                FOR PUBLICATION

  UNITED STATES COURT OF APPEALS
       FOR THE NINTH CIRCUIT


ROBERT ALLEN POYSON ,                    No. 10-99005
             Petitioner-Appellant,
                                           D.C. No.
                 v.                     2:04-cv-00534-
                                            NVW
CHARLES L. RYAN ,
             Respondent-Appellee.
                                           OPINION


      Appeal from the United States District Court
               for the District of Arizona
        Neil V. Wake, District Judge, Presiding

                Argued and Submitted
     February 15, 2012—San Francisco, California

                 Filed March 22, 2013

    Before: Sidney R. Thomas, Raymond C. Fisher,
         and Sandra S. Ikuta, Circuit Judges.

                Opinion by Judge Fisher;
Partial Concurrence and Partial Dissent by Judge Thomas
2                        POYSON V . RYAN

                           SUMMARY*


                Habeas Corpus/Death Penalty

    The panel affirmed the district court’s denial of a 28
U.S.C. § 2254 habeas corpus petition by an Arizona state
prisoner challenging a conviction and capital sentence for
murder.

    The panel first held that the Arizona Supreme Court did
not deny petitioner his right to individualized sentencing by
applying an unconstitutional causal nexus test to potentially
mitigating evidence, because the panel could not presume a
constitutional violation from an ambiguous record that did
not reveal whether the court applied such a test as an
unconstitutional screening mechanism or as a permissible
means of determining the weight or significance of mitigating
evidence.

    The panel next denied relief on petitioner’s claim that the
Arizona courts failed to consider his history of substance
abuse as a nonstatutory mitigating factor. The panel
explained that the state courts considered the evidence and
found it wanting as a matter of fact because it failed to prove
a history of substance abuse, and that the state supreme court
did not misconstrue the state trial court’s findings so as to
deny petitioner of meaningful appellate review.

    Finally, the panel agreed with the district court that
petitioner’s ineffective assistance of counsel claim is

  *
    This summary constitutes no part of the opinion of the court. It has
been prepared by court staff for the convenience of the reader.
                       POYSON V . RYAN                         3

procedurally defaulted because it is fundamentally different
from the claim presented in state court such that the state
courts had no meaningful opportunity to consider it.

    Judge Thomas concurred in part, but dissented because he
would hold that the state court unconstitutionally excluded
mitigating evidence from consideration because it was not
causally related to the crimes.


                         COUNSEL

Jon M. Sands, Federal Public Defender, Michael L. Burke
(argued), Assistant Federal Public Defender, Ngozi V.
Ndulue, Assistant Federal Public Defender, Phoenix, Arizona,
for Petitioner-Appellant.

Thomas C. Horne, Attorney General, Kent Cattani, Division
Chief, Criminal Appeals/Capital Litigation Division, Jon G.
Anderson (argued), Assistant Attorney General, Capital
Litigation Section, Phoenix, Arizona, for Respondent-
Appellee.


                          OPINION

FISHER, Circuit Judge:

    Robert Allen Poyson was convicted of murder and
sentenced to death in 1998. After pursuing direct review and
seeking postconviction relief in state court, he filed a habeas
petition in federal district court. The district court denied the
petition, and Poyson appeals.
4                      POYSON V . RYAN

    Poyson raises three claims on appeal, each of which has
been certified by the district court pursuant to Fed. R. App. P.
22(b) and 28 U.S.C. § 2253(c): (1) the Arizona courts applied
an unconstitutional causal nexus test to mitigating evidence;
(2) the Arizona courts failed to consider mitigating evidence
of his history of substance abuse; and (3) his trial counsel
provided ineffective assistance of counsel during the penalty
phase of his trial by failing to investigate the possibility that
he suffered from fetal alcohol spectrum disorder. We
conclude the first two claims are without merit and the third
is procedurally defaulted. Accordingly, we affirm.

    The Arizona Supreme Court did not deny Poyson his right
to individualized sentencing by applying an unconstitutional
causal nexus screening test to potentially mitigating evidence.
Under our case law, we cannot hold that a state court
employed an unconstitutional nexus test “[a]bsent a clear
indication in the record that the state court applied the wrong
standard.” Schad v. Ryan, 671 F.3d 708, 724 (9th Cir. 2011)
(per curiam). The record here shows that the Arizona
Supreme Court considered the absence of a causal connection
to the murders in evaluating Poyson’s mitigating evidence,
but it does not reveal whether the court applied a nexus test
as an unconstitutional screening mechanism or as a
permissible means of determining the weight or significance
of mitigating evidence. See Lopez v. Ryan, 630 F.3d 1198,
1203–04 (9th Cir. 2011). We therefore must hold that the
Arizona Supreme Court’s decision was not “contrary to”
Supreme Court precedent under 28 U.S.C. § 2254(d)(1). See
Schad, 671 F.3d at 723–24.

   We also deny habeas relief on Poyson’s claim that the
Arizona courts failed to consider his history of substance
abuse as a nonstatutory mitigating factor. Poyson argues that
                      POYSON V . RYAN                        5

the state courts unconstitutionally refused to consider
mitigating evidence, a claim arising under Lockett v. Ohio,
438 U.S. 586 (1978), and Eddings v. Oklahoma, 455 U.S. 104
(1982). The state courts, however, did consider the evidence.
They simply found it wanting as a matter of fact, finding that
the evidence failed to prove a history of substance abuse.
There was therefore no constitutional violation under Lockett
and Eddings. Nor was there a constitutional violation under
Parker v. Dugger, 498 U.S. 308, 321 (1991). The state
supreme court did not misconstrue the state trial court’s
findings, so it did not deprive Poyson of meaningful appellate
review of his death sentence.

    Finally, we agree with the district court that Poyson’s
ineffective assistance of counsel claim is procedurally
defaulted because it is fundamentally different from the claim
presented in state court. Although it is true that “new factual
allegations do not ordinarily render a claim unexhausted, a
petitioner may not ‘fundamentally alter the legal claim
already considered by the state courts.’” Beaty v. Stewart,
303 F.3d 975, 989–90 (9th Cir. 2002) (quoting Vasquez v.
Hillery, 474 U.S. 254, 260 (1986)). Poyson’s federal petition
raises a theory of deficient performance – failure to
investigate and present mitigating evidence of fetal alcohol
spectrum disorder – that the state courts had no “meaningful
opportunity to consider.” Vasquez, 474 U.S. at 257. The
claim is therefore procedurally defaulted.

                    I. BACKGROUND

A. The Crimes

   Poyson was born in August 1976. The facts of his crimes,
committed in 1996, were summarized as follows by the
6                     POYSON V . RYAN

Arizona Supreme Court in State v. Poyson, 7 P.3d 79, 83
(Ariz. 2000).

    Poyson met Leta Kagen, her 15 year-old son, Robert
Delahunt, and Roland Wear in April 1996. Poyson was then
19 years old and homeless. Kagen allowed him to stay with
her and the others at their trailer in Golden Valley, near
Kingman, Arizona. In August of the same year, Kagen was
introduced to 48 year-old Frank Anderson and his 14 year-old
girlfriend, Kimberly Lane. They, too, needed a place to live,
and Kagen invited them to stay at the trailer.

    Anderson informed Poyson that he was eager to travel to
Chicago, where he claimed to have organized crime
connections. Because none of them had a way of getting to
Chicago, Anderson, Poyson and Lane formulated a plan to
kill Kagen, Delahunt and Wear in order to steal the latter’s
truck.

    On the evening of August 13, 1996, Lane lured Delahunt
into a small travel trailer on the property, ostensibly for sex.
There, Anderson commenced an attack on the boy by slitting
his throat with a bread knife. Poyson heard Delahunt’s
screams and ran to the travel trailer. While Anderson held
Delahunt down, Poyson bashed his head against the floor.
Poyson also beat Delahunt’s head with his fists, and pounded
it with a rock. This, however, did not kill Delahunt, so
Poyson took the bread knife and drove it through his ear.
Although the blade penetrated Delahunt’s skull and exited
through his nose, the wound was not fatal. Poyson thereafter
continued to slam Delahunt’s head against the floor until
Delahunt lost consciousness. According to the medical
examiner, Delahunt died of massive blunt force head trauma.
In all, the attack lasted about 45 minutes.
                       POYSON V . RYAN                         7

     After cleaning themselves up, Poyson and Anderson
prepared to kill Kagen and Wear. They first located Wear’s
.22 caliber rifle. Unable to find ammunition, Poyson
borrowed two rounds from a young girl who lived next door,
telling her that Delahunt was in the desert surrounded by
snakes and the bullets were needed to rescue him. Poyson
loaded the rifle and tested it for about five minutes to make
sure it would function properly. He then stashed it near a
shed. Later that evening, he cut the telephone line to the
trailer so that neither of the remaining victims could call for
help.

