                  FOR PUBLICATION
  UNITED STATES COURT OF APPEALS
       FOR THE NINTH CIRCUIT

JEFFREY TIMOTHY LANDRIGAN, a.k.a.      
Billy Patrick Wayne Hill,
                                             No. 00-99011
               Petitioner-Appellant,
                                               D.C. No.
                 v.
                                          CV-96-02367-PHX-
DORA B. SCHRIRO, Director,                       ROS
Arizona Department of
                                               OPINION
Corrections,
              Respondent-Appellee.
                                       
        Appeal from the United States District Court
                 for the District of Arizona
         Roslyn O. Silver, District Judge, Presiding

             Argued and Submitted En Banc
        March 24, 2005—San Francisco, California
         Submission Withdrawn April 15, 2005
               Resubmitted March 1, 2006

                    Filed March 8, 2006

Before: Mary M. Schroeder, Chief Judge, Harry Pregerson,
Stephen Reinhardt, Alex Kozinski, Michael Daly Hawkins,
       Kim McLane Wardlaw, William A. Fletcher,
Marsha S. Berzon, Richard R. Clifton, Consuelo M. Callahan
            and Carlos T. Bea, Circuit Judges.

                Opinion by Judge Hawkins;
                  Dissent by Judge Bea




                            2329
                     LANDRIGAN v. SCHRIRO                 2333


                         COUNSEL

Dale A. Baich, Assistant Federal Public Defender, Phoenix,
Arizona, for the petitioner-appellant.

James P. Beene, Assistant Attorney General, Capital Litiga-
tion Section, Phoenix, Arizona, for the respondent-appellee.


                         OPINION

HAWKINS, Circuit Judge:

   In this appeal, we consider whether petitioner, Jeffrey Tim-
othy Landrigan, received ineffective assistance of counsel in
the penalty phase of his capital murder trial. We conclude
Landrigan has raised a colorable claim that his counsel’s per-
formance fell below the objective standard of reasonableness
2334                    LANDRIGAN v. SCHRIRO
required by Strickland v. Washington, 466 U.S. 668 (1984),
and that he was prejudiced by these errors. We therefore
remand to the district court to conduct an evidentiary hearing
on Landrigan’s claim.

                         BACKGROUND

   In 1989, Landrigan escaped from an Oklahoma prison and
soon thereafter murdered Chester Dean Dyer in Arizona. He
was convicted of first degree murder in Arizona state court
and sentenced to death. The Arizona Supreme Court affirmed
his conviction and sentence. Arizona v. Landrigan, 176 Ariz.
1, 8 (1993).1

   Landrigan filed a petition for post-conviction relief in the
Arizona Superior Court, urging that his counsel, Dennis Far-
rell, had been ineffective by failing to investigate and present
mitigating evidence at the sentencing proceeding. Landrigan
also requested an evidentiary hearing in connection with this
claim. The Superior Court denied the request for the hearing
and the petition, concluding that Landrigan could not argue
his counsel was ineffective at sentencing because he had
instructed his attorney not to present mitigating evidence. The
Arizona Supreme Court summarily denied the petition.

   Landrigan thereafter filed a petition for writ of habeas cor-
pus in federal district court raising a number of claims,
including ineffective assistance of counsel. Landrigan sought
to expand the record to include declarations by mental health
experts and persons familiar with Landrigan’s background,
and the district court granted this request in part. Landrigan
also sought an evidentiary hearing, but the district court
denied this request and also denied the petition on the merits.
The district court concluded that even if Landrigan’s counsel
  1
   For a more detailed description of the crime and state court proceed-
ings, see Landrigan, 176 Ariz. at 3-4.
                       LANDRIGAN v. SCHRIRO                      2335
was deficient, Landrigan had not demonstrated he suffered
prejudice from his counsel’s shortcomings.

   Landrigan appealed to this court. The district court granted
Landrigan a certificate of appealability on several claims,
including whether “Landrigan’s trial counsel was ineffective
at sentencing, depriving Landrigan of his rights under the
Fifth, Sixth, Eighth and Fourteenth Amendments.” A three-
judge panel affirmed the district court’s denial of the writ.
Landrigan v. Stewart, 272 F.3d 1221, 1223 (9th Cir. 2001).
We granted rehearing en banc. Landrigan v. Stewart, 397
F.3d 1235 (9th Cir. 2005).2

   Since the district court’s 1999 denial of the writ and Lan-
drigan’s request for an evidentiary hearing and the filing of
our now withdrawn panel opinion on November 28, 2001, the
Supreme Court has issued a number of significant decisions
regarding ineffective assistance of counsel claims. The Court
has clarified the duty of an attorney to develop and present
mitigating evidence, even when dealing with capital defen-
dants who are “uninterested in helping” or “even actively
obstructive” in developing a mitigation case, Rompilla v.
Beard, 125 S. Ct. 2456, 2462-63 (2005), and also has elabo-
rated on the appropriate measure of prejudice in a capital pen-
alty phase proceeding, see Wiggins v. Smith, 539 U.S. 510,
534-38 (2003). Viewing Landrigan’s claim in light of these
precedents, we find that Landrigan has made a colorable
claim that he did not receive effective assistance of counsel in
his sentencing. We therefore remand to the district court to
conduct an evidentiary hearing.

                                  I.

