               FOR PUBLICATION

  UNITED STATES COURT OF APPEALS
       FOR THE NINTH CIRCUIT


GERALD ROSS PIZZUTO, JR.,               No. 16-36082
             Petitioner-Appellant,
                                          D.C. No.
                v.                     1:05-cv-00516-
                                            BLW
KEITH YORDY, Warden, Idaho
Maximum Security Institution,           ORDER AND
             Respondent-Appellee.        AMENDED
                                          OPINION


     Appeal from the United States District Court
               for the District of Idaho
   B. Lynn Winmill, Chief District Judge, Presiding

      Argued and Submitted December 11, 2018
              San Francisco, California

              Filed August 14, 2019
            Amended December 31, 2019

     Before: Raymond C. Fisher, Ronald M. Gould
      and Johnnie B. Rawlinson, Circuit Judges.

                 Per Curiam Opinion
2                        PIZZUTO V. YORDY

                            SUMMARY*


                Habeas Corpus /Death Penalty

   The panel affirmed the district court’s denial of Gerald
Ross Pizzuto, Jr.’s successive habeas corpus petition in which
Pizzuto challenged, based on Atkins v. Virginia, 536 U.S. 304
(2002), the Idaho Supreme Court’s 2008 decision that his
execution is not barred under an Idaho law prohibiting the
execution of intellectually disabled offenders.

    Applying 28 U.S.C. § 2254(d)(1), the panel held that the
record does not establish that the Idaho Supreme Court’s
decision was contrary to or involved an unreasonable
application of United States Supreme Court precedent. The
panel wrote that although the state court’s decision was
contrary to clinical standards in place at the time, it was not
obvious at that time that strict adherence to the clinical
standards was required. The panel also wrote that although
the state court’s requirement of an IQ of 70 or below is
contrary to Hall v. Florida, 572 U.S. 701 (2014); Brumfield
v. Cain, 135 S. Ct. 2269 (2015); and Moore v. Texas, 137
S. Ct. 1039 (2017), these decisions all postdated the state
court’s decision, and it was not obvious under Atkins alone
that, for Eighth Amendment purposes, an individual with an
IQ test score between 70 and 75 or lower may show
intellectual disability by presenting additional evidence
regarding difficulties in adaptive functioning.




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

    Applying 28 U.S.C. § 2254(d)(2), the panel held that the
record does not establish that the Idaho Supreme Court’s
decision was based on an unreasonable determination of the
facts in light of the evidence presented in the state court
proceeding. The panel rejected Pizzuto’s contention that the
state court’s factual determinations are unreasonable merely
because the state court did not apply the clinical definitions
of intellectual disability. The panel rejected Pizzuto’s
contention that the state court unreasonably failed to consider
his school records as evidence of subaverage intellectual
functioning. The panel rejected Pizzuto’s argument that the
state court unreasonably determined that his IQ could have
declined in adulthood due to drug abuse and epilepsy.
Regarding Pizzuto’s argument that the state court’s denial of
an evidentiary hearing was based on an unreasonable
determination of the facts, the panel wrote that the Idaho
Supreme Court never addressed the question of whether
Pizzuto raised a reasonable doubt regarding his intellectual
capacity, and that the Idaho Supreme Court’s failure to apply
a “reasonable doubt” standard was not contrary to or an
unreasonable application of Atkins. The panel wrote that
under the circumstances, the denial of an evidentiary hearing
did not render the state court’s factfinding process
unreasonable under § 2254(d)(2)’s highly deferential
standard.

    Because 28 U.S.C. § 2254(d) is not satisfied, the panel
held that the district court properly denied habeas relief. The
panel did not need to address Pizzuto’s remaining appellate
arguments or review his Atkins claim de novo. Accordingly,
the panel did not address whether Pizzuto is intellectually
disabled or whether his execution would violate the Eighth
Amendment. The panel wrote that its decision does not
4                   PIZZUTO V. YORDY

preclude the Idaho courts from reconsidering those questions
in light of intervening events.


                       COUNSEL

Joan M. Fisher (argued), Assistant Federal Defender; Heather
E. Williams, Federal Defender; Office of the Federal Public
Defender, Sacramento, California; Bruce D. Livingston and
Jonah Horwitz, Assistant Federal Public Defenders, Federal
Defenders of Idaho, Capital Habeas Unit, Boise, Idaho; for
Petitioner-Appellant.

L. LaMont Anderson (argued), Chief, Capital Litigation Unit;
Lawrence G. Wasden, Attorney General; Criminal Law
Division, Office of the Attorney General, Boise, Idaho; for
Respondent-Appellee.


                         ORDER

    The panel has voted to deny the petition for panel
rehearing. Judge Gould and Judge Rawlinson have voted to
deny the petition for rehearing en banc and Judge Fisher has
so recommended.

    The full court has been advised of the petition for
rehearing en banc and no judge has requested a vote on
whether to rehear the matter en banc. Fed. R. App. P. 35.

    The petition for panel rehearing and the petition for
rehearing en banc, filed November 27, 2019 (Dkt. 71), are
denied.
                         PIZZUTO V. YORDY                               5

   The opinion filed August 14, 2019, and reported at 933
F.3d 1166, is amended. An amended opinion is filed
concurrently with this order.

    No further petitions for rehearing may be filed.


