury
had found that Hamilton cold-bloodedly killed his pregnant
wife for financial gain. Thus, the potential damage that Mar-
vin’s testimony might have caused had already been inflicted.
Marvin’s belief that Hamilton did not pay attention to his chil-
dren was also relatively innocuous, since the jury had already
heard testimony that Hamilton initially planned to kill Gwen
in front of his four children. In any event, limiting the scope
of a penalty phase presentation to evidence that the defendant
is a good person who has done good deeds is, in and of itself,
unreasonable where there is an extreme unlikelihood that any
testimony about the defendant’s character would be sufficient
to humanize him. Correll, 539 F.3d at 945-46. Marvin could
have testified about the countless difficulties Hamilton
endured as a child, which would have removed Hamilton
from the category of those who have experienced “unfortu-
nate” circumstances and placed him squarely in the realm of
“unusual or extreme” childhood suffering. Instead, the jury
heard only Jackie’s vague and terse testimony, which can
hardly be considered a mitigation defense, much less a strate-
gically reasonable one.

   Nor did counsel offer a legitimate reason for not trying to
elicit the details of Hamilton’s background from his sister
Vicki. See id. at 948 (“A decision by counsel not to present
mitigating evidence cannot be excused as a strategic decision
unless it is supported by reasonable investigations.”); cf. Wil-
liams v. Woodford, 384 F.3d 567, 616-624 (9th Cir. 2004)
(listing four legitimate reasons that supported counsel’s tacti-
cal decision not to present certain penalty phase evidence). On
the contrary, counsel admitted that he never considered pre-
senting Vicki as a penalty phase witness, even though she
could have painted a portrait of Hamilton’s childhood that
would have greatly aided the jury as she had direct knowledge
of the extensive abuse endured by Hamilton and his siblings.

  [21] Counsel also acted deficiently in not contacting Hamil-
ton’s other sister, Carolyn, who could have provided the most
                             HAMILTON v. AYERS                        13623
poignant and revealing mitigating evidence, as her declaration
demonstrates. The district court clearly erred in finding that
counsel could not talk to Carolyn because she was an “ad-
verse part[y] represented by counsel,” which was the reason
defense counsel gave for not interviewing her. Carolyn was
not an adverse party; she was Hamilton’s codefendant. More-
over, defense counsel could have subpoenaed Carolyn to
interview her about Hamilton’s background. The district
court’s conclusion that counsel made a reasonable tactical
decision to present only one witness is therefore clearly erro-
neous.

  c)        Available Mitigating Evidence

   [22] Counsel would have learned extensive information
about Hamilton’s background if he had conducted a reason-
ably thorough investigation. Various family members, physi-
cians, and others could have testified about the abusive
environment in which Hamilton grew up and his ongoing
mental health problems.12 This information could have been
  12
   Hamilton presented the declarations of the following twenty-seven
people at the 2003 evidentiary hearing:
       •   Jackie Piper (Hamilton’s mother)
       •   Carolyn Hamilton (Hamilton’s sister)
       •   Vicki Fitzherbert (Hamilton’s sister)
       •   Christine Woods [née Grealish] (Hamilton’s ex-wife)
       •   Donna Borgerding (Hamilton’s maternal aunt)
       •   Patricia Johnson (Hamilton’s maternal aunt)
       •   Carol Hamilton (Hamilton’s paternal aunt; Marvin’s wife)
       •   Elaine Honor (Hamilton’s paternal aunt)
       •   Jack Hamilton (Hamilton’s paternal uncle)
       •   Sandi Clark (Hamilton’s cousin)
       •   Janel Daniels (Hamilton’s cousin)
       •   Kristine Daniels (Hamilton’s cousin)
13624                        HAMILTON v. AYERS
corroborated and supplemented by available records.13

       •   Patricia Ketchum Ortega (Carolyn’s foster sister and Gilbert
           Garay’s girlfriend at the time of the crime)
       •   Lillian Cagle (ex-wife of Hamilton’s father, Bob)
       •   Marian Anderson (ex-wife of Hamilton’s cousin, Roy Hamil-
           ton)
       •   Patricia Hamilton (second wife of Roy Hamilton)
       •   Bill Underwood (son of Ernest and Nellie Underwood, Hamil-
           ton’s foster parents)
       •   Nina Huff (neighbor of the Underwoods)
       •   James Beasely (nephew of Ruby and Oliver Cater, Hamilton’s
           foster parents)
       •   Floyd Daniel (Hamilton’s former employer)
       •   Lawrence McInerney (Hamilton’s former employer)
       •   Mosetta Mangrum (Hamilton’s former landlady)
       •   William Karwacki (retired school psychologist; evaluated
           Hamilton in 1964 at the request of his teacher)
       •   Dr. James W. Wilkins (retired clinical psychologist; evaluated
           Hamilton in 1965)
       •   Dr. James R. Merikangas (psychiatrist and neurologist; evalu-
           ated Hamilton in 1992)
       •   Shirley A. Reece, M.S.W. (clinical social worker; evaluated
           Hamilton in 1993)
     • Dr. George Woods (psychiatrist; evaluated Hamilton in 1994).
  13
    In addition to the “Prior Record” materials that counsel failed to
review at the time of trial, Hamilton presented almost two hundred pages
of other readily available documents that counsel never discovered. These
documents include numerous psychological evaluations of Hamilton and
recommendations for treatment, starting at the age of twelve; Bob’s U.S.
Air Force record (includes a discharge request due to Jackie’s and Hamil-
ton’s “mental problems”; notes that Bob attempted suicide); Bob’s crimi-
nal record for the incest offense (includes the complaint, arrest warrant,
transcripts of proceedings, guilty-plea conviction, commitment to Atas-
cadero State Hospital, and probation report); Atascadero State Hospital
records (note Bob’s diagnosis as a mentally disordered sex offender); Jac-
kie’s criminal record for contributing to the delinquency of a minor
(includes the complaint, transcripts of proceedings, psychological evalua-
tions, conviction, sentence, and probation report).
                       HAMILTON v. AYERS                   13625
Because of counsel’s deficient performance, however, the
jury heard almost none of the following mitigating evidence.