     After Kagen and Wear were asleep, Poyson and Anderson
went into their bedroom. Poyson first shot Kagen in the head,
killing her instantly. After quickly reloading the rifle, he shot
Wear in the mouth, shattering Wear’s upper right teeth. A
struggle ensued, during which Poyson repeatedly clubbed
Wear in the head with the rifle. The fracas eventually moved
outside. At some point, Anderson threw a cinder block at
Wear, hitting him in the back and knocking him to the
ground. While the victim was lying there, Poyson twice
kicked him in the head. He then picked up the cinder block
and threw it several times at Wear’s head. After Wear
stopped moving, Poyson took his wallet and the keys to
Wear’s truck. To conceal the body, Poyson covered it with
debris from the yard. Poyson, Anderson and Lane then took
the truck and traveled to Illinois, where they were
apprehended several days later.

B. Trial and Conviction

   A grand jury indicted Poyson on three counts of first
degree murder, one count of conspiracy to commit murder
8                     POYSON V . RYAN

and one count of armed robbery. The jury convicted on all
counts in March 1998, following a six-day trial.

C. Sentencing

    1. Mitigation Investigation

    Following the guilty verdicts, the state trial court
approved funds to hire a mitigation specialist to assist in
preparing for Poyson’s sentencing. Counsel retained
investigator Blair Abbott.

    In a June 1998 memorandum, Abbott informed counsel
that Poyson’s mother, Ruth Garcia (Garcia), used drugs
during the first trimester of her pregnancy and recommended
that counsel investigate the possibility that Poyson suffered
brain damage as a result. The memorandum advised counsel
that “one of the significant issues should be the hard core
drug abuse of both [of Poyson’s] parents, preconception and
in the first trimester of Ruth’s pregnancy.” Abbott wrote that
“Ruth Garcia’s heavy drug abuse in the pre pregnancy and
early on in the pregnancy undoubtedly caused severe damage
to her unborn child.”

     In September 1998, Abbott mailed trial counsel “Library
& Internet research regarding drug & alcohol fetal cell
damage; reflecting how these chemicals when taken in the
first trimester [a]ffect subsequent intelligence, conduct,
emotions, urges etc [sic] as the child grows into adulthood.”

    2. Presentence Investigation Report

   The probation office prepared a presentence investigation
report in July 1998. Poyson told the probation officer that he
                          POYSON V . RYAN                                9

had a bad childhood because he was abused by a series of
stepfathers, who subjected him to physical, mental and
emotional abuse. Poyson also said he suffered from
impulsive conduct disorder, which was diagnosed when he
was 13. Poyson would not answer any questions on his
substance abuse history or juvenile record.

       3. Presentencing Hearing

    In October 1998, the trial court held a one-day
presentencing hearing. Poyson’s trial counsel called three
witnesses to present mitigating evidence: his aunt, Laura
Salas, his mother, Ruth Garcia, and the mitigation
investigator, Blair Abbott. Counsel also introduced 56
exhibits. Poyson did not testify. The witnesses testified
about Poyson’s drug and alcohol abuse and the mental and
physical abuse inflicted on Poyson by his stepfather,
Guillermo Aguilar, and maternal grandmother, Mary Milner.
They also testified that Poyson’s stepfather, Sabas Garcia
(Sabas), committed suicide in 1988, and that Sabas’ death had
a devastating effect on Poyson. They further testified that
Garcia used drugs and alcohol during the first three months
of her pregnancy with Poyson.

       4. Poyson’s Sentencing Memorandum

   In early November 1998, Poyson filed a sentencing
memorandum urging the court to find three statutory and 25
nonstatutory mitigating circumstances.1 As relevant here,


   1
      At the time of Poyson’s sentencing, Arizona law required the
sentencing judge to impose a sentence of death if the court found one or
more aggravating circumstances and “no mitigating circumstances
sufficiently substantial to call for leniency.” Ariz. Rev. Stat. Ann. § 13-
10                        POYSON V . RYAN

Poyson argued that his history of drug and alcohol abuse,
troubled childhood and personality disorders constituted both
statutory and nonstatutory mitigating circumstances.

    Substance Abuse: Poyson argued that his substance abuse
was a statutory mitigating circumstance because it impaired
his capacity to appreciate the wrongfulness of his conduct or
conform his conduct to the requirements of law at the time of
the murders. See Ariz. Rev. Stat. Ann. § 13-703(G)(1)
(1998). In the alternative, he argued that, even if his
substance abuse was not causally related to the murders, it
constituted a nonstatutory mitigating circumstance. In
support of these arguments, Poyson emphasized his biological
parents’ use of drugs and alcohol at the time of his
conception, his mother’s use of drugs and alcohol during
pregnancy, an incident in which Poyson was involuntarily
intoxicated at the age of three or four, Poyson’s abuse of
alcohol beginning at age 13 and Poyson’s five-month
placement at WestCare, a residential treatment facility, for
substance abuse treatment in 1992, when he was 15. Poyson
also pointed to evidence that he used PCP two days before the
murders, used alcohol the night before the murders, used
marijuana the day of the murders and had suffered a PCP
flashback during Delahunt’s murder.



703(E) (1998). The law enumerated 10 aggravating circumstances, see id.
§ 13-703(F), and five statutory mitigating circumstances – including
diminished capacity, duress, minor participation and the defendant’s age,
see id. § 13-703(G). The sentencing court also was required to consider
any nonstatutory mitigating circumstances offered by the defendant – i.e.,
“any factors proffered by the defendant or the state which are relevant in
determining whether to impose a sentence less than death, including any
aspect of the defendant’s character, propensities or record and any of the
circumstances of the offense.” Id.
                       POYSON V . RYAN                         11

    Troubled Childhood: Poyson argued that his troubled
childhood was a statutory mitigating circumstance because it
affected his behavior at the time of the murders. In the
alternative, he argued that his troubled childhood constituted
a nonstatutory mitigating circumstance. Poyson emphasized
his mother’s use of drugs and alcohol during the first
trimester of pregnancy. He argued that alcohol and drug use
during pregnancy can cause brain damage and birth defects
and lead a child to engage in delinquent and criminal
behavior. He also attached to the sentencing memorandum
several scientific articles on fetal alcohol syndrome. The
memorandum pointed out that Poyson never knew his
biological father, lacked a stable home life, was physically
and mentally abused by several adults (including Aguilar and
Milner), was devastated by Sabas’ suicide and was sexually
abused and sodomized at a young age.2 Poyson emphasized
that his delinquent behavior and substance abuse began
shortly after the death of Sabas and the sexual assault.

    Mental Health Issues: The sentencing memorandum
argued that Poyson suffered from several personality
disorders, constituting a nonstatutory mitigating
circumstance. The memorandum pointed to a 1990
psychiatric evaluation by Dr. Bruce Guernsey. According to
the sentencing memorandum, Guernsey diagnosed Poyson
with severe “conduct disorder,” reported that Poyson
exhibited symptoms of antisocial behavior, “manic
depression” or “impulsive conduct disorder” and
recommended that Poyson be prescribed medication to
control his behavior. Poyson also pointed to a 1990 Juvenile
Predisposition Investigation by Nolan Barnum. Barnum too

   2
     Poyson presented evidence that he was sexually assaulted by a
neighbor on one occasion shortly after Sabas’ death.
12                    POYSON V . RYAN

recommended that Poyson be prescribed medication to
control his behavior. A 1993 psychological evaluation
performed by Jack Cordon and Ronald Jacques from the State
Youth Services Center in St. Anthony, Idaho, diagnosed
Poyson with “mild mood disturbance.” Dr. Celia A. Drake,
who Poyson’s counsel retained to perform a forensic
evaluation of Poyson, diagnosed “Adjustment Disorder with
depressive mood, mild intensity,” and “Anti-social
Personality Disorder.” Dr. Drake found Poyson’s overall
intellectual functioning to be “in the low average range.”

     5. Sentencing Hearing and Imposition of Sentence

    The trial court held a sentencing hearing and imposed
sentence in late November 1998.

    The court found that the state had proved, beyond a
reasonable doubt, three aggravating circumstances for the
murders of Delahunt and Wear: the murders were committed
in expectation of pecuniary gain, the murders were especially
cruel and multiple homicides committed during the same
offense. See Ariz. Rev. Stat. Ann. § 13-703(F)(5), (6), (8)
(1998). The court found two aggravating circumstances
applicable to Kagen’s murder: pecuniary gain and multiple
homicides. See id. § 13-703(F)(5), (8).