                              OPINION

PER CURIAM:

    Gerald Ross Pizzuto, Jr., appeals the district court’s denial
of his successive petition for a writ of habeas corpus, in
which he sought relief based on the United States Supreme
Court’s decision in Atkins v. Virginia, 536 U.S. 304 (2002).
In Atkins, the Supreme Court held that the Eighth
Amendment prohibits the execution of intellectually disabled
persons.1 In response to Atkins, Idaho enacted a law
prohibiting the execution of intellectually disabled offenders.
See Idaho Code § 19-2515A. Pizzuto challenges the Idaho
Supreme Court’s decision that his execution is not barred
under that state law. See Pizzuto v. State (Pizzuto I), 202 P.3d
642 (Idaho 2008). We have jurisdiction under 28 U.S.C.
§§ 1291 and 2253, and we affirm the district court’s denial of
Pizzuto’s petition. Because the record does not establish that
the state court’s adjudication of Pizzuto’s Atkins 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,” or
“was based on an unreasonable determination of the facts in

    1
       We use the current clinical terms, intellectually disabled and
intellectual disability, except when quoting from sources using the former
terms, mentally retarded and mental retardation.
6                        PIZZUTO V. YORDY

light of the evidence presented in the State court proceeding,”
habeas relief may not be granted. See 28 U.S.C. § 2254(d).
Because habeas relief is barred under § 2254(d), we do not
address whether Pizzuto is intellectually disabled, nor
whether his execution would violate the Eighth Amendment.

                         BACKGROUND

   In 1986, a state trial court judge sentenced Pizzuto to
death for the murders of Berta Herndon and her nephew Del
Herndon. See Pizzuto I, 202 P.3d at 645. The Idaho Supreme
Court summarized the murders as follows:

           Pizzuto approached [the Herndons] with a .22
           caliber rifle as they arrived at their mountain
           cabin and made them enter the cabin. While
           inside, he tied the Her[n]dons’ wrists behind
           their backs and bound their legs in order to
           steal their money. Some time later, he
           bludgeoned Berta Herndon to death with
           hammer blows to her head and killed Del
           Herndon by bludgeoning him in the head with
           a hammer and shooting him between the eyes.
           Pizzuto murdered the Her[n]dons just for the
           sake of killing and subsequently joked and
           bragged about the killings to his associates.

Id.2


       2
     The Idaho Supreme Court’s 2008 decision attributes Del Herndon’s
shooting to Pizzuto. See Pizzuto I, 202 P.3d at 645. The Idaho Supreme
Court’s 1991 decision, by contrast, attributes the shooting to James Rice,
one of Pizzuto’s accomplices. See State v. Pizzuto, 810 P.2d 680, 687
(Idaho 1991), overruled on other grounds by State v. Card, 825 P.2d 1081
                         PIZZUTO V. YORDY                                7

    Sixteen years later, the Supreme Court decided Atkins,
holding that executions of intellectually disabled persons
constitute “cruel and unusual punishments” prohibited by the
Eighth Amendment to the United States Constitution. See
U.S. Const. amend. VIII. Citing “powerful evidence that
today our society views mentally retarded offenders as
categorically less culpable than the average criminal,” the
Court concluded that “a national consensus has developed
against” such executions. Atkins, 536 U.S. at 316.

    The Court, however, did not adopt any single definition
of intellectual disability. It noted that states’ “statutory
definitions of mental retardation [we]re not identical, but
generally conform[ed] to the clinical definitions set forth” by
the American Association on Mental Retardation (AAMR)
and the American Psychiatric Association. See id. at 317
n.22. At the time, the AAMR – now known as the American
Association on Intellectual and Developmental Disabilities
(AAIDD) – defined intellectual disability as follows:

         Mental retardation refers to substantial
         limitations in present functioning. It is
         characterized by significantly subaverage
         intellectual functioning, existing concurrently
         with related limitations in two or more of the
         following applicable adaptive skill areas:
         communication, self-care, home living, social
         skills, community use, self-direction, health
         and safety, functional academics, leisure, and


(Idaho 1991). In his petition for rehearing, Pizzuto contends that the 1991
decision is factually accurate and the 2008 decision is not, and we have no
reason to question Pizzuto’s contention. The question is immaterial to our
analysis.
8                     PIZZUTO V. YORDY

        work. Mental retardation manifests before age
        18.

Id. at 308 n.3 (quoting AAMR, Mental Retardation:
Definition, Classification, and Systems of Supports 5 (9th ed.
1992)). The American Psychiatric Association’s definition
was similar:

        The essential feature of Mental Retardation is
        significantly subaverage general intellectual
        functioning (Criterion A) that is accompanied
        by significant limitations in adaptive
        functioning in at least two of the following
        skill areas: communication, self-care, home
        living, social/interpersonal skills, use of
        community resources, self-direction,
        functional academic skills, work, leisure,
        health, and safety (Criterion B). The onset
        must occur before age 18 years (Criterion C).
        Mental Retardation has many different
        etiologies and may be seen as a final common
        pathway of various pathological processes
        that affect the functioning of the central
        nervous system.