    i.   Family Background and Social History

   For most of his childhood, Hamilton lived with his father,
Bob, his mother, Jackie, and his younger sisters, Carolyn and
Vicki. The family moved eleven times over a fourteen-year
period due to Bob’s service in the U.S. Air Force. Bob began
drinking heavily when Hamilton was only six months old. As
his drinking worsened, Bob became an increasingly “mean
and vicious” man. He physically abused Jackie throughout
their marriage. He also attempted to control her and the chil-
dren at all times. He killed any pets to which the children
grew attached. He also frequently terrorized the children by
forcing them to watch as he battered and degraded their
mother, often threatening to kill her. If the children attempted
to flee, Bob would drag them back by their limbs or hair. At
times, he and Jackie wielded butcher knives at one another
while the children watched. They both regularly beat Hamil-
ton using either a paddle, switch, belt, or closed fists, but oth-
erwise ignored him.

   Hamilton’s parents engaged in inappropriate sexual behav-
ior as well. Both parents walked around the home naked, fon-
dling each other and making lewd comments in front of their
children. On at least two occasions, Bob ritualistically lined
up Hamilton and his sisters and made them watch as he forced
Jackie to copulate him orally. Bob also sexually abused Caro-
lyn for approximately four years. The abuse, which began
when Carolyn was only ten years old, happened two to three
times per week and included sexual intercourse and oral copu-
lation. All of this occurred with the full knowledge of Hamil-
ton’s mother. Rather than protecting Carolyn from the abuse,
she at times guarded the door to prevent Hamilton and Vicki
from disturbing Bob and Carolyn in the bedroom. Jackie was
also frequently present in the bed with her husband and
daughter. On several occasions, Jackie pinned Carolyn to the
13626                     HAMILTON v. AYERS
bed and covered her mouth so that Hamilton and Vicki would
not hear her crying. Other times, Jackie participated in a
“three-way deal” with her husband and Carolyn; Jackie would
engage in mutual foreplay and intercourse with Bob before he
penetrated Carolyn. Jackie also bought contraceptive jelly for
her. Hamilton was aware of his father’s sexual abuse and of
his mother’s acquiescence in it. He tried to defend his sister,
but his father beat him and threatened to kill him.

   The sexual abuse extended beyond Hamilton’s immediate
family. Bob’s father had sexually abused both of Bob’s sis-
ters, and had tried to molest Carolyn. Two of Bob’s brothers,
Marvin and Don, sexually abused their daughters as well.
Unbeknownst to Hamilton at the time, Marvin also sexually
abused Carolyn. That abuse began after Bob’s abuse was dis-
covered, and continued sporadically for seven years until Car-
olyn was twenty-one.

   Carolyn told Marvin and her aunt Karen about her father’s
abuse in March 1967, when she was fourteen and Hamilton
was fifteen. Marvin and Karen in turn reported the abuse to
the police. Bob was arrested immediately, and Jackie was
arrested three days later. Hamilton and his siblings were then
taken into protective custody. In a dependency petition filed
in the Kern County Juvenile Court the following day (one of
the documents in defense counsel’s possession at the time of
trial),14 a probation officer described Hamilton’s home as “an
unfit place for him by reason of neglect, cruelty, or depravity”
and “detrimental to said minor’s moral upbringing in that said
minor was present in the family home when incestuous acts
occurred between said minor’s sister, Carolyn Hamilton, and
her father; further, said minor’s mother, who had knowledge
of the above mentioned incestuous activity, did nothing to
  14
     As already discussed, most of the Kern County Juvenile Court records
pertaining to Hamilton’s removal from his parents’ home and his subse-
quent placement in foster care were in counsel’s possession at the time of
trial, but he never reviewed them.
                      HAMILTON v. AYERS                  13627
inhibit these acts.” A ten-page report filed by another proba-
tion officer approximately two weeks later contains additional
detail about the sexual abuse and family history. The report
also includes statements by Hamilton, Carolyn, and Jackie.
The Kern County Juvenile Court adopted the report’s recom-
mendation and declared Hamilton a dependent of the court
and placed him temporarily in shelter care.

   Approximately a month after his arrest, Bob pled guilty to
the charge of “willfully, unlawfully, feloniously, knowingly
and incestuously hav[ing] sexual intercourse with [his daugh-
ter] Carolyn Marie Hamilton, of the age of fourteen years
old.” After several psychiatric evaluations, Bob was adjudged
a mentally disordered sex offender and committed to Atas-
cadero State Hospital. He was released less than a year later
and sentenced to five years’ probation. He was also required
to register as a sex offender and to avoid any contact with his
wife and children.

   Jackie was charged with a misdemeanor violation of con-
tributing to the delinquency of a minor. She also underwent
psychiatric evaluation. One examiner noted that Jackie dem-
onstrated “no great remorse” for her role in the abuse. The
court ultimately determined that Jackie was not a mentally
disordered sex offender. She was sentenced to thirty days’
imprisonment and three years’ probation. She was later sen-
tenced to another year in prison for violating her condition of
probation that she not see her children without court permis-
sion.

   Hamilton spent the next few years moving from one foster
home to another. In May 1967, shortly after his parents’
arrests, he was placed with his uncle Marvin, with whom he
had a “friendly relationship.” This relationship ended after a
few months, however, when Carolyn moved in and Hamilton
witnessed his uncle molesting her. Marvin was convicted of
grand theft shortly thereafter, and Hamilton and his sister
returned to shelter care. Hamilton was then placed with the
13628                 HAMILTON v. AYERS
Rogers, with whom he had difficulty adjusting. His placement
was terminated after a few months for unspecified reasons.