  We review the district court’s decision to deny habeas cor-
  2
   We initially heard argument in March 2005, but deferred submission
pending this court’s en banc decision in Summerlin v. Schriro, 427 F.3d
623 (9th Cir. 2005) (en banc).
2336                  LANDRIGAN v. SCHRIRO
pus relief de novo. Bribiesca v. Galaza, 215 F.3d 1015, 1018
(9th Cir. 2000). Because Landrigan filed his petition after
April 24, 1996, it is governed by the standard of review set
forth in the Antiterrorism and Effective Death Penalty Act of
1996 (“AEDPA”), 28 U.S.C. § 2254(d)(1). Under AEDPA,
Landrigan is entitled to a writ if the state court’s denial of his
claim “resulted in a decision that was contrary to, or involved
an unreasonable application of, clearly established Federal
law, as determined by the Supreme Court of the United
States.” Id.

   [1] The district court’s decision to deny an evidentiary
hearing is reviewed for an abuse of discretion. See Earp v.
Ornoski, 431 F.3d 1158, 1166 (9th Cir. 2005). Under
AEDPA, if a petitioner fails to develop in state court the fac-
tual basis for a claim, he is restricted in his ability to do so in
federal court. See 28 U.S.C. § 2254(e)(2). These restrictions
do not apply, however, if a petitioner exercised due diligence
in state court and attempted to develop the factual basis of his
claim. As the Supreme Court has explained, “a failure to
develop the factual basis of a claim is not established unless
there is lack of diligence, or some greater fault, attributable to
the prisoner or the prisoner’s counsel.” Michael Wayne Wil-
liams v. Taylor, 529 U.S. 420, 432 (2000). The Court has fur-
ther noted that “[d]iligence will require in the usual case that
the prisoner, at a minimum, seek an evidentiary hearing in
state court in the manner prescribed by state law.” Id. at 437.

   [2] Landrigan did not “fail to develop” the factual basis for
his ineffective assistance claim in state court. In his state
habeas petition, Landrigan made a general claim that his
counsel had failed to investigate and develop potential miti-
gating evidence, including his biological mother’s use of
drugs and alcohol during gestation, his adoptive mother’s
alcoholism and its adverse effect on Landrigan’s upbringing,
and information regarding his biological father and his family
history of violence. Landrigan sought the appointment of a
medical expert to assist in establishing mitigating evidence
                     LANDRIGAN v. SCHRIRO                  2337
regarding the effects of drug and alcohol use on a developing
fetus, and also requested an evidentiary hearing on his inef-
fective assistance claim. Landrigan supported his petition with
various declarations by available witnesses who attested they
were never contacted by Landrigan’s trial attorney, and with
documentary evidence regarding criminal psychobiology and
congenital determinants of violence. The state court denied
both the appointment of an expert and Landrigan’s request for
an evidentiary hearing.

   [3] Landrigan tried and failed, through no fault of his own,
to develop the facts supporting his ineffective assistance claim
at the state-court level. He is therefore not precluded by
AEDPA from seeking an evidentiary hearing in federal court.
See Earp, 431 F.3d at 1169; Jones v. Wood, 114 F.3d 1002,
1013 (9th Cir. 1997). In such circumstances, Landrigan is
entitled to an evidentiary hearing if he can establish a “color-
able claim” for relief. See Earp, 431 F.3d at 1173.

                              II.

   [4] The Sixth Amendment right to effective assistance of
counsel extends to the sentencing phase of a capital case.
Silva v. Woodford, 279 F.3d 825, 836 (9th Cir. 2002). We
analyze Landrigan’s claim that he was deprived of this right
pursuant to the standards set forth by the Supreme Court in
Strickland: Landrigan must demonstrate that his counsel’s
representation “fell below an objective standard of reason-
ableness” and that there is a reasonable probability that coun-
sel’s unprofessional errors “undermine confidence in the
outcome of the proceeding.” 466 U.S. at 688, 694.

                              A.

   [5] According to the prevailing standards at the time of
Landrigan’s sentencing, counsel had an obligation to conduct
a thorough investigation of the defendant’s background. See
Terry Williams v. Taylor, 529 U.S. 362, 396 (2000) (“T. Wil-
2338                  LANDRIGAN v. SCHRIRO
liams”) (citing 1 ABA Standards for Criminal Justice 4-4.1,
cmt. at p. 4-55 (2d ed. 1980)); Rompilla, 125 S. Ct. at 2466.
As this court has also noted, when it comes to the penalty
phase of a capital trial, “[i]t is imperative that all relevant mit-
igating information be unearthed for consideration.” Caro v.
Calderon, 165 F.3d 1223, 1227 (9th Cir. 1999). We begin by
considering what steps Landrigan’s counsel took in his inves-
tigation. See Wiggins, 539 U.S. at 522-23 (court should first
focus on whether the investigation is itself reasonable); Strick-
land, 466 U.S. at 690-91 (courts will defer to counsel’s
choices, if made after conducting a reasonable investigation).

1. On the record before us, it appears that Landrigan’s counsel
did little to prepare for the sentencing aspect of the case. He
did obtain several medical documents indicating Landrigan
had a long history of substance abuse and included this infor-
mation in Defendant’s Sentencing Memorandum Concerning
Mitigation. He also had a psychologist, Mickey McMahon,
evaluate Landrigan to obtain an “initial impression,” but did
not provide him with any relevant background information on
Landrigan to assist in the evaluation. See, e.g., Clabourne v.
Lewis, 64 F.3d 1373, 1385 (9th Cir. 1995) (counsel ineffec-
tive for inadequately preparing psychologist). Although the
psychologist recommended that he perform additional testing,
Farrell would not authorize any follow-up tests. Dr.
McMahon’s declaration describes his experience with Farrell
as “quite different from the working relationship I had with
counsel in other death penalty cases.”