Id. (quoting American Psychiatric Association, Diagnostic
and Statistical Manual of Mental Disorders 41 (4th ed. 2000)
(DSM-IV)). The Court noted that “an IQ between 70 and 75
or lower . . . is typically considered the cutoff IQ score for the
intellectual function prong of the mental retardation
definition,” id. at 309 n.5, and that “‘[m]ild’ mental
retardation is typically used to describe people with an IQ
level of 50–55 to approximately 70,” id. at 308 n.3 (quoting
DSM-IV at 42–43).
                      PIZZUTO V. YORDY                      9

    Atkins, however, did not expressly adopt these clinical
definitions of intellectual disability. The Court instead left
that question to the states:

        To the extent there is serious disagreement
        about the execution of mentally retarded
        offenders, it is in determining which offenders
        are in fact retarded. In this case, for instance,
        the Commonwealth of Virginia disputes that
        Atkins suffers from mental retardation. Not
        all people who claim to be mentally retarded
        will be so impaired as to fall within the range
        of mentally retarded offenders about whom
        there is a national consensus. As was our
        approach in Ford v. Wainwright, 477 U.S. 399
        (1986), with regard to insanity, “we leave to
        the State[s] the task of developing appropriate
        ways to enforce the constitutional restriction
        upon [their] execution of sentences.” Id.,
        at 405, 416–417.

Id. at 317 (alterations in original).

    Shortly after the Atkins decision, Idaho adopted a statute
prohibiting imposition of the death penalty for intellectually
disabled offenders. See 2003 Idaho Sess. Laws 399 (codified
at Idaho Code § 19-2515A(3)). The statute defines
intellectual disability as follows:

        (a) “Mentally retarded” means significantly
        subaverage general intellectual functioning
        that is accompanied by significant limitations
        in adaptive functioning in at least two (2) of
        the following skill areas: communication,
10                   PIZZUTO V. YORDY

       self-care, home living, social or interpersonal
       skills, use of community resources, self-
       direction, functional academic skills, work,
       leisure, health and safety. The onset of
       significant subaverage general intelligence
       functioning and significant limitations in
       adaptive functioning must occur before age
       eighteen (18) years.

       (b) “Significantly subaverage general
       intellectual functioning” means an
       intelligence quotient of seventy (70) or below.

Id. at 398 (codified at Idaho Code § 19-2515A(1)).

    In light of Atkins, Pizzuto filed a fifth petition for state
post-conviction relief, challenging his death sentence on the
ground that he was intellectually disabled. See Pizzuto I,
202 P.3d at 645. In July 2003, the state moved to summarily
dismiss Pizzuto’s petition. See id. at 646. In August 2003,
Pizzuto moved to disqualify the state trial court judge. See id.
In October 2004, Pizzuto moved for additional psychological
testing, asking that he be transported to an appropriate
medical facility for testing in connection with a
neuropsychiatric evaluation by Dr. James R. Merikangas.
Pizzuto did not notice the motion for a hearing, however. See
                         PIZZUTO V. YORDY                               11

id. at 655.3 In January 2005, the state trial court denied the
motion for disqualification. See id. at 646.

     In seeking dismissal of Pizzuto’s petition, the state argued
that the petition was untimely under Idaho law and,
alternatively, that Pizzuto had failed to establish a prima face
case of intellectual disability under the new Idaho statute.4
With respect to the latter contention, the state noted that there
were three elements of intellectual disability – subaverage
intellectual functioning, significant limitation in adaptive
functioning and an onset before age 18. With respect to the
first criterion, the state noted that Pizzuto had “a verbal IQ of
72” – based on an IQ test administered by Dr. Michael Emery
in 1985 – but that “[t]he Statute says 70 or below,” and “72
is not 70 or below.” In addition, because Pizzuto’s IQ score
of 72 was obtained when he was 28 years old, the state
argued that “we have no indication of what his IQ was – no
testing, at least – what his IQ . . . was before his 18th
birthday.” The state noted that the court had “no evidence of
an IQ test prior to age 18.”



    3
      It is not clear why Pizzuto did not notice the motion for a hearing.
At an April 2005 hearing, “Pizzuto’s counsel stated that she could not ask
the district court to rule on her motion for testing, apparently because she
believed the judge should be disqualified from presiding in the case and
therefore from ruling on the motion.” Pizzuto I, 202 P.3d at 655 & n.8.
Counsel for Pizzuto apparently concluded that, because the court had
erroneously denied the motion to disqualify, any order entered by the court
on the question of testing would be void.
    4
      Initially, the state also argued for summary dismissal on the ground
that, as a matter of state law, Atkins did not apply retroactively. See
Pizzuto I, 202 P.3d at 646. The state subsequently abandoned that
argument, however.
12                   PIZZUTO V. YORDY

    Pizzuto both opposed the state’s motion for summary
dismissal and, in September 2005, moved for summary
judgment, arguing that he had, as a matter of law, established
a prima facie case of intellectual disability. See id. Pizzuto
argued that the state trial court should deny the state’s motion
for summary dismissal and grant his motion for summary
judgment. In the alternative, Pizzuto argued that his October
2004 motion for additional testing should be granted and the
matter set for trial. See id. at 655–56 & n.9.

      In addressing whether Pizzuto had made a prima facie
showing of intellectual disability under the Idaho statute, both
sides recognized that Idaho’s requirement of an IQ of 70 or
below was inconsistent with the AAMR and American
Psychiatric Association clinical standards in effect at the
time. Counsel for Pizzuto, however, acknowledged that
Atkins did not “dictate what retardation is,” while counsel for
the state emphasized that “[t]he United States Supreme Court
said that the states were permitted to define mental
retardation . . . basically as they saw fit.” The state
recognized that the DSM and AAMR manual “talk[ed] about
. . . a 70 IQ plus or minus five,” but the state emphasized that
“the Idaho Statute doesn’t say that. [Section] 19-2515A is
very specific, 70 or below. It doesn’t say plus or minus five.
Seventy or below, period, end of story.” The state observed
that “some states have actually gone below the 70 and one
state . . . has gone to 75.” But “Idaho chose 70.”