   In January 1968, at the age of sixteen, Hamilton was placed
in the foster home of Ernest and Nellie Underwood. In his
declaration, the Underwoods’ son, Bill, stated that Hamilton
“had two sides to his personality. One side was a quiet, help-
ful, shy, obedient, and introverted child. The other was an irri-
table and agitated individual who did things on impulse. Most
of these dark periods came after [Hamilton] had either per-
sonal or telephone contact with family members.” Bill also
noted that Hamilton “was a loner who had no close friends
and few if any acquaintances.” In December 1968, Hamilton
was sent to juvenile hall on two separate occasions for using
the Underwoods’ truck and for attending his high school
prom, both without their permission. On January 10, 1969, the
Kern County Juvenile Court adjudged Hamilton a ward of the
court. Hamilton remained in juvenile hall until February 7,
1969, when he was placed in his third foster home. The home
was run by Ruby and Oliver Carter, who were known for
physical punishment. According to their nephew, James
Beasely, Hamilton was beaten by Ruby with a belt. Hamilton
requested that his case worker remove him from their home.
His placement with the Carters was terminated after only four
months. Hamilton returned to his mother’s home in June
1969.

   As he had complied with the terms of his probation, Hamil-
ton’s wardship was dismissed on December 19, 1969, shortly
after he married Christine Grealish. On April 23, 1970, their
son was born. Hamilton’s union with Christine was short-
lived, however; they separated after a year and divorced in
July 1973. During their marriage, Hamilton had a difficult
time retaining a job and committed a number of relatively
minor crimes. In April 1974, Hamilton married Gwen, whom
he had been dating since his divorce. Between 1975 and 1980,
he and Gwen had four children together. His employment and
legal troubles continued during their marriage.
                          HAMILTON v. AYERS                         13629
       ii.   Mental Health History

   Even a cursory investigation would have revealed that
Hamilton has suffered from serious mental health problems
throughout most of his life. The problems were first discov-
ered when Hamilton was twelve years old, around the time he
became aware of his father’s sexual abuse of Carolyn. In Feb-
ruary 1964, William Karwacki, then a school psychologist,
conducted a clinical examination of Hamilton at the request
of one of his middle school teachers. Karwacki noted that his
1964 report observed that Hamilton’s feelings of “resentment
and isolation” have caused him to react negatively and antiso-
cially in some instances, and violently and destructively in oth-
ers.15 Karwacki also noted Hamilton’s feeling that “his life
and efforts have generally ended in failure.” Hamilton
appeared “well trained to offer a positive account of his home
environment to outsiders, and although acknowledging fre-
quent physical punishment, he hastened to add that he always
‘had it coming.’ ” After evaluating Hamilton, Karwacki con-
cluded that Hamilton was “in critical need of immediate ther-
apeutic intervention, through treatment by either a child
psychiatrist or a psychiatric social worker.” Karwacki
attempted to conference with Hamilton’s parents, but they
were evasive and “expressed ignorance of any reasons for
[Hamilton’s] psychological distress.”

   Approximately a year later, Hamilton took a personality
test used to assess mental, emotional, and psychological
pathology, which was administered by the Juvenile Court for
the Grant County Superior Court in Ephrata, Washington,
where Hamilton’s family lived at the time. James Wilkins, a
clinical psychologist, examined the results of that test. Wil-
  15
     Hamilton submitted Karwacki’s 1964 report at the evidentiary hearing
held by the district court, along with a declaration prepared by Karwacki
in July 1994 at the request of Hamilton’s habeas counsel. Karwacki notes
in his declaration that he was available and willing to testify at the time
of trial but was never contacted by anyone working on Hamilton’s behalf.
13630                      HAMILTON v. AYERS
kins diagnosed Hamilton as suffering from schizophrenic
paranoid disturbances and feelings of depression and hope-
lessness. In a letter written to the Juvenile Probation Officer,16
Wilkins noted that Hamilton’s results demonstrated “unpre-
dictability in behavior and attitude” and “[i]nner conflicts
regarding sexual matters . . . [that] relate to feelings generated
within the family.” Based on his psychological assessment,
Wilkins determined that Hamilton was “in immediate need of
intensive psychological and/or psychiatric evaluation and
treatment.” The Juvenile Probation Officer agreed with Wil-
kins’s recommendation and informed the Juvenile Department
that Hamilton “is in definite need of either professional psy-
chological help and [sic] possibly psychiatric care.”

  Hamilton’s parents were aware of his mental health prob-
lems. In April 1967, Bob and Jackie requested that the Grant
County Juvenile Department provide “professional help” for
Hamilton due to his “adjustment problems.” The following
month, Bob requested a discharge from the Air Force on the
ground that both his wife and son were suffering from mental
health problems. In his request letter, Bob states that Hamil-
ton “has a mental problem . . . [and] needs special schooling
and psychiatric care.” Although Bob’s discharge request was
granted, Hamilton never received any treatment.

  By age eighteen, Hamilton’s condition had worsened.
According to Shirley Reece, a clinical social worker who
evaluated him in 1994,17 Hamilton recalled feeling hopeless
and despondent about his life at the time. Hamilton’s mental
   16
      This letter, dated May 10, 1965, was submitted at the evidentiary hear-
ing, as was a declaration prepared by Wilkins in July 1994. Wilkins was
also available and willing to testify at the time of trial but was never con-
tacted by anyone working on Hamilton’s behalf.
   17
      Reece prepared a thirty-two page declaration, which was submitted at
the district court’s evidentiary hearing, detailing Hamilton’s social history
and family background. To reach her conclusions, she interviewed Hamil-
ton, Carolyn, Jackie, and one of Hamilton’s aunts, and reviewed over 1200
pages of relevant documents.
                       HAMILTON v. AYERS                   13631
health further deteriorated after he joined the Army at nine-
teen. Shortly after enlisting, he went AWOL and attempted
suicide by slashing his wrists with a pen knife. Hamilton’s
then-wife Christine recalled Hamilton being severely
depressed. Between January 1971 and July 1972, Hamilton
went AWOL five more times. During one of his absences, he
shot himself in the leg and refused hospital attention for fear
of being arrested.