   Landrigan’s counsel also hired an investigator, who spent
a total of thirteen hours on the case, but none of this work was
directed towards sentencing phase considerations. The inves-
tigator claims that he had very little interaction with counsel
about the case and that he found this “quite frustrating.”

  Prior to the sentencing, Farrell also spoke briefly with two
family members — Landrigan’s ex-wife and his birth mother.
At the sentencing hearing, Farrell advised the court that he
                     LANDRIGAN v. SCHRIRO                   2339
expected Landrigan’s ex-wife to verify Landrigan’s history of
substance abuse; state that Landrigan had been a loving, car-
ing husband; and explain the circumstances of one of Landri-
gan’s prior convictions. Farrell also proffered that
Landrigan’s birth mother would testify about her drug and
alcohol use during her pregnancy, and that after developing
this testimony, Farrell was then hoping to have a recess to talk
to some experts about the effect on the fetus. But even this
dialogue with the court revealed that he had not, during pre-
sentencing investigation, ascertained any specifics about Lan-
drigan’s mother’s drug use or contacted any experts on the
subject in advance of the hearing.

   [6] “[C]ounsel is not deficient for failing to find mitigating
evidence if, after a reasonable investigation, nothing has put
the counsel on notice of the existence of that evidence.” Bab-
bitt v. Calderon, 151 F.3d 1170, 1174 (9th Cir. 1998) (quoting
Matthews v. Evatt, 105 F.3d 907 (4th Cir. 1997)) (internal
quotation marks omitted). In this case, however, the initial
investigation did reveal potential mitigating evidence, but that
evidence was not developed. In addition to the evidence dis-
cussed above, Landrigan alleges that his birth mother sent a
letter to Farrell in April 1990, informing Farrell that, among
other things, (1) Landrigan began drinking at an early age
because his adoptive mother was an alcoholic and would walk
around nude in front of him, (2) Landrigan’s father was on
death row in Arkansas and the “blood link to Darrel [and] I
are what has messed up his whole life,” and (3) “Jeff needs
help mentally like his father did.” Despite these clues, Farrell
did not contact Landrigan’s birth father, secure a detailed
mental health evaluation, or develop a family or social history
regarding Landrigan’s upbringing in his adoptive home.

   Landrigan alleges that with some minimal investigation,
Farrell could have uncovered Landrigan’s tortured family his-
tory: Landrigan’s birth parents were troubled individuals who
abused drugs and alcohol; Landrigan’s biological father was
a violent man who, at the time of Landrigan’s trial, was on
2340                 LANDRIGAN v. SCHRIRO
death row in Arkansas; Landrigan’s mother abandoned Lan-
drigan when he was six months old, leaving him in a day nur-
sery and never returning; Landrigan was later adopted, but
unfortunately, his adoptive mother was also an alcoholic, at
times consuming a fifth of vodka or more a day until she
passed out; she would frequently slap him and once even hit
him with a frying pan; his childhood was difficult — he
exhibited abandonment and attachment problems, had diffi-
culty sleeping, and had violent temper tantrums even at a very
early age; Landrigan had serious drug and alcohol problems
while very young, and he even overdosed in class in eighth or
ninth grade; at the time he committed the murder in Arizona,
he had used amphetamines for forty-two straight days and had
slept on only about fourteen of those days.

   In 1998, following a thorough neuropsychological evalua-
tion, Dr. Thomas Thompson reported that the convergence of
the above-mentioned factors — Landrigan’s genetic makeup,
in utero exposure to teratogenic substances, early maternal
rejection, and his troubled interactions with his adoptive fam-
ily — resulted in disordered behavior that was “beyond the
control of Mr. Landrigan,” and left him unable to “function in
a society that expects individuals to operate in an organized
and adaptive manner, taking into account the actions and con-
sequences of their behavior and their impact on society and its
individual members.”

[7] 2. A comparison of the results of the minimal investiga-
tion by Farrell with the amount of available mitigating evi-
dence Landrigan claims was available leaves us with grave
doubts whether Landrigan received effective assistance of
counsel during his penalty phase proceeding. The state urges,
however, that Farrell’s investigatory shortcomings are irrele-
vant because Landrigan would not permit the introduction of
mitigating evidence in the sentencing phase of his trial.

  The state misreads what occurred at the sentencing hearing.
Landrigan’s counsel had lined up only two witnesses to testify
                    LANDRIGAN v. SCHRIRO                     2341
on his behalf during the sentencing phase: Landrigan’s ex-
wife and birth mother. Landrigan, however, opposed putting
them on the stand. His lawyer explained Landrigan’s wishes
to the sentencing judge as follows:

       MR. FARRELL: Your Honor, at this time . . . I
    have two witnesses that I wished to testify before
    this Court, one I had brought in from out of state and
    is my client’s ex-wife, Ms. Sandy Landrigan. The
    second witness is my client’s natural mother, Vir-
    ginia Gipson. I believe both of those people had
    some important evidence that I believed the Court
    should take into mitigation concerning my client.
    However, Mr. Landrigan has made it clear to me—
    Jeffrey, the defendant—that he does not wish anyone
    from his family to testify on his behalf today.