    The state argued, moreover, that the margin of error was
of no use to Pizzuto, because his “actual” IQ was as likely to
be 77 as 67:

       [Section] 2515A says that if the Court finds
       by a preponderance of the evidence that the
                      PIZZUTO V. YORDY                        13

        defendant is mentally retarded –
        preponderance of the evidence, more likely
        than not, . . . something over 50 percent.
        Well, isn’t it just as likely that Pizzuto’s IQ is
        77 as opposed to 67?               That’s not a
        preponderance of the evidence. So, you have
        to go with the 72 and that’s the only number
        that this Court has before it, the only number.

    In December 2005, after a hearing on the motions, the
state trial court dismissed Pizzuto’s petition on the grounds
that it had not been timely filed under state law and that
Pizzuto had failed to raise a genuine issue of material fact
supporting his claim of intellectual disability. See id. at 646.
Pizzuto timely appealed to the Idaho Supreme Court. See id.

     In a 2008 decision, the Idaho Supreme Court affirmed the
state trial court’s denial of Pizzuto’s Atkins claim. See
Pizzuto I, 202 P.3d 642. The court noted that, to survive
summary dismissal, Pizzuto had to present evidence
establishing a prima facie case – i.e., enough evidence to
allow the factfinder to infer the fact at issue and rule in his
favor – on each element of his claim under § 19-2515A(1).
See id. at 650. The court interpreted the Idaho statute as
requiring proof of three elements: “(1) an intelligence
quotient (IQ) of 70 or below; (2) significant limitations in
adaptive functioning in at least two of the ten areas listed; and
(3) the onset of the offender’s IQ of 70 or below and the onset
of his or her significant limitations in adaptive functioning
both must have occurred before the offender turned age
eighteen.” Id. at 651.

   The court concluded that Pizzuto failed to establish a
prima facie case as to the first element – an IQ of 70 or
14                        PIZZUTO V. YORDY

below. The record reflected only a single IQ test score for
Pizzuto, a score of 72 on the test administered by Dr. Emery
in December 1985, shortly before Pizzuto’s 29th birthday.
See id. The court acknowledged Pizzuto’s argument that “an
IQ score is only accurate within five points,” but it found
“two problems” with Pizzuto’s argument that “his actual IQ
could have been five points lower or higher than 72”: first, it
would be just as reasonable for the state trial court to infer
that his actual IQ was 77 as it would be to infer that it was 67;
second, the state trial court was permitted to infer that his IQ
had decreased during the 11 years between his 18th birthday
and the date of his IQ test. Id.5




     5
        The Idaho Supreme Court noted that the state trial court was
permitted to draw inferences in favor of the state when considering
whether to grant summary judgment to the state. See Pizzuto I, 202 P.3d
at 650 (citing Shawver v. Huckleberry Estates, L.L.C., 93 P.3d 685,
691–92 (Idaho 2004)). It is not clear whether this line of authority – see,
e.g., Stafford v. Klosterman, 998 P.2d 1118, 1119 (Idaho 2000); E. Idaho
Agr. Credit Ass’n v. Neibaur, 944 P.2d 1386, 1389 (Idaho 1997); Wells v.
Williamson, 794 P.2d 626, 629 (Idaho 1990); Riverside Dev. Co. v.
Ritchie, 650 P.2d 657, 661 (Idaho 1982) – applies where, as here, the
nonmoving party has made clear that it does not consider the record fully
developed. See Pizzuto I, 202 P.3d at 656 n.9; cf. 10A Charles Alan
Wright et al., Federal Practice and Procedure § 2720 (4th ed. 2019)
(describing, in the text accompanying note 15, the comparable practice
under federal procedure); Int’l Bancorp, LLC v. Societe des Bains de Mer
et du Cercle des Etrangers a Monaco, 329 F.3d 359, 362 (4th Cir. 2003);
Matter of Placid Oil Co., 932 F.2d 394, 398 (5th Cir. 1991); Fox v.
Johnson & Wimsatt, 127 F.2d 729, 737 (D.C. Cir. 1942). It also is not
clear whether the state trial court in fact drew inferences in favor of the
state; the state trial court’s ruling says only that “Pizzuto failed to raise a
genuine issue of material fact supporting his claim of mental retardation.”
Pizzuto, however, does not raise these questions in his opening brief, and
so we do not address them.
                      PIZZUTO V. YORDY                        15

     The court noted that Pizzuto “did not offer any expert
opinion” showing that he “had an IQ of 70 or below at the
time of the murders and prior to his eighteenth birthday.” Id.
at 655. Accordingly, the court held that the trial court did not
err in granting summary judgment to the state. See id.

    We granted Pizzuto permission to file a successive federal
habeas petition on his Atkins claim. After additional testing
and an evidentiary hearing, the federal district court denied
Pizzuto’s petition. See Pizzuto v. Blades (Pizzuto II), No.
1:05-CV-516-BLW, 2012 WL 73236, at *21 (D. Idaho Jan.
10, 2012). We initially affirmed. See Pizzuto v. Blades
(Pizzuto III), 729 F.3d 1211, 1224 (9th Cir. 2013).