   The court found that Poyson failed to prove any statutory
mitigating factors. Poyson’s difficult childhood and mental
health issues were not statutory mitigating factors under § 13-
703(G)(1) because they did not significantly impair Poyson’s
capacity to appreciate the wrongfulness of his conduct or to
                         POYSON V . RYAN                              13

conform his conduct to the requirements of law.3 The court
explained:

             There has certainly been evidence that the
         defendant had gone through a turbulent life,
         perhaps had mental-health issues that would
         distinguish him from the typical person on the
         street.

             Listening to his description of how these
         murders were committed, based upon a
         description of somewhat a methodical
         carrying out of a plan, the Court sees
         absolutely nothing on the record, in this case,
         to suggest the applicability of this mitigating
         circumstance.

    Turning to nonstatutory mitigating factors, the court first
explained the three-step analysis it used to evaluate each
nonstatutory mitigating circumstance proffered by Poyson:
“[1] to analyze whether the defense has shown this fact by a
preponderance of evidence, and then if they have, [2] to
determine whether I would assign that any weight as a
mitigating factor, and of course, for any that . . . pass both of
those two tests, [3] I have to weigh them all along with the
other factors in the final [sentencing] determination in this
case.”



   3
      See Ariz. Rev. Stat. Ann. § 13-703(G)(1) (1998) (“Mitigating
circumstances [include] [t]he defendant’s capacity to appreciate the
wrongfulness of his conduct or to conform his conduct to the requirements
of law was significantly impaired, but not so impaired as to constitute a
defense to prosecution.”).
14                        POYSON V . RYAN

   Mental Health Issues: The court rejected Poyson’s
mental health issues as a nonstatutory mitigating factor at the
second step in the analysis. The court found that Poyson had
proven that he suffered from personality disorders, but gave
them no weight because they were not causally related to the
murders:

         [T]he defendant had some mental health and
         psychological issues. I think . . . the defense
         has established that there were certain . . .
         personality disorders that the defendant, in
         fact, may have been suffering from.

             The Court, however, does not find that
         they rise to the level of being a mitigating
         factor because I am unable to draw any
         connection whatsoever with such personality
         disorders and the commission of these
         offenses.4

   Troubled Childhood: The court similarly rejected
Poyson’s difficult childhood as a nonstatutory mitigating


  4
    T he court rejected evidence of Poyson’s low IQ for similar reasons.
At the first step in the analysis, the court found that “there is certain
evidence in this case that would support the proposition that the
defendant’s mental capacity may be diminished, at least compared to the
norm in the population, and that his I.Q. may be low, at least compared to
the norm in the population.” The court, however, gave this circumstance
no mitigating weight in light of planning and sophistication that went into
the crimes – “certain prep[ar]atory steps that were taken – admittedly, not
overly-sophisticated, but attempts were made to do certain things, to
disable warning systems to enable these murders to be committed and to
get away with the loot that was the purpose of the murders; specifically,
the vehicle.”
                          POYSON V . RYAN                             15

factor. At step one, the court found that the “defense has
shown that defendant suffered a dysfunctional childhood, that
he was subjected to physical and sexual abuse, and that he
was subjected to certain levels of mental abuse.” At step two,
however, the court gave these circumstances no mitigating
weight because they were not causally connected to the
murders: “The Court finds absolutely nothing in this case to
suggest that his latter conduct was a result of his childhood.”5

    Substance Abuse: Finally, the court rejected Poyson’s
history of substance abuse at both steps one and two in the
analysis: Poyson failed to establish a significant history of
drug or alcohol abuse and, even if he could do so, the court
would have given the evidence no weight because he failed
to establish a causal connection between the substance abuse
and the crimes. The court said:

         The argument is made that the defendant was
         subjected to alcohol abuse and drug abuse.
         Other than very vague allegations that he has
         used alcohol in the past or has used drugs in
         the past, other than a fairly vague assertion
         that he was subject to some sort of effect of
         drugs and/or alcohol at the time, that these
         offenses were committed, I really find very
         little to support the allegation that the
         defendant has a significant alcohol and/or


    5
      The court also found that “the defense has established, by a
preponderance of the evidence, that the defendant lost a parent figure and
was subjected to sexual abuse at a relatively young age.” The court
rejected this factor at step two, however, because it was “not convinced
that there is any connection between that abuse, that loss, and his
subsequent criminal behavior.”
16                    POYSON V . RYAN

        drug abuse, and again, going back to the
        methodical steps that were taken to murder
        three people to get a vehicle to get out of
        Golden Valley, it’s very difficult for me to
        conclude that the defendant’s ability to engage
        in goal-oriented behavior was, in any way,
        impaired at the time of the commission of
        these offenses.

   The court found only one nonstatutory mitigation factor
– Poyson’s cooperation with law enforcement. The court
concluded that this one mitigating factor was insufficiently
substantial to call for leniency and imposed a sentence of
death.

     6. Arizona Supreme Court Decision

    The Arizona Supreme Court affirmed Poyson’s
conviction and sentence on direct appeal. See State v.
Poyson, 7 P.3d 79 (Ariz. 2000). As required by Arizona law,
the court “independently review[ed] the trial court’s findings
of aggravation and mitigation and the propriety of the death
sentence.” Ariz. Rev. Stat. Ann. § 13-703.01(A) (2000).

    The court agreed with the trial court that Poyson’s drug
use was not a statutory mitigating circumstance under § 13-
703(G)(1). See Poyson, 7 P.3d at 88–89. In the court’s view,
there was “scant evidence that he was actually intoxicated on
the day of the murders.” Id. at 88. “Although Poyson
purportedly used both marijuana and PCP ‘on an as available
basis’ in days preceding these crimes, the only substance he
apparently used on the date in question was marijuana,” and
Poyson “reported smoking the marijuana at least six hours
before killing Delahunt and eleven hours before the murders
                      POYSON V . RYAN                        17

of Kagen and Wear.” Id. The evidence that Poyson
experienced a PCP flashback during the murder of Delahunt
was not credible, and even if the flashback occurred, it lasted
only a “few moments.” Id. at 88–89. Poyson was “not under
the influence of PCP at any other time.” Id. at 89. Poyson’s
claims of substantial impairment were also belied by his
deliberate actions, including concocting a ruse to obtain
bullets from a neighbor, testing the rifle to make sure it would
work properly when needed, cutting the telephone line and
concealing the crimes. See id.

    Substance Abuse: The court also agreed with the trial
court that Poyson’s substance abuse, mental health and
abusive childhood were not nonstatutory mitigating
circumstances. As to substance abuse, the court agreed with
the trial court that Poyson had failed at step one because the
evidence did not show a history of drug or alcohol abuse:

        The trial judge refused to accord any weight
        to the defendant’s substance abuse as a
        nonstatutory mitigating circumstance. It
        characterized the defendant’s claims that he
        had used drugs or alcohol in the past or was
        under the influence of drugs on the day of the
        murders as little more than “vague
        allegations.” As discussed above, we agree.

Id. at 90.

    Mental Health Issues: With respect to mental health
issues, the court agreed with the trial court that Poyson’s
personality disorders, although proven at step one, were
entitled to no weight at step two because they were not
causally connected to the murders:
18                   POYSON V . RYAN

       The trial court found that Poyson suffers from
       “certain personality disorders” but did not
       assign any weight to this factor. Dr. Celia
       Drake diagnosed the defendant with antisocial
       personality disorder, which she attributed to
       the “chaotic environment in which he was
       raised.” She found that there was, among
       other things, no “appropriate model for moral
       reasoning within the family setting” to which
       the defendant could look for guidance.
       However, we find no indication in the record
       that “the disorder controlled [his] conduct or
       impaired his mental capacity to such a degree
       that leniency is required.” State v. Brewer,
       170 Ariz. 486, 505, 826 P.2d 783, 802 (1992);
       see also [State v. Medina, 193 Ariz. 504, 517,
       975 P.2d 94, 107 (1999)] (holding that the
       defendant’s personality disorder “ha[d] little
       or no mitigating value” where the defendant’s
       desire to emulate his friends, not his mental
       disorder, was the cause of his criminal
       behavior). We therefore accord this factor no
       mitigating weight.

Id. at 90–91.

    Troubled Childhood: The court also agreed with the trial
court’s assessment of Poyson’s troubled childhood. The
court found that Poyson established an abusive childhood at
step one, but gave this consideration no weight at step two
because of the absence of a causal nexus:

       Defendant presented some evidence that as a
       youngster he was physically and mentally
                          POYSON V . RYAN                              19

         abused by several stepfathers and his maternal
         grandmother. He also self-reported one
         instance of sexual assault by a neighbor.
         Again, however, defendant did not show that
         his traumatic childhood somehow rendered
         him unable to control his conduct. Thus, the
         evidence is without mitigating value.

Id. at 91.