       I have talked with Sandra Landrigan, his ex-wife.
    I have talked a number of times with her and con-
    firmed what I thought was important evidence that
    she should present for the Court. And I have also
    talked with Ms. Gipson, and her evidence I think is
    very important and should have been brought to this
    Court’s attention. Both of them, after talking with
    Jeff today, have agreed with their, in one case son
    and the other ex-husband, they will not testify in his
    behalf.

      THE COURT: Why not?

       MR. FARRELL: Basically it’s at my client’s
    wishes, Your Honor. I told him that in order to effec-
    tively represent him, especially concerning the fact
    that the State is seeking the death penalty, any and
    all mitigating factors, I was under a duty to disclose
    those factors to this Court for consideration regard-
    ing the sentencing. He is adamant he does not want
    any testimony from his family, specifically these two
2342                    LANDRIGAN v. SCHRIRO
      people that I have here, his mother, under subpoena,
      and as well as having flown in his ex-wife.

         I have advised him and I have advised him very
      strongly that I think it’s very much against his inter-
      ests to take that particular position. I have also
      advised both the witnesses I could have them sworn
      in and ask them questions, but they are under an
      obligation to do what they feel is right, Your Honor.
      They are looking after Jeff’s interests.

        I’m coming from the position that I have to bring
      certain evidence before this Court. I’m at a loss. I
      don’t know what this Court wishes to do.

[Emphasis added.]

   [8] The state trial court was thus confronted with a situation
where the defense lawyer had only prepared to present two
mitigation witnesses—Landrigan’s ex-wife and birth mother
—and Landrigan objected to putting them on the stand. It is
clear from this statement by counsel that Landrigan was
unwilling to have these two particular people testify, but there
is no mention of any other witnesses, and there is no indica-
tion that Landrigan would have precluded the introduction of
mitigating evidence by other means.3 The possibility of other
evidence or witnesses simply never came up, doubtless
because defense counsel had no other evidence to present.

  The colloquy that followed between the sentencing judge
and Landrigan must be read against this backdrop:
  3
    See Summerlin, 427 F.3d at 637-39 (spontaneous objection to presenta-
tion of one witness does not excuse failure to present penalty phase
defense); Stankewitz v. Woodford, 365 F.3d 706, 721-22 (9th Cir. 2004)
(opposition to calling family members or experts as witnesses does not
excuse an attorney from interviewing experts and family members to
obtain mitigating evidence).
                    LANDRIGAN v. SCHRIRO                 2343
      THE COURT: Mr. Landrigan, have you instructed
    your lawyer that you do not wish for him to bring
    any mitigating circumstances to my attention?

       THE DEFENDANT: Yeah.

       THE COURT: Do you know what that means?

       THE DEFENDANT: Yeah.

       THE COURT: Mr. Landrigan, are there mitigating
    circumstances I should be aware of?

       THE DEFENDANT: Not as far as I’m concerned.

   At the time the sentencing judge asked Landrigan whether
he instructed his lawyer not to present any mitigating circum-
stances, the only mitigating evidence that the lawyer could
have brought to the court’s attention was the testimony of the
two witnesses. Landrigan’s response to the court’s rather
vague question cannot, in context, be construed as anything
more than confirmation that he did not want his birth mother
and ex-wife testifying on his behalf. Indeed, due to his law-
yer’s meager investigation, there was no other mitigating evi-
dence available to which Landrigan could object or not object.

   When the sentencing judge then asked Landrigan whether
there were any other mitigating circumstances to be taken into
account, Landrigan replied that there were not. This, of
course, was a direct consequence of the fact that his counsel
had not presented him with any options other than the two
witnesses he opposed. Had his lawyer conducted an investiga-
tion and uncovered other types of mitigating evidence, Lan-
drigan might well have been able to direct the court to other
mitigating circumstances. Viewing the entire colloquy in
proper context, it is clear that the sentencing judge was only
inquiring about Landrigan’s willingness to allow his birth
2344                     LANDRIGAN v. SCHRIRO
mother and ex-wife to testify, and that Landrigan simply con-
firmed that he was not.

   [9] It was not until the Arizona Supreme Court (on direct
appeal) and the Arizona Superior Court (on habeas review)
examined the colloquy that the sentencing judge’s questioning
was taken out of context. The state supreme court found that,
“[a]t the sentencing hearing, defendant instructed his lawyer
not to present any mitigating evidence.” And the state habeas
court similarly found that Landrigan “instructed his attorney
not to present any evidence at the sentencing hearing.” In
light of what actually transpired at the sentencing hearing,
such an overly broad characterization of the colloquy is not
supported by the record and thus amounts to an “unreasonable
determination of the facts.” 28 U.S.C. § 2254(d)(2).