    While Pizzuto’s petition for rehearing was pending,
however, the Supreme Court decided Hall v. Florida,
572 U.S. 701 (2014). In Hall, the Supreme Court considered
a Florida law defining intellectual disability “to require an IQ
test score of 70 or less. If, from test scores, a prisoner is
deemed to have an IQ above 70, all further exploration of
intellectual disability is foreclosed.” Id. at 704. The Court
held that “[t]his rigid rule . . . creates an unacceptable risk
that persons with intellectual disability will be executed, and
thus is unconstitutional.” Id.

    At the outset, the Court held that, “[i]n determining who
qualifies as intellectually disabled, it is proper to consult the
medical community’s opinions.” Id. at 710. The Court
explained that “[t]he legal determination of intellectual
disability is distinct from a medical diagnosis, but it is
informed by the medical community’s diagnostic
framework.” Id. at 721.
16                       PIZZUTO V. YORDY

    Next, once again turning to the clinical definitions
established by the AAMR and the American Psychiatric
Association, the Court explained that “the medical
community defines intellectual disability according to three
criteria: significantly subaverage intellectual functioning,
deficits in adaptive functioning (the inability to learn basic
skills and adjust behavior to changing circumstances), and
onset of these deficits during the developmental period.” Id.
at 710 (citing American Psychiatric Association, Diagnostic
and Statistical Manual of Mental Disorders 33 (5th ed. 2013)
(DSM-5)).

    With respect to the first criterion, the Court recognized
that IQ test scores may be “of considerable significance.” Id.
at 723. The Court emphasized, however, that, “in using these
scores to assess a defendant’s eligibility for the death penalty,
a State must afford these test scores the same studied
skepticism that those who design and use the tests do, and
understand that an IQ test score represents a range rather than
a fixed number.” Id. Because “[e]ach IQ test has a ‘standard
error of measurement’” of plus or minus five points, “an
individual’s intellectual functioning cannot be reduced to a
single numerical score.” Id. at 713. Thus, “IQ test scores
should be read not as a single fixed number but as a range.”
Id. at 712. “A score of 71, for instance, is generally
considered to reflect a range between 66 and 76 . . . .” Id.
at 713.6

     6
       Although the standard error of measurement applicable here, as in
Hall, is plus or minus five points, that is not always the case. See AAIDD,
Intellectual Disability: Definition, Classification, and Systems of Supports
36 (11th ed. 2010) (AAIDD-11) (noting that the standard error of
measurement “varies by test, subgroup, and age group . . . . For well-
standardized measures of general intellectual functioning, the standard
error of measurement is approximately 3 to 5 points.”).
                         PIZZUTO V. YORDY                              17

    A court, therefore, may not cut off the inquiry when a
defendant scores between 70 and 75 on an IQ test. Rather,
“[f]or professionals to diagnose – and for the law then to
determine – whether an intellectual disability exists once the
[standard error of measurement] applies and the individual’s
IQ score is 75 or below the inquiry would consider factors
indicating whether the person had deficits in adaptive
functioning.” Id. at 714. The Court “agree[d] with the
medical experts that when a defendant’s IQ test score falls
within the test’s acknowledged and inherent margin of error,
the defendant must be able to present additional evidence of
intellectual disability, including testimony regarding adaptive
deficits.” Id. at 723.7

    The Court held that Florida’s “strict IQ test score cutoff
of 70” ran afoul of these requirements in two ways. First, it

   7
       As the DSM-5 explains:

         Individuals with intellectual disability have scores of
         approximately two standard deviations or more below
         the population mean, including a margin for
         measurement error (generally +5 points). On tests with
         a standard deviation of 15 and a mean of 100, this
         involves a score of 65–75 (70 ± 5). . . . IQ test scores
         are approximations of conceptual functioning but may
         be insufficient to assess reasoning in real-life situations
         and mastery of practical tasks. For example, a person
         with an IQ score above 70 may have such severe
         adaptive behavior problems in social judgment, social
         understanding, and other areas of adaptive functioning
         that the person’s actual functioning is comparable to
         that of individuals with a lower IQ score. Thus, clinical
         judgment is needed in interpreting the results of IQ
         tests.

DSM-5 at 37.
18                    PIZZUTO V. YORDY

“disregard[ed] established medical practice” by “tak[ing] an
IQ score as final and conclusive evidence of a defendant’s
intellectual capacity, when experts in the field would consider
other evidence.” Id. at 712. Second, it “relie[d] on a
purportedly scientific measurement of the defendant’s
abilities, his IQ score, while refusing to recognize that the
score is, on its own terms, imprecise.” Id.

    In reaching this conclusion, the Court rejected any
suggestion that Atkins had given states “unfettered discretion
to define” intellectual disability. Id. at 719. The Court said
that “[t]he clinical definitions of intellectual disability, which
take into account that IQ scores represent a range, not a fixed
number, were a fundamental premise of Atkins.” Id. at 720.
The Court added:

        If the States were to have complete autonomy
        to define intellectual disability as they wished,
        the Court’s decision in Atkins could become a
        nullity, and the Eighth Amendment’s
        protection of human dignity would not
        become a reality. This Court thus reads
        Atkins to provide substantial guidance on the
        definition of intellectual disability.

Id. at 720–21.

    Finally, in conducting a survey of state laws respecting
the execution of intellectually disabled offenders, Hall briefly
distinguished Idaho law from Florida’s strict IQ test score
cutoff. Citing the Idaho Supreme Court’s decision in
Pizzuto’s case, the Court characterized Idaho law as
“allowing a defendant to present additional evidence of
                          PIZZUTO V. YORDY                               19

intellectual disability even when an IQ test score is above
70.” Id. at 717 (citing Pizzuto I, 202 P.3d at 651).8

    In light of Hall, we withdrew our opinion, vacated the
judgment of the district court and remanded this case to the
district court. See Pizzuto v. Blades (Pizzuto IV), 758 F.3d
1178 (9th Cir. 2014).