    The court found three aggravating factors (pecuniary gain,
murder committed in an especially cruel manner and multiple
homicides), one statutory mitigating factor (Poyson’s age)
and three nonstatutory mitigating factors (cooperation with
law enforcement, potential for rehabilitation and family
support). See id. at 90–91.6 The court concluded that the
mitigating evidence was not sufficiently substantial to call for
leniency and affirmed the sentence of death. See id. at 91–92;
Ariz. Rev. Stat. Ann. § 13-703.1(B) (2000).

D. State Postconviction Review

    The Arizona Superior Court denied Poyson’s petition for
postconviction relief in 2003. The court provided a reasoned
decision on Poyson’s claim of penalty phase ineffective
assistance of counsel (his third claim in this appeal) but not
on Poyson’s claims that the Arizona courts failed to consider
relevant mitigating evidence (his first and second claims on
appeal). In 2004, the Arizona Supreme Court summarily
denied Poyson’s petition for review.


 6
    The Arizona Supreme Court thus found three more mitigating factors
than the trial court found. The appellate court nonetheless agreed with the
trial court that a death sentence was warranted.
20                    POYSON V . RYAN

E. Federal District Court Proceedings

    Poyson filed a federal habeas petition in 2004. In 2010,
the district court denied the petition. The court rejected on
the merits Poyson’s claims that the Arizona courts failed to
consider mitigating evidence. The court concluded that
Poyson’s penalty phase ineffective assistance of counsel
claim was procedurally defaulted because it was
“fundamentally different than [the claim] presented in state
court.” Poyson timely appealed.

 II. JURISDICTION AND STANDARD OF REVIEW

    We have jurisdiction under 28 U.S.C. §§ 1291 and
2253(a). We review de novo the district court’s denial of
Poyson’s petition for habeas corpus, and we review the
district court’s findings of fact for clear error. See Brown v.
Ornoski, 503 F.3d 1006, 1010 (9th Cir. 2007). Dismissals
based on procedural default are reviewed de novo. See
Robinson v. Schriro, 595 F.3d 1086, 1099 (9th Cir. 2010).
We address Poyson’s three claims in turn.

                    III. DISCUSSION

A. Causal Nexus Test

    Poyson argues that the Arizona courts applied an
unconstitutional causal nexus test to mitigating evidence of
his mental health issues, traumatic childhood and substance
abuse history, in violation of his Eighth and Fourteenth
Amendment rights to an individualized sentencing. He
contends that the state courts improperly refused to consider
this evidence in mitigation because he failed to establish a
causal connection between the evidence and the murders. He
                      POYSON V . RYAN                        21

argues that the state courts’ actions violate his constitutional
rights as recognized in Tennard v. Dretke, 542 U.S. 274,
283–87 (2004), Smith v. Texas, 543 U.S. 37, 45 (2004) (per
curiam), and several earlier decisions. These decisions hold
that requiring a defendant to prove a nexus between
mitigating evidence and the crime is “a test we never
countenanced and now have unequivocally rejected.” Smith,
543 U.S. at 45.

    Because Poyson filed his federal habeas petition after
April 24, 1996, he must not only prove a violation of these
rights but also satisfy the Antiterrorism and Effective Death
Penalty Act of 1996 (AEDPA). See Fenenbock v. Dir. of
Corr. for Cal., 681 F.3d 968, 973 (9th Cir. 2012).

    Under AEDPA, we may not grant habeas relief with
respect to any claim adjudicated on the merits in state court
unless the state court’s decision was “contrary to, or involved
an unreasonable application of, clearly established Federal
law, as determined by the Supreme Court of the United
States,” or “based on an unreasonable determination of the
facts in light of the evidence presented in the State court
proceeding.” 28 U.S.C. § 2254(d). We review the last
reasoned state court decision addressing the claim, which for
Poyson’s causal nexus claim is the Arizona Supreme Court’s
decision affirming Poyson’s death sentence on direct appeal.
See Crittenden v. Ayers, 624 F.3d 943, 950 (9th Cir. 2010).
Poyson relies on AEDPA’s “contrary to” prong, arguing that
the Arizona Supreme Court’s decision in State v. Poyson,
7 P.3d 79 (Ariz. 2000), was contrary to Lockett v. Ohio,
438 U.S. 586 (1978), Eddings v. Oklahoma, 455 U.S. 104
(1982), and Penry v. Lynaugh, 492 U.S. 302 (1989),
abrogated on other grounds by Atkins v. Virginia, 536 U.S.
304 (2002).
22                    POYSON V . RYAN

     1. Exhaustion

    As a threshold matter, we agree with Poyson that he has
fully exhausted this claim. The state argues that in state court
Poyson raised a causal nexus claim with respect to only
mental health issues and his troubled childhood, not his
history of substance abuse. We disagree. Having reviewed
the record, we conclude that Poyson exhausted the claim with
respect to all three categories of mitigating evidence. See
Powell v. Lambert, 357 F.3d 871, 874 (9th Cir. 2004) (“A
petitioner has exhausted his federal claims when he has fully
and fairly presented them to the state courts.”).

     2. Whether the Arizona Supreme Court’s Decision Was
        Contrary to Clearly Established Federal Law

     Lockett, Eddings and Penry held that “a State could not,
consistent with the Eighth and Fourteenth Amendments,
prevent the sentencer from considering and giving effect to
evidence relevant to the defendant’s background or character
or to the circumstances of the offense that mitigate against
imposing the death penalty.” Penry, 492 U.S. at 318. “[I]t is
not enough simply to allow the defendant to present
mitigating evidence to the sentencer.” Id. at 319. “The
sentencer must also be able to consider and give effect to that
evidence in imposing sentence.” Id. “[T]he sentence imposed
at the penalty stage should reflect a reasoned moral response
to the defendant’s background, character, and crime.” Id.
(quoting California v. Brown, 479 U.S. 538, 545 (1987)
(O’Connor, J., concurring)) (internal quotation marks
omitted).

    Under these decisions, a state court may not treat
mitigating evidence of a defendant’s background or character
                      POYSON V . RYAN                      23

as “irrelevant or nonmitigating as a matter of law” merely
because it lacks a causal connection to the crime. Towery v.
Ryan, 673 F.3d 933, 946 (9th Cir. 2012) (per curiam). The
sentencer may, however, consider “causal nexus . . . as a
factor in determining the weight or significance of mitigating
evidence.” Lopez v. Ryan, 630 F.3d 1198, 1204 (9th Cir.
2011). “The . . . use of the nexus test in this manner is not
unconstitutional because state courts are free to assess the
weight to be given to particular mitigating evidence.” Schad
v. Ryan, 671 F.3d 708, 723 (9th Cir. 2011) (per curiam). As
the Court explained in Eddings:

       Just as the State may not by statute preclude
       the sentencer from considering any mitigating
       factor, neither may the sentencer refuse to
       consider, as a matter of law, any relevant
       mitigating evidence. . . . The sentencer, and
       the Court of Criminal Appeals on review, may
       determine the weight to be given relevant
       mitigating evidence. But they may not give it
       no weight by excluding such evidence from
       their consideration.

Eddings, 455 U.S. at 113–15.

    Consistent with these principles, we have granted habeas
relief when state courts have applied a causal nexus test as a
screening mechanism to deem evidence irrelevant or
nonmitigating as a matter of law. In Styers v. Schriro,
547 F.3d 1026 (9th Cir. 2008) (per curiam), we granted relief
where the state court held that a defendant’s post-traumatic
stress disorder could not constitute mitigation unless the
defendant could connect the condition to the crime. See id.
at 1035. In Williams v. Ryan, 623 F.3d 1258 (9th Cir. 2010),
24                    POYSON V . RYAN

we granted relief where the state court held that, “[w]ithout
a showing of some impairment at the time of the offense,
drug use cannot be a mitigating circumstance of any kind.”
Id. at 1270–71 (alteration in original) (quoting State v.
Williams, 904 P.2d 437, 453 (Ariz. 1995)) (internal quotation
marks omitted).

    In contrast, we have refused to find a constitutional
violation when the state court employed a causal nexus test as
a permissible weighing mechanism. See Towery, 673 F.3d at
945–46. We have also denied relief when the record contains
no indication that the state court employed a causal nexus test
at all. See Schad, 671 F.3d at 724 (denying relief where
“there is no indication that the state courts applied a nexus
test, either as a method of assessing the weight of the
mitigating evidence, or as an unconstitutional screening
mechanism to prevent consideration of any evidence”);
Lopez, 630 F.3d at 1203–04 (denying relief where the state
courts made no mention of a causal nexus test, because “there
is no reason to infer unconstitutional reasoning from judicial
silence”).