[10] 3. Even were we to overlook the state habeas court’s
flawed factual finding that Landrigan unequivocally waived
presentation of all mitigating evidence, the court’s conclusion
that Landrigan’s claim was therefore necessarily “frivolous”
and “meritless” was an unreasonable application of United
States Supreme Court precedent. See id. § 2254(d)(1). Landri-
gan’s apparently last-minute decision cannot excuse his coun-
sel’s failure to conduct an adequate investigation prior to the
sentencing. Cf. Wiggins, 539 U.S. at 522-23 (focus should be
on whether investigation was itself reasonable, not whether
counsel should have presented a mitigation case);4 see also
Stankewitz, 365 F.3d at 722 (counsel has duty to investigate
what evidence potentially could have been presented and dis-
cuss this evidence with accused in order to obtain an informed
  4
    Although Wiggins is a recent Supreme Court case, it applied the famil-
iar Strickland inquiry applicable to ineffective assistance claims in a post-
AEDPA case. Indeed, the Court in Wiggins expressly stated that the case
presented the same issue as in Strickland and that it was applying the
“clearly established precedent of Strickland.” 539 U.S. at 521. Wiggins’s
trial took place in 1989, one year prior to Landrigan’s 1990 trial. Id. at
514-15. Therefore, the Court’s reasoning in Wiggins is fully applicable to
Landrigan’s case.
                     LANDRIGAN v. SCHRIRO                   2345
and knowing waiver); Silva, 279 F.3d at 839-40 (instruction
not to call parents as witnesses did not preclude counsel from
investigating background). There is no indication in the cur-
rent record that Landrigan in any way prohibited or impeded
Farrell’s ability to investigate or assemble a mitigation
defense. And even if he had, the prevailing standards, even at
the time of Landrigan’s trial, “suggest that a lawyer’s duty to
investigate is virtually absolute, regardless of a client’s
expressed wishes.” Silva, 279 F.3d at 840 (citing 1 ABA Stan-
dards for Criminal Justice 4-4.1 cmt. at 4-55); see also T. Wil-
liams, 529 U.S. at 396 (citing same).

   [11] Nor does the record indicate that Landrigan’s decision
was informed and knowing. It is “difficult for an attorney to
advise a client of the prospects of success or the potential con-
sequences of failing to present mitigating evidence when the
attorney does not know that such evidence exists.” Douglas
v. Woodford, 316 F.3d 1079, 1089 (9th Cir. 2003); see also
Stankewitz, 365 F.3d at 722 (petitioner’s objection to mitigat-
ing evidence apparently not “informed and knowing” because
counsel did not conduct an adequate investigation). The trial
court’s dialogue with Landrigan tells us little about his under-
standing of the consequences of his decision: After asking
whether Landrigan had instructed his attorney not to present
mitigating circumstances, the court asked only, “Do you know
what that means?” Landrigan simply responded, “Yeah.”
There was no further exploration by the court into Landri-
gan’s understanding, or what advice his attorney had given
him outside of court.

  As we recently explained:

    If a client has elected to forego legal proceedings
    that could avert the imposition of the death penalty,
    then a court must make the determination “whether
    he has capacity to appreciate his position and make
    a rational choice with respect to continuing or aban-
    doning further litigation or on the other hand
2346                  LANDRIGAN v. SCHRIRO
    whether he is suffering from a mental disease, disor-
    der, or defect which may substantially affect his
    capacity in the premises.”

Summerlin, 427 F.3d at 639 (quoting Rees v. Peyton, 384 U.S.
312, 314 (1966)). The trial court’s cursory inquiry into Lan-
drigan’s purported waiver of all mitigating evidence did not
satisfy this requirement.

   [12] For all of the foregoing reasons, Landrigan has not
waived the right to assert a claim for ineffective assistance of
counsel. Moreover, Landrigan has alleged facts that, if true,
would establish that his counsel was ineffective for failing to
investigate and discover important mitigating evidence. This
alone, however, would not entitle Landrigan to habeas relief
or even to an evidentiary hearing. We therefore turn to the
issue of prejudice.

                               B.

   To establish prejudice, Landrigan must demonstrate a rea-
sonable probability that Farrell’s deficiencies “undermine
confidence in the outcome” of the proceeding. Strickland, 466
U.S. at 694 (“A reasonable probability is a probability suffi-
cient to undermine confidence in the outcome.”) To assess
prejudice in a capital penalty phase proceeding, the Supreme
Court has directed us to “reweigh the evidence in aggravation
against the totality of available mitigating evidence.” Wiggins,
539 U.S. at 534.

   That evidence includes both the evidence adduced at trial
and the evidence adduced in habeas proceedings. See id. at
536; T. Williams, 529 U.S. at 397-98. In evaluating prejudice,
the district court improperly refused to consider additional
facts proffered by Landrigan, such as expert testimony regard-
ing Landrigan’s organic brain dysfunction, because the court
erroneously concluded that Landrigan had failed to exhaust
this claim in state court. In state court, Landrigan asserted that
                     LANDRIGAN v. SCHRIRO                  2347
his counsel was ineffective because Farrell had failed to
undertake a reasonable investigation of mitigating factors,
including information that could have been derived from Lan-
drigan’s biological father and his adoptive sister. Landrigan
summarized his claim as follows:

    Where a defendant’s crime is attributable to a disad-
    vantaged background or emotional or mental prob-
    lems the defendant is less culpable than one without
    the excuse. California v. Brown, 479 U.S. 538, 545
    (1987) (O’Connor, J., concurring). See also, State v.
    Wallace, 160 Ariz. 424, 427, 773 P.2d 983, 986
    (1989), cert. denied, 494 U.S. 1047 (1990). Due to
    ineffective assistance from trial counsel at sentenc-
    ing, this Honorable Court did not have a complete
    and accurate picture of Petitioner’s background.