    On remand, the district court concluded that Hall did not
alter its previous decision. See Pizzuto v. Blades (Pizzuto V),
No. 1:05-cv-00516-BLW, 2016 WL 6963030, at *11 (D.
Idaho Nov. 28, 2016). The court reasoned that relief was not
available under § 2254(d)(1), because Hall was not clearly
established law at the time of the state court decision and,
even if it were, the state court’s alternative basis for denying
relief was reasonable. See id. at *6–10. The court also
incorporated its previous conclusion that the state court’s
decision was not based on an unreasonable determination of


     8
        Idaho’s IQ requirement is less restrictive than the Florida
requirement at issue in Hall because, whereas Florida required an IQ test
score of 70, Idaho requires an “actual IQ” of 70. See Pizzuto I, 202 P.3d
at 651. Under the Florida rule, an individual with an IQ test score of 71
is altogether barred from establishing intellectual disability. Under the
Idaho rule adopted in Pizzuto’s case, that individual could establish
subaverage intellectual functioning if he could somehow show that his IQ
test score overstated his “actual IQ.” Ultimately, however, requiring an
individual to establish an “actual IQ” of 70 in order to satisfy the
intellectual functioning prong of the intellectual disability definition
suffers from a similar infirmity as the Florida rule – it fails to recognize
that “an IQ between 70 and 75 or lower . . . is typically considered the
cutoff IQ score for the intellectual function prong of the mental retardation
definition,” Atkins, 536 U.S. at 309 n.5, and it fails to recognize that,
“when the lower end of [an IQ] score range falls at or below 70, [a court
must] move on to consider [the individual’s] adaptive functioning,” Moore
v. Texas, 137 S. Ct. 1039, 1049 (2017).
20                   PIZZUTO V. YORDY

the facts under § 2254(d)(2). See id. at *10. Finally, after
reviewing the evidence again on remand, the district court
concluded that Pizzuto was not entitled to relief even under
de novo review. See id. at *10–11. This timely appeal
followed.

    In briefing this appeal, the parties have discussed not only
Atkins and Hall but also the Supreme Court’s more recent
decisions in Brumfield v. Cain, 135 S. Ct. 2269 (2015), and
Moore v. Texas (Moore I), 137 S. Ct. 1039 (2017). In
Brumfield, the Court reiterated that “an IQ test result cannot
be assessed in a vacuum” and again held, as in Hall, that “it
is unconstitutional to foreclose ‘all further exploration of
intellectual disability’ simply because a capital defendant is
deemed to have an IQ above 70.” 135 S. Ct. at 2277–78
(quoting Hall, 572 U.S. at 704). The Court also concluded
that the state court’s rejection of the petitioner’s request for
an evidentiary hearing on his Atkins claim was based on an
“unreasonable determination of the facts” under § 2254(d)(2).
See id. at 2276.

   In Moore I, the Court reaffirmed Hall’s holding that
“adjudications of intellectual disability should be ‘informed
by the views of medical experts.’” 137 S. Ct. at 1044
(quoting Hall, 572 U.S. at 721). The Court explained:

       Even if “the views of medical experts” do not
       “dictate” a court’s intellectual-disability
       determination, . . . the determination must be
       “informed by the medical community’s
       diagnostic framework.” . . . . Hall indicated
       that being informed by the medical
       community does not demand adherence to
       everything stated in the latest medical guide.
                     PIZZUTO V. YORDY                        21

       But neither does our precedent license
       disregard of current medical standards.

Id. at 1048–49 (citations omitted) (quoting Hall, 572 U.S.
at 721). Thus, the Court held that “[t]he medical
community’s current standards supply one constraint on
States’ leeway in this area.” Id. at 1053.

    Moore I also reaffirmed Hall’s holding that courts must
“continue the inquiry and consider other evidence of
intellectual disability where an individual’s IQ score, adjusted
for the test’s standard error, falls within the clinically
established range for intellectual-functioning deficits.” Id. at
1050. In Moore I, the petitioner’s average score on six IQ
tests was 70.66. See id. at 1045. Thus, the Court held that,
“[b]ecause the lower end of Moore’s score range falls at or
below 70, the [state court] had to move on to consider
Moore’s adaptive functioning.” Id. at 1049 (citing Hall,
572 U.S. at 723).

    After briefing for this appeal was completed, the Supreme
Court has twice more reviewed Atkins claims. In Shoop v.
Hill, 139 S. Ct. 504 (2019) (per curiam), the Court
“consider[ed] what was clearly established regarding the
execution of the intellectually disabled in 2008.” 139 S. Ct.
at 506–07. The Court observed that “Atkins gave no
comprehensive definition of ‘mental retardation’ for Eighth
Amendment purposes”; although Atkins cited the definitions
of intellectual disability adopted by the AAMR and the
American Psychiatric Association approvingly, it “left ‘to the
State[s] the task of developing appropriate ways to enforce
the constitutional restriction’” on executing intellectually
disabled persons. Id. at 507 (alteration in original) (quoting
Atkins, 536 U.S. at 317).
22                   PIZZUTO V. YORDY

    In the second case, Moore v. Texas (Moore II), 139 S. Ct.
666 (2019) (per curiam), the Court reaffirmed its holding in
Moore I that the petitioner, with an average IQ score of 70.66,
“had demonstrated sufficient intellectual-functioning deficits”
under the first criterion of the clinical definition of
intellectual disability “to require consideration of the second
criterion – adaptive functioning.” Id. at 668 (citing Moore I,
137 S. Ct. at 1048–50).