    Here, the record shows that the Arizona Supreme Court
applied a causal nexus test to Poyson’s evidence of mental
health issues and a difficult childhood, see Poyson, 7 P.3d at
90–91, but does not reveal whether the court considered the
absence of a causal nexus as a permissible weighing
mechanism, as in Towery, or as an unconstitutional screening
mechanism, as in Styers and Williams. This ambiguity
precludes us from granting habeas relief. We held in Schad
that, “[a]bsent a clear indication in the record that the state
court applied the wrong standard, we cannot assume the
courts violated Eddings’s constitutional mandates.” 671 F.3d
at 724. That principle governs here: we cannot assume the
                       POYSON V . RYAN                        25

state court applied the wrong standard. The Arizona Supreme
Court’s decision therefore was not contrary to clearly
established federal law under § 2254(d)(1).

    We reach the same conclusion with respect to the Arizona
Supreme Court’s evaluation of Poyson’s evidence of a history
of substance abuse. The state court rejected this evidence at
step one in its analysis, finding as a matter of fact that Poyson
had failed to establish a significant history of substance abuse
by a preponderance of the evidence. The record does not
indicate that the court considered this evidence at step two, or
that, if it did so, it employed an impermissible causal nexus
test in doing so. See Poyson, 7 P.3d at 90. The court’s
treatment of Poyson’s substance abuse evidence thus was
likewise not contrary to Lockett, Eddings and Penry.

    We recognize the possibility that the Arizona Supreme
Court applied an unconstitutional causal nexus test. The
record, however, contains no clear indication that the court
did so. We may not presume a constitutional violation from
an ambiguous record. We therefore hold that the district
court properly denied habeas relief on Poyson’s causal nexus
claim. See Schad, 671 F.3d at 724.

     The dissent contends that Schad’s presumption that state
courts follow constitutional requirements should not apply
here for three reasons. First, citing the Arizona Supreme
Court’s historical use of an unconstitutional causal nexus test
at the time of Poyson’s sentencing, the dissent argues that we
should presume error. Dissent 37–38. This argument would
be persuasive if the Arizona courts consistently applied an
unconstitutional causal nexus test during the relevant period.
That is not the case, however. As we recognized in Lopez,
26                    POYSON V . RYAN

       Our review of the case law confirms
       Arizona’s unsettled past with respect to this
       issue. Some cases decided prior to Tennard
       applied a causal nexus requirement in an
       impermissible manner. Other cases, however,
       properly looked to causal nexus only as a
       factor in determining the weight or
       significance of mitigating evidence.

630 F.3d at 1203–04 (footnote omitted); see also Towery,
673 F.3d at 946 (also recognizing that the Arizona Supreme
Court’s decisions have been inconsistent on this question).
Under these circumstances, the most we can say is that
Arizona’s troublesome history weakens the presumption that
the Arizona Supreme Court followed the law in Poyson’s
case; it does not flip the presumption altogether.

     Second, the dissent argues that the presumption that state
courts follow constitutional mandates applies only to a silent
record and not to the interpretation of a state court’s
language. Dissent 41–42. This argument overlooks the
Supreme Court’s decision in Woodford v. Visciotti, 537 U.S.
19 (2002). There, the state court applied an arguably
erroneous test for determining prejudice under Strickland v.
Washington, 466 U.S. 468 (1984). Some language in the
state court’s decision cited the test correctly, whereas other
language misstated the test. See Visciotti, 537 U.S. at 22–24.
We held that the state court had applied an erroneous test, but
the Supreme Court reversed, holding that our “readiness to
attribute error is inconsistent with the presumption that state
courts know and follow the law.” Id. at 24. After Visciotti,
therefore, we must consider the presumption that state courts
follow the law not only when we draw inferences from the
                      POYSON V . RYAN                        27

court’s silence but also when, as here, we construe a state
court’s ambiguous language.

    Third, quoting Justice O’Connor’s concurrence in
Eddings, the dissent argues that “the qualitatively different
nature of a death sentence requires reviewing courts ‘to
remove any legitimate basis for finding ambiguity concerning
the factors actually considered by the trial court.’” Dissent 42
(quoting Eddings, 455 U.S. at 119 (O’Connor, J.,
concurring)). A majority of the Court, however, has never
adopted Justice O’Connor’s suggestion that ambiguity alone
requires habeas relief. Unlike Eddings, moreover, this case
is governed by AEDPA, and AEDPA does not allow us to
presume from an ambiguous record that the state court
applied an unconstitutional standard. To the contrary, such
a “readiness to attribute error” would be flatly “incompatible
with § 2254(d)’s highly deferential standard for evaluating
state-court rulings, which demands that state-court decisions
be given the benefit of the doubt.” Visciotti, 537 U.S. at 24
(citation and internal quotation marks omitted); cf. Lopez v.
Schriro, 491 F.3d 1029, 1037 (9th Cir. 2007) (holding that
alleged ambiguity in the state court’s language was
insufficient “to overcome the presumption that the state court
knew and followed the law”).

    At bottom, the ambiguous record in this case is no
different from those in Schad and Lopez, two cases in which
we declined to grant habeas relief. In both of those cases, we
denied relief notwithstanding Arizona’s troublesome history
of applying an unconstitutional causal nexus test – and
notwithstanding the existence of an ambiguous record. Here
too, in the absence of a clear indication in the record that the
state court applied an unconstitutional standard, we see no
alternative but to affirm.
28                      POYSON V . RYAN

B. Failure to Consider Substance Abuse

    At sentencing, Poyson presented evidence of a history of
drug and alcohol abuse, but the state trial court and the state
supreme court declined to treat the evidence as a nonstatutory
mitigating factor. The trial court found that Poyson had
presented only “very vague allegations that he has used
alcohol . . . or . . . drugs in the past,” and found “very little to
support the allegation that the defendant has a significant
alcohol and/or drug abuse” history. The supreme court
agreed that Poyson’s claims to have “used drugs or alcohol in
the past” were “little more than ‘vague allegations.’” Poyson,
7 P.3d at 90.

   Poyson contends the state courts’ conclusions that he
provided only “vague allegations” of substance abuse were
unreasonable determinations of the facts under 28 U.S.C.
§ 2254(d)(2) and violated his constitutional rights under
Lockett, 438 U.S. at 605, Eddings, 455 U.S. at 112, and
Parker v. Dugger, 498 U.S. 308, 321 (1991). We disagree.

    Poyson’s claim – that “[b]ecause his death sentence is
based upon [an] unreasonable determination of facts, [he] is
entitled to habeas relief” – misunderstands the law. Even
assuming that the state courts’ determination that Poyson
provided only “vague allegations” of substance abuse was an
unreasonable determination of the facts under § 2254(d)(2),
an issue we need not reach, Poyson’s claim fails because he
cannot demonstrate that his constitutional rights were
violated. See Wilson v. Corcoran, 131 S. Ct. 13, 17 (2010)
(per curiam) (holding that while § 2254(d)(2) relieves a
federal court of AEDPA deference when the state court
makes an unreasonable determination of facts, it “does not
repeal the command of § 2254(a) that habeas relief may be
                      POYSON V . RYAN                        29

afforded to a state prisoner ‘only on the ground’ that his
custody violates federal law”); see also Frantz v. Hazey,
533 F.3d 724, 737 (9th Cir. 2008) (en banc) (holding that
AEDPA does not “require any particular methodology for
ordering the § 2254(d) and § 2254(a) determination[s]”). An
unreasonable determination of the facts would not, standing
alone, amount to a constitutional violation under Lockett,
Eddings or Parker.

    Lockett invalidated an Ohio death penalty statute that
precluded the sentencer from considering aspects of the
defendant’s character or record as a mitigating factor. See
438 U.S. at 604. Eddings held that a sentencer may not
refuse to consider, as a matter of law, any relevant mitigating
evidence. See 455 U.S. at 113–15. Here, the state courts
considered Poyson’s evidence of substance abuse, but found
it wanting as a matter of fact and that Poyson failed to prove
a history of substance abuse.           Thus, there was no
constitutional violation under Lockett and Eddings.

    Nor has Poyson shown a constitutional violation under
Parker.      There, the state supreme court reweighed
aggravating and mitigating circumstances before affirming a
death sentence. See Parker, 498 U.S. at 321–22. The court’s
reweighing, however, was premised on its erroneous
assumption that the state trial court had found that there were
no mitigating circumstances. See id. The Supreme Court
held that the state supreme court’s action deprived the
defendant of “meaningful appellate review,” and thus that the
sentencing violated the defendant’s right against “the
arbitrary or irrational imposition of the death penalty.” Id. at
321. In Poyson’s view, Parker stands for the broad
proposition that, “[w]hen a state court’s imposition of the
death penalty is based not on the characteristics of the
30                    POYSON V . RYAN

accused and the offense but instead on a misperception of the
record, the defendant is not being afforded the consideration
that the Constitution requires.” In Parker, however, the state
supreme court had misconstrued the state trial court’s
findings, something that did not occur here. Parker does not
hold that a state court’s erroneous factual finding in assessing
mitigation evidence necessarily amounts to a constitutional
violation. Rather, it suggests the opposite:

        This is not simply an error in assessing the
        mitigating evidence.       Had the Florida
        Supreme Court conducted its own
        examination of the trial and sentencing
        hearing records and concluded that there were
        no mitigating circumstances, a different
        question would be presented. Similarly, if the
        trial judge had found no mitigating
        circumstances and the Florida Supreme Court
        had relied on that finding, our review would
        be very different.