  Mental health problems, like sexual abuse, were rampant in
Hamilton’s immediate and extended family as well. Prior to
being discharged, Bob had threatened to commit suicide on
several occasions. A clinical report prepared by Army medi-
cal examiners notes that, on one occasion in July 1964, Bob
“made out a will in a local tavern, handed it to the tavern
owner and stated he was going to commit suicide.” In April
1965, Bob discharged a shotgun in his home while Hamilton
and his siblings were there. Although Bob later said to the
Army officials that it was an accident, he had initially told
Jackie that it was a suicide attempt. He confirmed his state-
ment to Jackie at the time of his arrest for incest. Carolyn later
reported that Bob tried to kill himself on at least one other
occasion when he was home alone with her.

   Jackie also experienced mental health problems. In October
1965, she voluntarily admitted herself to the Agnews Devel-
opmental Center in San Jose. According to her record of
admission, which Hamilton submitted at the evidentiary hear-
ing, Jackie complained of experiencing depression for several
months. She cried frequently and reportedly threatened “to
harm her husband and children.” Jackie was discharged with
a diagnosis of “Psychoneurotic Reaction” and “Depressive
Reaction.” Although further treatment was recommended,
there is no record of any follow-up.

  Members of Hamilton’s extended family suffered from
depression and suicidal thoughts as well. His paternal great-
grandmother spent time in a mental institution and later com-
13632                 HAMILTON v. AYERS
mitted suicide. More recently, his cousin Roy, the son of
Bob’s brother Don, committed suicide in 1989. Roy’s sister,
Sandi, stated in her declaration that Roy was antisocial,
moody, and paranoid in the years before his death.

    iii.   Mental Health at the Time of Trial

   Hamilton’s mental health showed no signs of improvement
two decades after his initial psychiatric evaluations. Rather,
the available documentary evidence reveals he was still suf-
fering from depression at the time of trial. Hamilton testified
that he had attempted suicide in prison in December 1981,
shortly after his wife’s death, by injecting toilet bowl cleaner
into his arm. Defense counsel was aware of the incident
before trial began but disputed that it was a legitimate suicide
attempt. Hamilton allegedly told counsel that he faked the
attempt so he could sleep in a better bed, eat a good meal, and
try to escape. Hamilton unequivocally denied making this
statement.

   Approximately five months after the alleged attempt, Ham-
ilton was treated for depression while awaiting trial. The
attending psychologist diagnosed him as having “[a]djustment
disorder, with depressed mood subsequent to being incarcer-
ated and charged with murder.” A physician thereafter pre-
scribed an antidepressant medication, Tofranil. On October
18, 1982, one month before the penalty phase, Hamilton
wrote defense counsel a note telling him that he was taking
Tofranil. Hamilton provided a telephone number followed by
the words, “Mental Health”; beneath the number, Hamilton
wrote, “Ask to speak to someone concerning my medication.”
Counsel testified at the evidentiary hearing that he never
investigated the specific effects of Tofranil. It is undisputed
that defense counsel was not a physician or otherwise quali-
fied to evaluate Hamilton’s mental health at the time of trial.

  When Hamilton was reevaluated for purposes of his habeas
petition by Shirley Reece, George Woods (a psychiatrist), and
                         HAMILTON v. AYERS                       13633
James Merikangas (a psychiatrist and neurologist),18 they all
agreed that his abusive childhood had adversely impacted his
mental health and that the negative effects had worsened over
time. These effects were explained in the declarations that
these doctors submitted at the evidentiary hearing. Reece
summarizes her evaluation of Hamilton as follows:

       To know and understand Michael Hamilton, one
       must consult many first hand sources, most impor-
       tant of which are the family into which he was born.
       By all current measures, he was raised in an environ-
       ment of intergenerational alcoholism, child abuse,
       and domestic violence . . . . [Y]et, tragically no indi-
       vidual, agency, nor military authorities ever inter-
       vened to protect the children . . . . . There is
       abundant evidence that all of the children in the
       Hamilton family were severely deprived in every
       sense of the word and lacked the normal affectional
       bonds and guidance which foster healthy develop-
       ment and prosocial behavior . . . . Michael was
       repeatedly subjected to gross maltreatment and
       incredible psychological abuse; and surely by all rea-
       sonable standards his parents’ behavior was both
       deviant and depraved.

   Woods’s declaration corroborates Reece’s assessment of
Hamilton’s background and supplements it with medical
opinions. Woods observes that Hamilton’s “sense of hopeless-
ness, learned helplessness and chronic anxiety have their roots
in those times he was forced to witness sadistic attacks against
family members and was unable to help them.” Woods con-
cludes that, throughout his life, Hamilton has endured “envi-
ronmental, developmental and traumagenic factors beyond his
  18
    Like Reece, Woods both interviewed Hamilton and reviewed over one
thousand pages of relevant documents as part of his evaluation. Although
Merikangas did not interview Hamilton, he did review all the available
medical records and other relevant documents.
13634                 HAMILTON v. AYERS
control,” which have resulted in “serious psychiatric disorders
that substantially altered his ability to understand and function
in the world around him.” Woods determines that these disor-
ders “compromise [Hamilton’s] ability fully to appreciate the
nature and consequences of his acts or to conform his conduct
to the requirement of law.” Woods adds that the medication
Hamilton was taking during trial “exacerbated preexisting
mental disorders and made it extremely unlikely that he
would have been able to weigh and consider such issues as
the advantages and disadvantages to testifying.” Merikangas’s
review of the relevant records similarly led him to conclude
that “Hamilton in all likelihood has significant neurological
dysfunction and psychiatric impairments that affected his
behavior both at the time of the offense and subsequently.”
The State offered no testimony or declarations to rebut the
conclusions of Reece, Woods, and Merikangas.