                STANDARD OF REVIEW

    We review de novo the district court’s denial of a habeas
petition. See Curiel v. Miller, 830 F.3d 864, 868 (9th Cir.
2016). Review of Pizzuto’s petition is governed by the
Antiterrorism and Effective Death Penalty Act of 1996
(AEDPA) because Pizzuto filed his petition after April 24,
1996. See Lindh v. Murphy, 521 U.S. 320, 322, 336 (1997).
Under AEDPA, habeas relief can be granted only if the state
court proceeding adjudicating the claim on the merits
“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,”
28 U.S.C. § 2254(d)(1), or “was based on an unreasonable
determination of the facts in light of the evidence presented
in the State court proceeding,” id. § 2254(d)(2).

    “[A] decision by a state court is ‘contrary to’ [the
Supreme Court’s] clearly established law if it ‘applies a rule
that contradicts the governing law set forth in [the Supreme
Court’s] cases’ or if it ‘confronts a set of facts that are
materially indistinguishable from a decision of th[e Supreme]
Court and nevertheless arrives at a result different from [the
Supreme Court’s] precedent.’” Price v. Vincent, 538 U.S.
634, 640 (2003) (quoting Williams v. Taylor, 529 U.S. 362,
                     PIZZUTO V. YORDY                        23

405–06 (2000)). “[A] state-court decision involves an
unreasonable application of th[e Supreme] Court’s precedent
if the state court identifies the correct governing legal rule
from th[e Supreme] Court’s cases but unreasonably applies it
to the facts of the particular state prisoner’s case.” Williams,
529 U.S. at 407. To satisfy this requirement, the record
“must show that the state court’s ruling . . . was so lacking in
justification that there was an error well understood and
comprehended in existing law beyond any possibility for
fairminded disagreement.” Harrington v. Richter, 562 U.S.
86, 103 (2011). The question “is not whether a federal court
believes the state court’s determination was incorrect but
whether that determination was unreasonable – a substantially
higher threshold.” Schriro v. Landrigan, 550 U.S. 465, 473
(2007) (citing Williams, 529 U.S. at 410). Turning to
§ 2254(d)(2), “we may only hold that a state court’s decision
was based on an unreasonable determination of the facts if
‘we [are] convinced that an appellate panel, applying the
normal standards of appellate review, could not reasonably
conclude that the finding is supported by the record.’”
Murray v. Schriro, 745 F.3d 984, 999 (9th Cir. 2014)
(alteration in original) (quoting Taylor v. Maddox, 366 F.3d
992, 1000 (9th Cir. 2004), abrogated on other grounds as
stated in Murray, 745 F.3d at 1000).

    We apply our review under § 2254(d) to the last reasoned
state court decision. See Ylst v. Nunnemaker, 501 U.S. 797,
803–04 (1991); Hibbler v. Benedetti, 693 F.3d 1140, 1146
(9th Cir. 2012). Here, we review the Idaho Supreme Court’s
2008 decision. See Pizzuto I, 202 P.3d 642. Because that
court denied Pizzuto’s Atkins claim on the merits, our review
under § 2254(d) is limited to the record that was before the
state court. See Cullen v. Pinholster, 563 U.S. 170, 181
(2011). We may grant habeas relief only if we conclude both
24                      PIZZUTO V. YORDY

that § 2254(d) is satisfied and, on de novo review, that the
petitioner is in custody in violation of the Constitution of the
United States. See Frantz v. Hazey, 533 F.3d 724, 735–37
(9th Cir. 2008) (en banc).9

                          DISCUSSION

    Pizzuto invokes both prongs of § 2254(d). He contends
that the Idaho Supreme Court’s decision was “contrary to” or
involved an “unreasonable application” of Supreme Court
precedent. See 28 U.S.C. § 2254(d)(1). Alternatively, he
contends that the state court’s decision was “based on an
unreasonable determination of the facts.”          See id.
§ 2254(d)(2). We consider these contentions in turn.

                     A. Section 2254(d)(1)

   We begin by addressing Pizzuto’s argument that the Idaho
Supreme Court’s decision was “contrary to” or involved an
“unreasonable application” of clearly established Supreme
Court precedent under § 2254(d)(1).

    After the Atkins decision, the Idaho legislature adopted
the following definition of intellectual disability:

         (a) “Mentally retarded” means significantly
         subaverage general intellectual functioning
         that is accompanied by significant limitations


     9
      We may address these two questions – the § 2254(d) inquiry and de
novo review of the constitutional claim under §§ 2241(c)(3) and 2254(a)
– in any order. See Frantz, 533 F.3d at 736. Typically, we conduct the
AEDPA inquiry first, and where, as here, § 2254(d) is not satisfied, we
need not review the constitutional claim de novo.
                     PIZZUTO V. YORDY                      25

       in adaptive functioning in at least two (2) of
       the following skill areas: communication,
       self-care, home living, social or interpersonal
       skills, use of community resources, self-
       direction, functional academic skills, work,
       leisure, health and safety. The onset of
       significant subaverage general intelligence
       functioning and significant limitations in
       adaptive functioning must occur before age
       eighteen (18) years.