Id. at 322.

    In sum, we hold that Poyson is not entitled to habeas
relief because he has not shown a constitutional violation
under Lockett, Eddings or Parker. Because Poyson has raised
arguments under only Lockett, Eddings and Parker, we need
not decide whether, or under what circumstances, a state
court’s erroneous factfinding in assessing mitigating evidence
can itself rise to the level of a constitutional violation.
                       POYSON V . RYAN                         31

C. Penalty Phase Ineffective Assistance of Counsel

    In his federal habeas petition, Poyson argued that he
received ineffective assistance of counsel during the penalty
phase of his trial because his trial counsel failed to investigate
the possibility that he suffered from fetal alcohol spectrum
disorder (FASD). The district court ruled that Poyson failed
to present this claim to the state courts, and hence that the
claim was procedurally defaulted. Poyson challenges that
ruling on appeal. We review de novo. See Robinson,
595 F.3d at 1099.

    A state prisoner must normally exhaust available state
judicial remedies before a federal court will entertain his
petition for habeas corpus. See Picard v. Connor, 404 U.S.
270, 275 (1971); Weaver v. Thompson, 197 F.3d 359, 363–64
(9th Cir. 1999); 28 U.S.C. § 2254(b)(1)(A). This rule
“reflects a policy of federal-state comity, an accommodation
of our federal system designed to give the State an initial
opportunity to pass upon and correct alleged violations of its
prisoners’ federal rights.” Picard, 404 U.S. at 275 (citations
and internal quotation marks omitted). “A petitioner can
satisfy the exhaustion requirement by providing the highest
state court with a fair opportunity to consider each issue
before presenting it to the federal court.” Weaver, 197 F.3d
at 364.

    “[A] petitioner may provide further facts to support a
claim in federal district court, so long as those facts do not
‘fundamentally alter the legal claim already considered by the
state courts.’” Lopez v. Schriro, 491 F.3d 1029, 1040 (9th
Cir. 2007) (quoting Vasquez v. Hillery, 474 U.S. 254, 260
32                       POYSON V . RYAN

(1986)).7 “[T]his rule allows a petitioner who presented a
particular [ineffective assistance of counsel] claim, for
example that counsel was ineffective in presenting
humanizing testimony at sentencing, to develop additional
facts supporting that particular claim.” Moormann v. Schriro,
426 F.3d 1044, 1056 (9th Cir. 2005) (citing Weaver, 197 F.3d
at 364). “This does not mean, however, that a petitioner who
presented any ineffective assistance of counsel claim below
can later add unrelated alleged instances of counsel’s
ineffectiveness to his claim.” Id. (citing Carriger v. Lewis,
971 F.2d 329, 333 (9th Cir. 1992) (en banc)).

     1. State Proceedings

    In his state habeas petition, Poyson raised two ineffective
assistance of counsel claims relevant here. In the first claim,
Poyson alleged that trial counsel “was ineffective because he
failed to request the appointment of experts in the field of
mental health early in the case.” He alleged that the
investigation for both phases of the trial should have begun
“immediately” upon counsel’s appointment, including “the
immediate appointment of experts for both parts of the trial.”
Counsel’s failure “to immediately secure the appointment of
mental health experts . . . prejudiced” him in two ways. First,
it precluded him from presenting a defense of “diminished
capacity” with respect to the Delahunt murder during the guilt
phase of the trial. Second, “the failure of counsel to
immediately pursue mitigation caused the loss of mitigating
information” that could have been presented at sentencing.


 7
   As the Supreme Court has recently clarified, these factual allegations
must be based on the “record that was before the state court that
adjudicated the claim on the merits.” Cullen v. Pinholster, 131 S. Ct.
1388, 1398 (2011).
                      POYSON V . RYAN                       33

Poyson presented a report by a neuropsychologist retained
during the state habeas proceedings, Robert Briggs, Ph.D.
According to Poyson, Briggs’ report showed that Poyson
“was brain-damaged” at the time of the murders, but had
since “recovered, due to his long stay first in jail, then on
condemned row, without chemical or physical insult to his
brain.” In Poyson’s view, “the report leaves no doubt that
neurophyschological testing shows that he was impaired at
the time of the crime.” This mitigating evidence had been
“lost forever.”

     In the state petition’s second claim, Poyson alleged that
trial counsel failed to properly present mitigation and
psychological evidence because counsel “did nothing to show
the trial court how [his] abusive childhood caused, or directly
related to, [his] conduct during the murders.” He alleged that
trial counsel were deficient because they were “required to
make some attempt to correlate Mr. Poyson’s physically and
psychologically abusive background with his behavior,”
because “a connection between the two would be much more
powerful in mitigation than the abuse standing alone.”

   2. Federal Petition

     Poyson’s federal petition presented a substantially
different claim – counsel’s failure to investigate Poyson’s
possible fetal alcohol spectrum disorder. Poyson alleged that
trial counsel were ineffective because they “failed to make
any effort to investigate and develop” evidence that Poyson
suffered from FASD. He alleged that defense counsel “failed
to investigate the obvious possibility that [he] suffered from
FASD,” made “no effort” to “pursue this fertile area of
mitigation” and “ignored obvious evidence that [he] was
exposed to drugs and alcohol in utero.” Poyson further
34                    POYSON V . RYAN

alleged that he was prejudiced by counsel’s deficient
performance:

        Their failure to adequately investigate and
        substantiate [evidence that Petitioner was
        exposed to drugs and alcohol in utero]
        profoundly prejudiced Petitioner. Adequate
        explanation during the pre-sentence hearing of
        the effect of FASD on Petitioner’s brain
        would likely have convinced the trial court
        that Petitioner had a lesser degree of
        culpability.

     3. Analysis

    The district court concluded that the claim raised in the
federal petition had not been fairly presented to the Arizona
courts:

        This Court concludes that the claim asserted
        in the instant amended petition is
        fundamentally different than that presented in
        state court. Petitioner’s argument in support
        of [this claim] is based entirely on trial
        counsel’s alleged failure to investigate and
        develop mitigation evidence based on
        Petitioner’s in utero exposure to drugs and
        alcohol.     This version of Petitioner’s
        sentencing [ineffective assistance of counsel]
        claim has never been presented to the Arizona
        courts. While it is true that new factual
        allegations do not ordinarily render a claim
        unexhausted, a petitioner may not
        “fundamentally alter the legal claim already
                     POYSON V . RYAN                      35

       considered by the state courts.” Beaty v.
       Stewart, 303 F.3d 975, 989–90 ([9th Cir.]
       2002) (citing Vasquez, 474 U.S. at 260). To
       do so deprives the state court of “a meaningful
       opportunity to consider allegations of legal
       error without interference from the federal
       judiciary.” Vasquez, 474 U.S. at 257. Here,
       Petitioner is not simply proffering additional
       evidentiary support for a factual theory
       presented to the state court. Rather, he is
       alleging an entirely new theory of counsel
       ineffectiveness; one that has not previously
       been presented in state court.

    We agree. Poyson presented not only new facts in
support of a claim presented to the state court, but also a
fundamentally new theory of counsel’s ineffectiveness – one
that the Arizona courts lacked “a meaningful opportunity to
consider.” Vasquez, 474 U.S. at 257. The district court
therefore properly dismissed Poyson’s penalty phase
ineffective assistance of counsel claim as procedurally
defaulted.

   AFFIRMED.



THOMAS, Circuit Judge, concurring in part and dissenting
in part:

    The Arizona Supreme Court unconstitutionally excluded
mitigating evidence from its consideration because the
evidence was not causally related to the crimes. As a result,
Poyson was deprived of his right to an individualized capital
36                    POYSON V . RYAN

sentencing determination under the Eighth and Fourteenth
Amendments. Penry v. Lynaugh (Penry I), 492 U.S. 302, 317
(1989), abrogated on other grounds by Atkins v. Virginia,
536 U.S. 304 (2002); Eddings v. Oklahoma, 455 U.S. 104,
110–12 (1982); Lockett v. Ohio, 438 U.S. 586, 604–05
(1978). Because the majority’s contrary conclusion cannot be
reconciled with controlling Supreme Court precedent, I
respectfully dissent.