   [23] “We realize that the duty to investigate and prepare a
defense is not limitless,” and that “it does not necessarily
require that every conceivable witness be interviewed or that
counsel must pursue every path until it bears fruit or until all
conceivable hope withers.” United States v. Tucker, 716 F.2d
576, 584 (9th Cir. 1983) (quoting Lovett v. Florida, 627 F.2d
706, 708 (5th Cir. 1980)) (internal quotation marks omitted).
We impose nowhere near that standard of perfection here.
Defense counsel did not even exhaust the few sources of
information of which he was aware. Rather, he effectively
abandoned his investigation “after having acquired only rudi-
mentary knowledge of [the defendant’s] history from a nar-
row set of sources.” Wiggins, 539 U.S. at 524. Given the
abundance of classic mitigating evidence that was available,
we conclude that counsel’s investigation fell far below the
constitutional floor.

  d)    1982 Standard

   [24] In reaching its conclusion that defense counsel’s per-
formance was not deficient, the district court went astray by
                      HAMILTON v. AYERS                    13635
holding counsel to a lesser standard of performance than
existed in 1982. As the Supreme Court has long recognized,
the ABA Standards for Criminal Justice provide guidance as
to what constitutes a “reasonable” performance. Strickland,
466 U.S. at 688-89; see Rompilla v. Beard, 545 U.S. 374, 387
(2005); Wiggins, 539 U.S. at 524; Williams, 529 U.S. at 396.
The standards in effect at the time of Hamilton’s trial recog-
nized that “[i]t is the duty of the lawyer to conduct a prompt
investigation of the circumstances of the case and to explore
all avenues leading to facts relevant to the merits of the case
and the penalty in the event of conviction.” 1 ABA Standards
for Criminal Justice 4-4.1 (2d ed. 1980) (emphasis added).
Fulfilling these obligations was as crucial in 1982 as it is
today “in order to assure individualized sentencing and the
defendant’s right to a fair and reliable capital penalty proceed-
ing.” Ainsworth, 268 F.3d at 877. We thus have held that trial
counsel falls below these standards by failing to investigate
adequately and present available mitigating evidence to the
jury. See, e.g., Summerlin, 427 F.3d at 629-33 (1982 trial)
(holding that counsel performed deficiently where he failed to
investigate and present available mitigating evidence that the
defendant was severely abused as a child and had suffered
from ongoing mental health problems); see also, e.g., Karis,
283 F.3d at 1139 (1982 trial) (holding that counsel’s perfor-
mance was not reasonable under the circumstances where he
was aware of evidence that the defendant was severely beaten
as a child and yet failed to investigate the evidence further or
to present it to the jury); Silva, 279 F.3d at 847 (1982 trial)
(holding that counsel was deficient in failing to meet his “duty
to determine what evidence was out there in mitigation in
order to make an informed decision as to how to best repre-
sent his client”); Ainsworth, 268 F.3d at 877 (1980 trial)
(“[C]ounsel’s deficient performance resulted from the failure
to prepare and present mitigating evidence, interview wit-
nesses, and investigate available documents and other avail-
able information.”).

   The district court made much of the fact that the
“[s]tandard practice in death penalty defense in Tulare County
13636                 HAMILTON v. AYERS
in 1982, the time of Hamilton’s trial, was different from
today[’s].” In focusing on the particular ways in which the
“standard practice” has changed, however, the district court
failed to recognize the ways it has remained the same. For
example, we need not decide whether standard practice at the
time of trial included retaining a “mitigation expert”—
someone specially trained in investigating and presenting mit-
igating evidence at the penalty phase of a capital trial—
because the deficient performance here did not result from
counsel’s failure to hire a specialized investigator. Rather, it
resulted from counsel’s failure to pursue obvious leads pro-
vided by the people he did interview, to review relevant docu-
ments that were in his possession, and to present to the jury
the mitigating evidence of which he was aware, among the
other errors we have chronicled above. Similarly, we need not
decide whether standard capital practice in Tulare County in
1982 included preparing a “social history” report per se. It is
undisputed that counsel was required to obtain the type of
available information that a social history report would con-
tain, such as family and social background and mental health,
which Hamilton’s counsel failed to do.

   [25] The district court clearly erred in relying on the testi-
mony of Hamilton’s trial counsel as to the “standard capital
practice” at the time of trial and rejecting the testimony of
Hamilton’s Strickland expert. Trial counsel had never before
worked on a death penalty case, had never attended a death
penalty seminar, and did not recall looking into the ABA stan-
dards before or during his representation of Hamilton. By
contrast, the Strickland expert’s testimony as to the minimal
steps that counsel was required to take in 1982 is consistent
with our established case law and that of the Supreme Court.
The district court’s finding that defense counsel satisfied these
minimal obligations is clearly erroneous. The jury “saw only
glimmers of the defendant’s history, and received no evidence
about its significance vis-a-vis mitigating circumstances.”
Ainsworth, 268 F.3d at 874 (alterations and internal quotation
marks omitted). Moreover, as in Ainsworth, “[a] reasonable
                      HAMILTON v. AYERS                   13637
investigation would have uncovered a substantial amount of
readily available mitigating evidence that could have been
presented to the jury.” Id. Because both the investigation and
presentation of mitigating evidence at the penalty phase were
unreasonable under the prevailing professional norms at the
time of trial, we hold that counsel’s performance was defi-
cient.