   The additional information offered by Landrigan in support
of his federal habeas claim does not “fundamentally alter” the
ineffective assistance claim presented to the state court. It
simply provides additional evidentiary support for the claim,
in particular with respect to the prejudice prong of Strickland.
See Vasquez v. Hillery, 474 U.S. 254, 260 (1986); see also
Belmontes v. Brown, 414 F.3d 1094, 1117-18 (9th Cir. 2005)
(“[N]ew factual allegations do not render a claim unexhausted
unless they fundamentally alter the legal claim already con-
sidered by the state courts.” (quoting Chacon v. Wood, 36
F.3d 1459, 1468 (9th Cir. 1994) (quoting Vasquez, 474 U.S.
at 260))) (internal quotation marks omitted).

   [13] As discussed above, there was a significant amount of
potential mitigating evidence that was not unearthed or pres-
ented to the sentencing judge. Landrigan alleges he was
exposed to alcohol and drugs in utero, which may have
resulted in cognitive and behavioral deficiencies consistent
with fetal alcohol syndrome. He was abandoned by his birth
mother and suffered abandonment and attachment issues, as
well as other behavioral problems throughout his childhood.
2348                     LANDRIGAN v. SCHRIRO
His adoptive mother was also an alcoholic, and Landrigan’s
own alcohol and substance abuse began at an early age. Based
on his biological family’s history of violence, Landrigan
claims he may also have been genetically predisposed to vio-
lence.

   [14] If true, Landrigan’s allegations are “the very sort of
mitigating evidence that ‘might well have influenced the
[judge’s] appraisal of [Landrigan’s] moral culpability.’ ”
Earp, 431 F.3d at 1179 (quoting T. Williams, 529 U.S. at
398). “Evidence regarding social background and mental
health is significant, as there is a ‘belief, long held by this
society, that defendants who commit criminal acts that are
attributable to a disadvantaged background or to emotional or
mental problems, may be less culpable than defendants who
have no such excuse.’ ” Douglas, 316 F.3d at 1090 (quoting
Boyde v. California, 494 U.S. 370, 382 (1990)).5 We also note
that in finding Landrigan’s background or emotional character
was not a mitigating circumstance, the state sentencing judge
specifically noted that he had “received very little information
concerning the defendant’s difficult family history,” implying
a more complete picture could have tipped the scale in Lan-
drigan’s favor.

   In comparison, there were two aggravating circumstances
relied upon by the sentencing judge: (1) the defendant had
  5
    The dissent seizes upon Landrigan’s expert’s diagnosis of antisocial
personality disorder and analyzes whether such a disorder is sufficient to
justify mitigation. [Dissent at 2351-52]. Yet this diagnosis is only a small
piece of the puzzle; the crux of Landrigan’s argument is that the sentenc-
ing judge was never apprised of the full panoply of circumstances that, in
the expert’s opinion, converged to result in “disordered behavior [that]
was beyond the control of Mr. Landrigan.” The dissent also suggests that
Landrigan’s trial behavior would have negated any attempt to elicit sym-
pathy [Dissent at 2353-55], yet Landrigan contends this behavior was con-
sistent with the expert’s analysis of limited impulse control and an
inability to take into account the consequences of his behavior. Indeed, if
Landrigan’s counsel had offered such mental health information, it could
have actually explained his courtroom behavior and tempered its effect.
                     LANDRIGAN v. SCHRIRO                  2349
prior felony convictions involving the use or threatened use of
violence on another person, and (2) the defendant committed
the offense with the expectation of receiving pecuniary gain.
See Ariz. Rev. Stat. §§ 13-703(F)(2), (5). There was limited
evidence regarding the pecuniary gain aggravator. The judge
noted that the victim’s apartment had been ransacked as if the
perpetrator were looking for something, and that this demon-
strated an expectation of pecuniary gain, even though Landri-
gan did not actually steal anything of value. On the other
hand, Landrigan had been previously convicted of two violent
crimes — second degree murder for the stabbing death of an
individual in Oklahoma and assault and battery with a deadly
weapon for stabbing another inmate while serving his second
degree murder sentence.

   [15] Notwithstanding these obviously serious prior
offenses, Landrigan still may have been prejudiced by his
attorney’s alleged shortcomings. Even in cases involving par-
ticularly heinous murders, or substantial criminal histories, a
defendant can be prejudiced by an attorney’s failure to inves-
tigate and present mitigating evidence that could influence the
judge’s appraisal of moral culpability. See T. Williams, 529
U.S. at 398; Stankewitz, 365 F.3d at 724 (mitigating evidence
could have fostered sympathy for defendant and could also
have diminished the aggravating impact of the prosecution’s
case). Presented with the additional mitigating evidence
regarding Landrigan’s background and emotional and mental
problems, there is a reasonable probability that, if Landrigan’s
allegations are true, the sentencing judge would have reached
a different conclusion.

                              III.

   Of course, to this point, Landrigan’s evidence has not been
tested. Farrell has not been given an opportunity to explain
what steps were taken in his investigation or why he did not
do more; Landrigan’s accounts of his childhood have not been
explored; and the state has not had an opportunity to cross-
2350                     LANDRIGAN v. SCHRIRO
examine his experts or challenge the strength of their opin-
ions. We note this only to emphasize that we are not opining
on what the district court’s ultimate resolution of this issue
should be; we conclude only that Landrigan has surpassed the
relatively “low bar” of alleging a colorable claim for relief.
Earp, 431 F.3d at 1170.