                              I

    “[I]n capital cases the fundamental respect for humanity
underlying the Eighth Amendment . . . requires consideration
of the character and record of the individual offender and the
circumstances of the particular offense as a constitutionally
indispensable part of the process of inflicting the penalty of
death.” Lockett, 438 U.S. at 604 (alteration in original)
(quoting Woodson v. North Carolina, 428 U.S. 280, 304
(1976)). Accordingly, the Supreme Court has held since
1978 that a defendant facing a capital sentence must have the
opportunity to present all relevant evidence in mitigation.
See id. at 604–05. Merely admitting the evidence at the
penalty phase does not satisfy the constitutional mandate.
Rather, to ensure that a sentence of death reflects “a reasoned
moral response to a defendant’s background, character, and
crime,” Penry I, 492 U.S. at 328 (emphasis in original)
(quoting Franklin v. Lynaugh, 487 U.S. 164, 184 (1988)
(O’Connor, J., concurring in the judgment)), the procedure
for evaluating mitigating evidence must ensure that the
sentencer is “able to consider and give effect to that evidence
in imposing sentence,” id. at 319 (emphasis added) (citing
Hitchcock v. Dugger, 481 U.S. 393 (1987)); see also Eddings,
455 U.S. at 113–14. A sentencer “give[s] effect to”
mitigating evidence by weighing all such admissible evidence
                      POYSON V . RYAN                       37

against any aggravating circumstances proven by the state.
See, e.g., Eddings, 455 U.S. at 114–15; Towery v. Ryan,
673 F.3d 933, 944–45 (9th Cir. 2012). Only by viewing all
sentencing evidence in context can a court render the
individualized determination of moral culpability that the
Constitution requires. See Lambright v. Schriro, 490 F.3d
1103, 1115 (9th Cir. 2007) (per curiam).

    A court violates the constitutional command by
categorically screening out certain mitigating evidence as a
matter of law, before it may be weighed in combination with
all other relevant sentencing evidence. Tennard v. Dretke,
542 U.S. 274, 284–86 (2004); Eddings, 455 U.S. at 113–14
(holding that the sentencer may not “refuse to consider, as a
matter of law, any relevant mitigating evidence”) (emphasis
in original). Relevance is the only prerequisite to full
consideration of mitigating evidence. See Tennard, 542 U.S.
at 284–85. While the state court may assign a relative weight
to each item of admissible mitigating evidence, Towery,
673 F.3d at 944, it cannot impose any additional criteria, such
as a causal nexus requirement, to screen such evidence from
the sentencer’s ultimate view of the defendant.

    At the time it decided this case, the Arizona Supreme
Court applied a causal nexus test similar to the one the U.S.
Supreme Court held unconstitutional in Tennard. See, e.g.,
State v. Sansing, 77 P.3d 30, 37 (Ariz. 2003) (“Mere evidence
of drug ingestion or intoxication, however, is insufficient to
establish statutory mitigation. The defendant must also prove
a causal nexus between his drug use and the offense.”)
(footnote omitted); State v. Cañez, 42 P.3d 564, 594 (Ariz.
2002) (en banc) (citation omitted) (“[A] causal nexus between
the intoxication and the offense is required to establish
non-statutory impairment mitigation”); State v. Kayer,
38                    POYSON V . RYAN

984 P.2d 31, 45 (Ariz. 1999) (en banc) (“A defendant must
show a causal link between the alcohol abuse, substance
abuse, or mental illness and the crime itself” for such
evidence to be considered a mitigating factor); State v.
Clabourne, 983 P.2d 748, 756 (Ariz. 1999) (en banc)
(defendant’s difficult childhood not a mitigating factor
because “he has failed to link his family background to his
murderous conduct or to otherwise show how it affected his
behavior”); State v. Djerf, 959 P.2d 1274, 1289 (Ariz. 1998)
(en banc) (defendant’s experience of childhood abuse cannot
be considered as a mitigating factor unless there is a causal
connection between the abuse and the crime); State v. Jones,
937 P.2d 310, 322 (Ariz. 1997) (defendant did not establish
impaired capacity as either a statutory or non-statutory
mitigating factor because “no testimony establishes, either
because of his use of drugs or because he was coming down
off of the drugs, that defendant could not appreciate the
wrongfulness of his conduct or conform his conduct to the
law”); State v. Wallace, 773 P.2d 983, 986 (Ariz. 1989) (en
banc) (“A difficult family background, in and of itself, is not
a mitigating circumstance.”).

    Arizona’s causal nexus test not only violated Eddings, but
a long line of Supreme Court cases holding that all relevant
mitigating evidence must be considered in capital sentencing.
These cases establish that evidence of a defendant’s
background and character, including childhood trauma or
mental health problems, is relevant in mitigation even if it
does nothing to explain why the defendant committed the
crime of conviction. See Penry I, 492 U.S. at 322–23;
Lockett, 438 U.S. at 604. See also Lambright, 490 F.3d at
1115.     Such evidence may reasonably diminish the
defendant’s moral culpability, see Penry I, 492 U.S. at
322–23, and “might cause a sentencer to determine that a life
                      POYSON V . RYAN                        39

sentence, rather than death at the hands of the state, is the
appropriate punishment for the particular defendant,”
Lambright, 490 F.3d at 1115. Placing such evidence beyond
the sentencer’s effective reach is “simply unacceptable in any
capital proceeding,” id. (citing Lockett, 438 U.S. at 605),
because it deprives the sentencer of the complete,
multifaceted rendering of the defendant that must be the basis
for capital sentencing.

    Arizona’s unconstitutional causal nexus test remained in
force until Tennard, and it was in use when the Arizona
Supreme Court considered Poyson’s appeal.

                              II

    In reviewing pre-Tennard Arizona capital cases, we do
not presume that the Arizona Supreme Court
unconstitutionally refused to consider relevant mitigating
evidence in its re-weighing of aggravating and mitigating
factors. Rather, we examine the record to determine whether
the Arizona Supreme Court applied an unconstitutional causal
nexus test to screen mitigating evidence from consideration
in a particular case. In Schad v. Ryan, we affirmed the denial
of habeas relief when the record contained “no indication that
the state courts applied a nexus test, either as a method of
assessing the weight of the mitigating evidence, or as an
unconstitutional screening mechanism . . . .” 671 F.3d 708,
724 (9th Cir. 2009) (per curiam). In doing so, Schad was
consistent with the Supreme Court’s instruction that
“[f]ederal courts are not free to presume that a state court did
not comply with constitutional dictates on the basis of
nothing more than a lack of citation.” Bell v. Cone, 543 U.S.
447, 455 (2005) (citations omitted).
40                     POYSON V . RYAN

    Similarly, in Towery, we rejected the defendant’s claim
that the Arizona Supreme Court unconstitutionally screened
mitigating evidence that lacked a causal nexus to the crime.
673 F.3d at 944. We stressed that the state supreme court had
articulated the proper standard for considering mitigating
evidence. See id. In independently reviewing Towery’s
mitigating evidence, the state court recognized that, “[h]aving
considered family background during the penalty phase, the
sentencer must give the evidence such weight that the
sentence reflects a ‘reasoned moral response’ to the
evidence.” Id. (alteration in original) (quoting State v.
Towery (Towery I), 920 P.2d 290, 311 (Ariz. 1996)). In light
of the whole record, this statement demonstrated the Arizona
Supreme Court’s awareness that it must weigh all relevant
mitigating evidence against the aggravating circumstances,
even if it ultimately assigned relatively little weight to that
mitigating evidence which lacked a strong causal link to the
crime. See id. at 944–45.

    In contrast, in Styers v. Schriro, 547 F.3d 1026 (9th Cir.
2008), we looked beyond the Arizona Supreme Court’s
characterization of its own reasoning where the form of its
analysis evidenced unconstitutional screening. See id. at
1035 (“In conducting its independent review of the propriety
of Styers’ death sentence, the Arizona Supreme Court stated
that it had ‘considered all of the proffered mitigation’. . .
However, its analysis prior to this statement indicates
otherwise.”) (internal citation omitted). In that case, the state
court recognized that Styers’ evidence of post-traumatic
stress disorder “could . . . in an appropriate case, constitute
mitigation.” Id. (quoting State v. Styers, 865 P.2d 765, 777
(Ariz. 1993)). But it ultimately rejected Styers’ evidence for
lack of a causal nexus to the crime, noting that “two doctors
who examined defendant could not connect defendant’s
                      POYSON V . RYAN                       41

condition to his behavior at the time of the conspiracy and the
murder.” Id. (quoting State v. Styers, 865 P.2d at 777).
Though the state court claimed that it “considered” all
mitigating evidence, its analysis showed that it impermissibly
screened Styers’ mitigating mental health evidence solely
because it lacked a causal nexus to the crime. Declining to
elevate form over substance, we granted the writ upon
concluding that “the Arizona Supreme court appears to have
imposed a test directly contrary to the constitutional
requirement that all relevant mitigating evidence be
considered by the sentencing body.” Id. (emphasis added)
(citing Smith v. Texas, 543 U.S. 37, 45 (2004)).