  2.   Prejudice

   Deficiency and prejudice questions, although distinct, are
closely related. Correll, 539 F.3d at 951. To establish preju-
dice, Hamilton “must show that there is a reasonable probabil-
ity that, but for counsel’s unprofessional errors, the result of
the proceeding would have been different. A reasonable prob-
ability is a probability sufficient to undermine confidence in
the outcome.” Strickland, 466 U.S. at 694; see Belmontes, 529
F.3d at 863 (clarifying that the reasonable probability stan-
dard is “less than the preponderance more-likely-than-not
standard” (internal quotation marks omitted)). Accordingly,
“[i]n establishing prejudice under Strickland, it is not neces-
sary for the habeas petitioner to demonstrate that the newly
presented mitigation evidence would necessarily overcome
the aggravating circumstances.” Correll, 539 F.3d at 951-52
(citing Williams, 529 U.S. at 398); see Rompilla, 545 U.S. at
393 (“[A]lthough we suppose it is possible that the jury could
have heard . . . all [the mitigating evidence] and still decided
on the death penalty, that is not the test.”).

   Instead, in assessing prejudice, we must “compare the evi-
dence that actually was presented to the jury with the evi-
dence that might have been presented had counsel acted
differently,” Bonin v. Calderon, 59 F.3d 815, 834 (9th Cir.
1995), and “evaluate whether the difference between what
was presented and what could have been presented is suffi-
cient to ‘undermine confidence in the outcome’ of the pro-
ceedings,” Lambright, 490 F.3d at 1121 (quoting Strickland,
466 U.S. at 694). This requires us to “evaluate the totality of
13638                  HAMILTON v. AYERS
the available mitigation evidence—both that adduced at trial,
and the evidence adduced in the habeas proceeding” and “re-
weigh[ ] it against the evidence in aggravation.” Williams,
529 U.S. at 397-98. “Prejudice is established if ‘there is a rea-
sonable probability that at least one juror would have struck
a different balance’ between life and death.” Belmontes, 529
F.3d at 863 (quoting Wiggins, 539 U.S. at 537).

   [26] Defense counsel failed to investigate and present a
substantial amount of classic mitigating evidence. The portrait
painted at the evidentiary hearing before the district court
“was far different from the unfocused snapshot handed the
superior court jury.” Bean v. Calderon, 163 F.3d 1073, 1081
(9th Cir. 1998). The jury that recommended the penalty of
death heard only that Hamilton had been placed temporarily
in foster care due to unspecified problems at home, that he
was kind to stray animals and stray people, and that he loved
his children. It had no knowledge of the indisputably horrific
treatment Hamilton and his siblings suffered at the hands of
his mother, father, and various extended family members. It
did not hear that Hamilton had been diagnosed with mental
health problems as early as age twelve, and that he had ongo-
ing depression and suicidal thoughts through trial.

   Both the Supreme Court and we have found the failure to
investigate and present similar—and even less compelling—
evidence to be highly prejudicial. See, e.g., Rompilla, 545
U.S. at 390-93 (failure to discover and present evidence that
defendant was raised in a slum; was beaten by his parents;
witnessed his father’s frequent abuse of his mother; quit
school at sixteen; had no indoor plumbing; and may have had
schizophrenia or another mental disorder); Williams, 529 U.S.
at 369, 370 (failure to investigate and present evidence that
defendant had been abused and neglected during his child-
hood, and that he was “ ‘borderline mentally retarded,’ had
suffered repeated head injuries, and might have mental
impairments organic in origin”); Belmontes, 529 F.3d at
861-63 (counsel ignored tantalizing leads indicating that
                      HAMILTON v. AYERS                  13639
defendant had suffered rheumatic fever and other illnesses as
a child; suffered depression after the death of his sister; had
an antisocial personality disorder; had a history of substance
abuse; and had struggled academically until he dropped out of
school); Douglas, 316 F.3d at 1088 (counsel failed to discover
and present evidence that defendant was abandoned as a child
and raised by foster parents, including an abusive alcoholic
foster father who frequently locked him in a closet; rarely had
enough food; and was beaten and raped in jail at the age of
fifteen); Karis, 283 F.3d at 1139 (failure to present any evi-
dence of the substantial abuse suffered by defendant; avail-
able records showed that defendant’s father and stepfather
“viciously beat” him and his mother on a regular basis).

   The district court clearly erred in relying on the State’s
argument that the mitigating evidence could not have made a
difference in the outcome of the penalty phase because the
crime Hamilton committed was not “attributable to” his disad-
vantaged background or mental health problems. As a matter
of law, the trial court could not have excluded the mitigating
evidence on this ground. Doing so would have directly vio-
lated the Supreme Court’s longstanding instruction that “a
State cannot preclude the sentencer from considering any rele-
vant mitigating evidence that the defendant proffers in support
of a sentence less than death,” as “virtually no limits are
placed on the relevant mitigating evidence a capital defendant
may introduce concerning his own circumstances.” Payne v.
Tennessee, 501 U.S. 808, 822 (1991) (internal quotation
marks omitted); see Tennard v. Dretke, 542 U.S. 274, 285-88
(2004) (holding that evidence of impaired mental functioning
is inherently mitigating, and that a defendant need not demon-
strate a “nexus” between his mental capacity and the crime
committed).

  Counsel’s failure to retain an expert to explain the mitigat-
ing value of Hamilton’s traumatic childhood was all the more
prejudicial because obtaining the evidence and calling an
expert to explain its relationship to Hamilton’s murder of his
13640                 HAMILTON v. AYERS
wife—as opposed to a random act of violence aimed at soci-
ety in general—could very well have altered the outcome. See
Belmontes, 529 F.3d at 869 (“A lay juror is not trained to
identify the specific psychological and behavioral conse-
quences of the traumas that [the defendant] experienced . . . .
Accordingly, expert testimony should have been presented
with respect to these issues.”); see also Richter v. Hickman,
No. 06-15614, 2009 WL 2425390, at *15 (9th Cir. Aug. 10,
2009) (holding that the “primary source of prejudice lay . . .
in counsel’s failure to consult, and subsequently to call, an
expert in blood spatter,” where the blood spatter testimony
was “the linchpin of the defense”). For example, Reece
declares that Hamilton “is both a product and a victim of a
very unstable and abusive home environment, characterized
by [his] father’s alcoholism, ongoing domestic violence, and
the shared family ‘secret’ of the father’s incestuous relation-
ship with his oldest daughter.” She adds that “several major
studies (following subjects for more than 20 years) confirm
the strongly negative impact of such environmental influ-
ences.” Wilkins concludes that the “severity of the life-
threatening violence, parental combat, and personal physical
abuse to which [Hamilton] was exposed, was of the type rec-
ognized by clinicians as capable of producing thought distur-
bances, delusional thinking and dissociative behavior as
defenses to immediate psychological trauma.” Merikangas
similarly observes that