   [16] We conclude Landrigan has alleged facts that, if dem-
onstrated to be true, present a colorable claim that he received
ineffective assistance of counsel in his capital sentencing pro-
ceeding. Landrigan has demonstrated a proper basis for an
evidentiary hearing.6

  AFFIRMED in part, REVERSED                            in    part,    and
REMANDED for an evidentiary hearing.



BEA, Circuit Judge, with whom Circuit Judge Callahan joins,
dissenting:

   Although I agree with the majority’s conclusion that coun-
sel’s limited investigation of Landrigan’s background fell
below the standards of professional representation prevailing
in 1990, I would not remand this case for an evidentiary hear-
ing because Landrigan has failed to allege facts that, if
proven, would demonstrate Strickland prejudice.

   We “review de novo [a] district court’s interpretation of
AEDPA standards governing the grant or denial of an eviden-
tiary hearing.” Earp, 431 F.3d at 1166. We may reverse the
denial of an evidentiary hearing only if the district court
abused its discretion. Id.
  6
    We adopt the panel’s holdings with respect to the additional sentencing
issues raised in Landrigan’s certificate of appealability. 272 F.3d at 1229-
31.
                         LANDRIGAN v. SCHRIRO                         2351
   To establish entitlement to an evidentiary hearing, Landri-
gan must demonstrate an objectively reasonable probability
that, had counsel proved the mitigating facts now alleged, the
sentencing judge would not have imposed the death penalty.
See Summerlin, 427 F.3d at 643. Landrigan alleges that his
birth mother exposed him to alcohol and drugs in utero and
later abandoned him, that he has a genetic predisposition for
violence, that his adoptive mother was an alcoholic, and that,
as a result of all these factors, he has antisocial personality disor-
der.1 Whether these alleged facts create an objectively reason-
able probability that Landrigan would have received a
different sentence must be considered in light of the particular
circumstances of his case. See Smith v. Stewart, 140 F.3d
1263, 1270 (9th Cir. 1998) (explaining that the mitigating
effect of antisocial personality disorder is context-dependent
and that, in Arizona, the disorder “has often been treated on
appeal as insufficient to justify mitigation”). Under these stan-
dards, three separate factors convince me there is no reason-
able probability that Landrigan would have received a
different sentence had his counsel proved the mitigating facts
now alleged.

   First, the mitigating effect of antisocial personality disorder
is greater when there is evidence that the disorder “controlled
[the] defendant’s conduct or impaired his mental capacity”
than when evidence suggests that, at the time of the crime, the
defendant “possessed the ability to restrain himself.” State v.
Brewer, 826 P.2d 783, 802-03 (Ariz. 1992). For example, in
Brewer, the defendant’s antisocial personality disorder was
  1
   Contrary to the majority’s contention, to focus on the potential mitigat-
ing effect of Landrigan’s purported antisocial personality disorder is not
to “seize” on a “small piece” of some larger “puzzle” of mitigating cir-
cumstances that counsel failed to investigate or present. Maj. Op. at 2348
n.5. As the majority opinion itself acknowledges, all the mitigating cir-
cumstances Landrigan faults counsel for not raising “converge” to support
the suggestion that he suffers from antisocial personality disorder and can-
not control his actions. See id. at 2340. Antisocial personality disorder is
the crux of Landrigan’s ineffective assistance of counsel claim.
2352                 LANDRIGAN v. SCHRIRO
insufficient to tilt the balance of mitigating and aggravating
factors in favor of leniency because, notwithstanding his dis-
order, he had “resisted whatever impulses he may have expe-
rienced long enough to insure his own safety by locking the
[victim’s] roommate’s dog in another room before commenc-
ing his attack on the victim.” Id. at 803.

   Here, Landrigan has submitted an expert declaration sug-
gesting in passing that because of his antisocial personality
disorder he has “very limited impulse control.” The evidence,
however, is that on the occasion of the murder at issue Landri-
gan was able to control his impulses long enough to cultivate
the victim’s trust and attempt to profit from their encounter.
The trial testimony of one of the victim’s friends, “Michael,”
was that prior to the murder the victim called him three times.
During the first phone call, the victim reported that he and
Landrigan were together drinking beer. Approximately fifteen
minutes later, the victim called a second time to say he was
in the middle of sexual intercourse with Landrigan. Shortly
thereafter, the victim called to ask whether Michael could get
Landrigan a job. Thus, just as the defendant in Brewer was
able to control his impulses long enough to take steps to pro-
tect his physical safety, Michael’s testimony suggests Landri-
gan was able to control his murderous impulses long enough
to earn his victim’s trust, engage him in sexual relations, and
allow the victim to try to get him a job. This evidence dimin-
ishes the mitigating effect of his alleged antisocial personality
disorder.