    Recently, in Lopez v. Ryan, 630 F.3d 1198 (9th Cir.
2011), we declined to presume from Arizona case law alone
that “a tacit causation rule underpinned the state court’s
decision” in the case at hand. Id. at 1203. Rather than
“infer[ring] unconstitutional reasoning from judicial silence,”
Lopez instructs that we should “look to what the record
actually says.” Id. at 1204.

    The import of all these cases is that we should not
presume any constitutional error from a silent record, nor
should we accept without further examination a state court’s
characterizations of its own reasoning. Rather, we should
look to the substance of the record itself to determine whether
the state court unconstitutionally excluded relevant mitigating
evidence from consideration at sentencing.

    The majority appears to treat the statement in Schad that
relief should be denied “[a]bsent a clear indication in the
record that the state court applied the wrong standard” to
create a new, more stringent test for determining whether a
state court applied an unconstitutional causal nexus analysis.
42                         POYSON V . RYAN

671 F.3d at 724. The majority then applies this “test” to
resolve purported ambiguities in the record in the state’s
favor.

    However, in stating that we should identify “a clear
indication in the record” that the state court violated Tennard
before granting habeas relief, the Schad panel was merely
explaining Bell’s rule against presuming error from a silent
record. No Supreme Court case imposes a “clear indication”
test, nor does any case impose a rule that we must resolve
ambiguities against the petitioner. To the contrary, as Justice
O’Connor wrote in her Eddings concurrence, the qualitatively
different nature of a death sentence requires reviewing courts
“to remove any legitimate basis for finding ambiguity
concerning the factors actually considered by the trial court.”
455 U.S. at 119 (O’Connor, J., concurring). In short, if there
is any legitimate reason to believe that a court has excluded
mitigating evidence from consideration, we should grant
habeas relief so that a proper weighing of aggravating and
mitigating factors can occur. The appropriate approach, taken
in our more recent cases, is simply to evaluate “what the
record actually says.” Lopez, 630 F.3d at 1204 (citing Schad,
606 F.3d at 1046–47).1


  1
    Woodford v. Visciotti, 537 U.S. 19 (2002) (per curiam), is not to the
contrary. There, the Supreme Court simply rejected our reading of the
state court’s opinion; it did not instruct us to deny habeas relief whenever
the state court fails to provide a “clear indication” of constitutional error.
See id. at 24. While acknowledging that certain language in the state
court’s opinion could be read as misstating the Strickland standard, the
Woodford Court faulted us for rejecting other, stronger evidence in the
opinion indicating that the state court applied the correct standard. See id.
If anything, Woodford supports a close reading of state court decisions on
habeas review to determine whether they contravene or unreasonably
apply federal law. See id. at 23–24. As Woodford itself demonstrates, this
                            POYSON V . RYAN                                 43

                                      III

    Unlike the majority, I do not find the Arizona Supreme
Court’s opinion ambiguous in communicating its use of an
unconstitutional causal nexus test to screen Poyson’s
mitigating evidence of mental health problems and childhood
abuse.2 When we examine “what the record actually says” in
this case, the constitutional error is readily apparent.

    Like the sentencing court, the Arizona Supreme Court
accepted, as a factual matter, Poyson’s evidence of mental
health problems. See State v. Poyson, 7 P.3d 79, 90 (Ariz.
2000) (discussing expert testimony regarding Poyson’s
antisocial personality disorder). However, it “accord[ed] this
factor no mitigating weight” because it found “no indication
in the record that ‘the disorder controlled [his] conduct or
impaired his mental capacity to such a degree that leniency is
required.’” Id. at 90–91 (alteration in original) (quoting State
v. Brewer, 826 P.2d 783, 802 (Ariz. 1992)). Though the court
used the language of “weighing,” it plainly excluded the
evidence of Poyson’s antisocial personality disorder from its
final analysis of mitigating and aggravating circumstances,


approach does not offend “the presumption that state courts know and
follow the law.” Id. at 24 (citations omitted). Moreover, to the extent the
majority finds the Arizona Supreme Court’s opinion in this case
ambiguous on the causal nexus issue, Woodford is of little help, as it
simply does not address the analysis of an ambiguous state court decision
on habeas review. See id. at 23 (asserting that the state court opinion at
issue “painstakingly describes the [correct] Strickland standard”).

  2
     I agree with the majority that the Arizona Supreme Court did not
violate Eddings in rejecting Poyson’s evidence of substance abuse as a
mitigating factor, as it found that he failed to establish a significant history
of substance abuse as a matter of fact.
44                        POYSON V . RYAN

solely because it lacked a causal nexus to the crime. See id.
at 91 (listing only Poyson’s “cooperation with law
enforcement, age, potential for rehabilitation, and family
support” as mitigating evidence in the case, and finding that
evidence “not sufficiently substantial to call for leniency”).

    The court’s discussion of Poyson’s abusive childhood
more clearly reveals its use of a causal nexus screening
analysis. The court summarily recounted Poyson’s evidence
of physical, emotional, and sexual abuse as a child. See id.
However, because Poyson “did not show that his traumatic
childhood somehow rendered him unable to control his
conduct,” the court found the evidence “without mitigating
value.” Id. As a result, the Arizona Supreme Court omitted
the evidence of Poyson’s abusive childhood from its final
tally of mitigating circumstances. See id.

   As in Styers, this analysis demonstrates that the Arizona
Supreme Court, like the sentencing court below,3 screened


 3
   Though we review the Arizona Supreme Court’s opinion in this case,
the sentencing court’s analysis is relevant to the extent that the state
supreme court generally adopted its reasoning. W ithout a doubt, the
sentencing court’s discussion of Poyson’s proffered mitigating evidence
lends greater force to his Penry claim. For example, the sentencing court
accepted that Poyson suffers from personality disorders, yet the sentencing
judge concluded that this evidence did not “rise to the level of being a
mitigating factor because I am unable to draw any connection whatsoever
with such personality disorders and the commission of these offenses.” It
is unclear what the sentencing judge meant in saying that Poyson’s
personality disorders did not “rise to the level of being a mitigating
factor.” To the extent that the court excluded the evidence on the ground
that Poyson’s mental health problems were not sufficiently severe, it erred.
Evidence of mental health problems is relevant in mitigation, and a
defendant need not show that such problems rise to a specified level of
severity to establish their relevance. See Tennard, 542 U.S. at 284–85.
                         POYSON V . RYAN                              45

Poyson’s evidence of childhood abuse and mental health
problems from its final balancing of aggravating and
mitigating factors because that evidence lacked a causal
nexus to the crime. And like the panel that granted the writ
in Styers, we are not bound to accept a state court’s
characterization of its own analysis when its reasoning
reveals a deprivation of constitutional rights in violation of
clearly established law. This is particularly true when the
result of the state court’s error is to deprive a human being of
his life.

    The Eighth and Fourteenth Amendments prohibit state
courts from screening mitigating evidence from full
consideration based on a lack of causal nexus to the crime of
conviction. In reviewing Poyson’s sentence, however, the
Arizona Supreme Court applied a formula that automatically
assigned a “weight” or “value” of zero to all mitigating
evidence that lacked a causal nexus to the crime. Most
significantly, this total devaluation of Poyson’s mitigating
evidence occurred logically prior to the state court’s
balancing of aggravating and mitigating circumstances. See
State v. Poyson, 7 P.3d at 90–91. As such, the Arizona
Supreme Court failed to “consider all relevant mitigating
evidence and weigh it against the evidence of the aggravating
circumstances,” Eddings, 455 U.S. at 117 (emphasis added),
which prevented Poyson from presenting the totality of his
individualized circumstances to the court exercising authority
to condemn him to death. The “consideration” of Poyson’s
mitigating evidence was without meaning where the court
discarded that evidence before the critical stage of its


W hat is clear from this statement is that the sentencing court rejected
Poyson’s personality disorders as mitigating evidence because of the lack
of causal connection between those disorders and the murders at issue.
46                      POYSON V . RYAN

analysis—the final balancing of mitigating and aggravating
circumstances that determined his sentence. To label the
process “weighing” does not make it so; screening by any
other name is still screening.

    The Arizona Supreme Court did not consider mitigating
evidence offered by Poyson because it lacked a causal nexus
to the crime. In doing so, it committed Eddings error.
Remand is required.

     I respectfully dissent, in part.