    [v]ictimization as a child has catastrophic and per-
    manent effects on those who, like [Hamilton], sur-
    vive it. It has a severe impact on the child’s mental
    development and maturation. Sustained feelings of
    terror, panic, confusion, and abandonment as a child
    have long term consequences for adult behavior.
    Psychosis, dissociative states, depression, disturbed
    thinking and alcohol and drug dependency are
    directly related to child victimization.
                      HAMILTON v. AYERS                    13641
He also notes that “[p]hysical and emotional childhood
trauma is especially devastating when the injuries are inflicted
by those whom the child must rely on for protection.”

  While Woods agrees with the others experts’ conclusions,
he adds a different perspective as well:

    Michael responded to his father’s abusive accesses
    and pathology by developing counter phobic reac-
    tions. Early on in his life, he vowed that he would
    not repeat the actions of his father or mother . . . . He
    overcame multigenerations of alcohol and drug
    abuse and did not drink alcoholic beverages or use
    drugs . . . . He resisted urges to fight or strike back,
    even when attacked by peers at school or his father
    at home, and was resolute in his desire to not
    become violent. He consciously devoted himself to
    not duplicating the behavior of his father.

The prosecutor repeatedly argued during his penalty phase
closing argument that the death penalty should be imposed
because Hamilton was a danger to society. Defense counsel
could have rebutted this argument by demonstrating that the
ongoing pattern of intergenerational abuse and the psycholog-
ical damage inflicted on Hamilton by his family made it
unlikely that he would have abused or killed anyone other
than a family member, and thus was not a danger to society
at large.

   Because counsel knew almost none of the relevant mitigat-
ing evidence, however, he committed errors during his closing
argument that compounded the prejudice caused by his failure
to investigate. The prosecution had reviewed each of the
eleven statutory factors that the jury was required to weigh in
assessing the appropriateness of the death penalty. See Cal.
Penal Code § 190.3 (West 1978). In addressing subsection
(d), “whether or not the offense was committed while the
defendant was under the influence of extreme mental or emo-
13642                     HAMILTON v. AYERS
tional disturbance,” the prosecution stated that “[t]here’s no
evidence certainly of any extreme mental or emotional distur-
bance.”19 The prosecution’s statement was accurate in light of
defense counsel’s meager penalty phase preparation and pre-
sentation, and defense counsel had no basis on which to rebut
it. Instead, he caused far more damage to his client than the
prosecution with only three short statements: “Mental disease
and intoxication is never an issue. It’s not a factor. It does not
need to be considered.” Defense counsel thus abruptly shut
the door on one of Hamilton’s strongest mitigation defenses
because he did not even know it existed.

   We therefore place on one side of the scale the mitigating
evidence adduced at trial and at the evidentiary hearing before
the district court. Weighed against this evidence is at most
two aggravating factors: Hamilton’s prior felony conviction
for grand theft,20 and the circumstances of the crime. These
factors alone do not tip the scale so far that no reasonable
juror could have voted against the death penalty. See Silva,
279 F.3d at 849 (“[I]n spite of the undeniably horrific circum-
stances surrounding [the crime], ‘this is not a case in which
a death sentence was inevitable because of the enormity of the
aggravating circumstances.’ ” (quoting Bean, 163 F.3d at
1081)). The prosecution conceded that the prior felony should
not “enter into the jury’s consideration.” Regardless, this rela-
tively minor offense would have been significantly out-
weighed by the available mitigating evidence.

   [27] Turning to the second factor, we do not dispute that
the circumstances of Hamilton’s crime were cold and calcu-
  19
      Although we do not reach Hamilton’s claim that errors committed by
the prosecution during the penalty phase constitute prosecutorial miscon-
duct, we note that the prosecution’s incorrect characterization of some of
the § 190.3 factors likely added to the prejudice that Hamilton suffered on
account of defense counsel’s mistakes.
   20
      Other than the record of this conviction, to which defense counsel had
stipulated, the prosecution presented no aggravating evidence at the pen-
alty phase.
                      HAMILTON v. AYERS                    13643
lating, motivated by personal desire and greed. Yet, even the
gruesome nature of a crime does “not necessarily mean the
death penalty [i]s unavoidable.” Douglas, 316 F.3d at 1091;
Hendricks, 70 F.3d at 1044 (rejecting the argument that the
substantial amount of aggravating evidence rendered the pre-
sentation of mitigating evidence futile, and noting that the fac-
tfinder in California has broad latitude to weigh the worth of
the defendant’s life). We have found that the defendant was
prejudiced by counsel’s deficient penalty phase investigation
and presentation in cases involving comparable or even far
more brutal crimes posing a greater threat to the public at
large. See, e.g., Douglas, 316 F.3d at 1082-83, 1091 (the
defendant raped, tortured, and killed two teenage girls and
buried them in the desert); Lambright, 490 F.3d at 1106-07,
1127-28 (the defendant watched as his codefendant repeatedly
raped the victim; the defendant then killed the victim by stab-
bing her multiple times and smashing her head with a rock);
Hovey v. Ayers, 458 F.3d 892, 898, 930 (9th Cir. 2006) (the
defendant abducted and killed an eight-year old girl; she was
found with numerous depressed skull fractures and laceration
wounds); Smith v. Stewart, 189 F.3d 1004, 1006, 1013-14 (9th
Cir. 1999) (the defendant raped two women; both victims
were stabbed repeatedly, punctured with needles, bound with
rope, suffocated by having dirt forced in their mouths, which
were then taped shut; the victims were left naked in the desert
to die, and one of them did). Given the compelling evidence
of Hamilton’s “excruciating life history” that could have been
placed “on the mitigating side of the scale,” Wiggins, 539
U.S. at 537, we conclude that “ ‘there is a reasonable proba-
bility that at least one juror would have struck a different bal-
ance’ between life and death,” Belmontes, 529 F.3d at 863
(quoting Wiggins, 539 U.S. at 537); see also Summerlin, 427
F.3d at 643-44.