   Second, as the three-judge panel that initially heard Landri-
gan’s appeal correctly recognized, in Landrigan’s case the
mitigating value of any proven genetic predisposition for vio-
lence would not have outweighed its aggravating tendency to
suggest Landrigan was undeterrable and, even from prison,
would present a future danger to society. Landrigan v. Stew-
art, 272 F.3d 1221, 1228-29 (9th Cir. 2001). One of the two
statutory aggravating factors the sentencing judge found was
that Landrigan had prior felony convictions involving the use
                     LANDRIGAN v. SCHRIRO                  2353
or threatened use of violence on another person. See Ariz.
Rev. Stat. § 13-703(F)(2). Landrigan had murdered his best
friend and then, while incarcerated for that crime, had brutally
stabbed a fellow inmate. In light of this history, and the fact
that Landrigan committed the murder for which he was con-
victed in the present case after escaping from prison, the
potential for future dangerousness—including peril to future
fellow inmates—inherent in Landrigan’s alleged genetic pre-
disposition for violence would have negated its mitigating
capacity for evoking compassion in the sentencing judge. See
People v. Franklin, 656 N.E.2d 750, 761 (Ill. 1995)
(“Although this evidence [regarding defendant’s psychologi-
cal problems and violent family history] could have evoked
compassion in the jurors, it could have also demonstrated
defendant’s potential for future dangerousness and the basis
for defendant’s past criminal acts. The evidence of defen-
dant’s mental illness may also have shown that defendant was
less deterrable or that society needed to be protected from
him.”).

   Third, but by no means least, Landrigan’s behavior at trial
would have negated any effort by counsel to elicit sympathy
based on a genetic or biological predisposition toward vio-
lence. The three-judge panel that originally heard this appeal
aptly described Landrigan’s behavior as follows:

       Landrigan was not willing to merely express his
    opinions to counsel and, once having given those
    indications about his feelings, recede into compara-
    tive silence as counsel went about the business of
    conducting the proceeding. Quite the contrary; Lan-
    drigan took an actively aggressive posture, which
    ensured that counsel’s attempts to place mitigating
    factors before the sentencing court would come a
    cropper. Each of counsel’s feints in the mitigation
    direction brought a statement from Landrigan that
    painted an even bleaker picture and made matters
    even worse. But we will not merely resort to charac-
2354                LANDRIGAN v. SCHRIRO
    terization; we will illustrate the situation with Lan-
    drigan’s own words.

       In an attempt to soften the effect of the fact that
    Landrigan had previously murdered his best friend,
    Greg Brown, counsel said that as Landrigan was
    walking away, Brown, a much larger man, rushed up
    and attacked him. Landrigan, who happened to be
    carrying a knife, defended himself and unfortunately
    killed Brown. A plausible story, but Landrigan
    would have none of it. His attorney got it all wrong.
    Rather, said he, “When we left the trailer, Greg went
    out of the trailer first. My wife was between us. I
    pulled my knife out, then I was the one who pushed
    her aside and jumped him and stabbed him. He
    didn’t grab me. I stabbed him.” In other words, Lan-
    drigan had come from behind and acted in a murder-
    ous way. That was all there was to it.

       Landrigan behaved similarly when counsel tried to
    envelop the assault on another prison inmate in a
    brume of self defense by suggesting that Landrigan
    had been threatened by the victim, who was a friend
    of Greg Brown and Greg’s father. Landrigan
    responded thusly: “That wasn’t Greg Brown’s dad’s
    friend or nothing like that. It was a guy I got in an
    argument with. I stabbed him 14 times. It was lucky
    he lived. But two weeks later they found him hung
    in his cell.” Again, Landrigan had unnecessarily
    behaved in an extremely violent and murderous way
    toward another human being.

      And when counsel tried to burnish Landrigan’s
    benighted past by indicating that before Brown’s
    murder, Landrigan, for at least one brief shining
    moment, was a “loving, caring husband,” who had
    married and was taking care of his wife and her child
    by “working . . . at a golf course during the year-and-
                          LANDRIGAN v. SCHRIRO                          2355
      a-half” preceding the killing, Landrigan demurred.
      He explained: “Well, I wasn’t just working. I was
      doing robberies supporting my family. We wasn’t
      married. We wasn’t married in Arizona. We lived in
      Oklahoma. I mean, you know, he’s not getting the
      story straight. Why have him tell somebody else’s
      story in the first fucking place?”

        If that were not enough, Landrigan made the fol-
      lowing presentation when the court asked if he
      would like to say anything in his own behalf:

            Yeah. I’d like to point out a few things
            about how I feel about the way this shit,
            this whole scenario went down. I think that
            it’s pretty fucking ridiculous to let a fagot
            be the one to determine my fate, about how
            they come across in his defense, about I
            was supposedly fucking this dude. This
            never happened. I think the whole thing
            stinks. I think if you want to give me the
            death penalty, just bring it right on. I’m
            ready for it.

Landrigan, 272 F.3d at 1226-27.2

   In light of (1) the evidence that Landrigan could and did
control his murderous impulses, (2) the probability that any
mitigating value of evidence of genetic or biological predispo-
sition for violence would have been overwhelmed by the evi-
  2
   It appears that Landrigan continues to question his counsel’s
approaches to this case, as indicated by his hand-written letter to this court
of August 16, 2005, stating:
      As of today, I want to withdraw my petition and drop all appeals.
      I no longer wish to pursue any action from your court or any oth-
      ers, and want my execution date to be set as soon as possible.
      Thank you.
2356                LANDRIGAN v. SCHRIRO
dence’s aggravating tendency to show that Landrigan was
undeterrable, and (3) Landrigan’s menacing behavior at trial,
Landrigan has not alleged facts that if proven would create an
objectively reasonable probability that he would have
received a different sentence. Accordingly, it was not an
abuse of discretion for the district court to deny him an evi-
dentiary hearing. I would affirm the district court’s decision
in its entirety.