   Our precedent does not direct us to a contrary conclusion.
In Allen v. Woodford, we held that counsel’s failure to present
any mitigating evidence was not prejudicial because the “hei-
nous nature” of the defendant’s crimes—murdering three peo-
13644                 HAMILTON v. AYERS
ple and conspiring to murder four others while already
serving a life sentence for yet another murder—was not out-
weighed by the available mitigating evidence. 395 F.3d 979,
1010 (9th Cir. 2005). Yet, unlike the evidence pertaining to
Hamilton’s abusive childhood and mental illness since at least
the age of twelve, the available mitigating evidence in Allen
was “entirely bereft of explanatory or exculpatory attributes.”
Id. at 1005. Instead, it “consisted primarily of testimony that
at some points in his life Allen had been nice to some people
and that some people cared for him.” Id. at 1007. In Allen, we
distinguished cases in which the jury was not presented with
mitigating evidence concerning an abusive childhood or other
traumatic experiences. Id. at 1005-07 (discussing Douglas,
Silva, Wiggins, and Mayfield).

   Woodford v. Visciotti, 537 U.S. 19 (2002) (per curiam), is
similarly inapposite. There, the defendant was convicted of “a
cold-blooded execution-style killing of one victim and
attempted execution-style killing of another, both during the
course of a preplanned armed robbery.” Id. at 26. His prior
offenses included “the knifing of one man, and the stabbing
of a pregnant woman as she lay in bed trying to protect her
unborn baby.” Id. Viewing the ineffective assistance claim
through the deferential lens of AEDPA, id. at 21, the Supreme
Court held that the state court’s conclusion that the defendant
failed to demonstrate prejudice was not objectively unreason-
able, id. at 26-27. The Court emphasized the relative weak-
ness of the available mitigating evidence. Id. at 26. The
defendant showed only that, as a child, he had been berated,
lacked self-esteem, moved frequently, and possibly had a sei-
zure disorder. His “troubled family background” did not
include any evidence of physical abuse or severe deprivation.
Id. Because, unlike here, the defendant’s childhood was not
marked by unimaginable horrors of which the jury should
have been made aware, Visciotti is readily distinguishable.
See also Bible v. Ryan, 571 F.3d 860, 872 (9th Cir. 2009)
(acknowledging that “significant aggravating circumstances
do not preclude a conclusion of prejudice,” but finding no
                      HAMILTON v. AYERS                    13645
prejudice where the mitigating evidence unearthed at the evi-
dentiary hearing was either speculative or cumulative of the
evidence presented at sentencing); Brown v. Ornoksi, 503
F.3d 1006, 1016 (9th Cir. 2007) (“To be sure, horrific facts
do not preclude a finding of prejudice . . . . But giving the
state court decision the deference it is due under AEDPA, we
cannot say that the California Supreme Court was objectively
unreasonable in concluding that Brown had not satisfied both
prongs of Strickland.” (citations omitted)).

   [28] The State has failed to demonstrate that the aggravat-
ing circumstances so outweighed the mitigating evidence as
to render the death penalty inevitable. As in Wiggins, “there
is a reasonable probability that at least one juror would have
struck a different balance” between life and death “[h]ad the
jury been able to place petitioner’s excruciating life history on
the mitigating side of the scale.” 539 U.S. at 537. Counsel’s
failure to investigate and present the ample mitigating evi-
dence thus “undermine[s] confidence in the outcome.” Strick-
land, 466 U.S. at 694. Therefore, we hold that Hamilton has
satisfied his burden of establishing prejudice.

                    IV.   CONCLUSION

   [29] Hamilton was constitutionally entitled to effective rep-
resentation at the penalty phase of his capital trial, but he did
not receive it. His counsel failed to investigate a substantial
amount of available mitigating evidence concerning Hamil-
ton’s horrific childhood and mental illness, and thus could not
possibly have made a strategic decision as to a mitigation
defense. Counsel compounded these errors by presenting only
one witness, Hamilton’s mother, whose testimony was likely
more harmful than helpful. “[C]ounsel’s duty is not dis-
charged merely by presenting some limited evidence. Rather,
a penalty phase ineffective assistance claim depends on the
magnitude of the discrepancy between what counsel did
investigate and present and what counsel could have investi-
gated and presented.” Stankewitz v. Woodford, 365 F.3d 706,
13646                  HAMILTON v. AYERS
716 (9th Cir. 2004). It is difficult to imagine a more signifi-
cant discrepancy than that between the portrait painted at the
penalty phase of a man whose childhood was “unfortunate”
but largely unmarred, and that of a child who was raised in
the presence of incest, rape, and violence, suffered from men-
tal illness, and was shuffled from home to home. Although
this classic mitigating evidence was available to defense
counsel at the time of trial, it was only revealed years after
Hamilton was sentenced to death. We therefore hold that
Hamilton was denied effective assistance of counsel. Accord-
ingly, we reverse the district court’s judgment and remand
with instructions to issue the writ and return the case to the
Tulare County Superior Court to reduce Hamilton’s sentence
to life imprisonment without the possibility of parole, unless
the State pursues a new sentencing proceeding within a rea-
sonable amount of time, as determined by the district court.
We affirm the district court’s denial of habeas relief as to guilt
phase issues.

 AFFIRMED in part; REVERSED in part; and
REMANDED.