       (b) “Significantly subaverage general
       intellectual functioning” means an
       intelligence quotient of seventy (70) or below.

Idaho Code § 19-2515A(1).

     In 2008, the Idaho Supreme Court applied this definition
for the first time in Pizzuto’s case. See Pizzuto I, 202 P.3d
at 650–55. The court began by noting that “the statutory
definition . . . requires proof of three elements: (1) an
intelligence quotient (IQ) of 70 or below; (2) significant
limitations in adaptive functioning in at least two of the ten
areas listed; and (3) the onset of the offender’s IQ of 70 or
below and the onset of his or her significant limitations in
adaptive functioning both must have occurred before the
offender turned age eighteen.” Id. at 651. Focusing on the
first element, the court held that, “[i]n order for Pizzuto to
have presented a prima facie case, there must be evidence
showing that he had an IQ of seventy or below before age
eighteen.” Id.

    The court then noted that the record included only one IQ
test score for Pizzuto – a Verbal IQ of 72 on the Wechsler
26                   PIZZUTO V. YORDY

Adult Intelligence Scale, Revised, administered by Dr. Emery
in December 1985, shortly before Pizzuto’s 29th birthday.
See id. This test score, the court concluded, was insufficient
to establish an IQ of 70 or below before the age of 18:

       Pizzuto argues that an IQ score is only
       accurate within five points. He contends that
       his actual IQ could have been five points
       lower or higher than 72. There are two
       problems with that argument.

           First, when enacting Idaho Code § 19-
       2515A(1), the legislature did not require that
       the IQ score be within five points of 70 or
       below. It required that it be 70 or below.
       Although Pizzuto argued that the district court
       should infer that Pizzuto’s actual IQ was
       lower than his test score, the court could just
       as reasonably have inferred that it was higher.
       The alleged error in IQ testing is plus or
       minus five points. The district court was
       entitled to draw reasonable inferences from
       the undisputed facts. It would be just as
       reasonable to infer that Pizzuto’s IQ on
       December 12, 1985, was 77 as it would be to
       infer that it was 67.

           Second, Pizzuto’s argument also requires
       the district court to infer that Pizzuto’s IQ had
       not decreased during the eleven-year period
       from his eighteenth birthday to the date of his
       IQ test. The district court, as the trier of fact,
       was not required to make that inference,
       especially in light of the opinions of Pizzuto’s
                      PIZZUTO V. YORDY                        27

        experts that his long history of drug abuse and
        his epilepsy would have negatively impacted
        his mental functioning.

Id. (citation omitted).

     Pizzuto argues that the Idaho Supreme Court’s decision
was both “contrary to” and an “unreasonable application” of
Atkins. His argument begins with the premise that Atkins
“embraced the clinical definitions of intellectual disability set
by the American Association on Mental Retardation . . . and
the American Psychiatric Association.” Opening Brief at 26
(citing Atkins, 536 U.S. at 308 n.3, 317 n.22). Then, relying
on that premise, he argues that the Idaho court disregarded
these clinical definitions by (1) applying a “hard IQ-70
cutoff” and (2) requiring him to provide the court with IQ
testing completed before his 18th birthday. Id. at 31–36.

      Specifically, Pizzuto contends that the Idaho Supreme
Court’s application of a “hard IQ-70 cutoff” disregarded the
clinical definitions by: (1) “expressly confin[ing] the
consideration of the first criteri[on] to an IQ score only,”
“tak[ing] the IQ score as final and conclusive evidence of a
defendant’s intellectual capacity when experts in the field
would consider other evidence”; (2) “reject[ing] the scientific
limitations of testing, including the standard of error
measurement . . . universally recognized by the medical
and psychological professions”; (3) “completely
misunderst[anding] the purpose and effect of the [standard
error of measurement]”; and (4) “refus[ing] to consider the
. . . Flynn Effect.” Id. at 31–32.
28                   PIZZUTO V. YORDY

     1. “Contrary to” Prong

    Initially, we reject Pizzuto’s argument that the Idaho
court’s decision was “contrary to” Atkins. For purposes of
§ 2254(d)(1), “clearly established Federal law” includes only
the holdings, as opposed to the dicta, of the Supreme Court’s
decisions. See White v. Woodall, 572 U.S. 415, 419 (2014).
Here, the Idaho Supreme Court identified the applicable
Supreme Court precedent – Atkins – and acknowledged its
holding that the Eighth Amendment prohibits the execution
of intellectually disabled offenders. See Pizzuto I, 202 P.3d
at 648. The state court’s decision, therefore, was not
“contrary to” Atkins. Although Pizzuto argues that the state
court failed to follow the clinical standards issued by the
AAMR and the American Psychiatric Association, Atkins did
not hold that these standards apply. See Shoop, 139 S. Ct.
at 507 (“Atkins gave no comprehensive definition of ‘mental
retardation’ for Eighth Amendment purposes.”). The state
court’s decision, therefore, could not have been “contrary to”
Atkins on this basis.

    We also reject Pizzuto’s suggestion that the Idaho
Supreme Court’s application of a hard IQ-70 cutoff was
“contrary to” or an “unreasonable application of” Atkins’
“progeny” – a reference to Hall, Brumfield and Moore I.
Opening Brief at 31. These three cases were decided in 2014,
2015 and 2017 respectively – years after the Idaho Supreme
Court’s 2008 decision in Pizzuto’s case. “[U]nder . . .
§ 2254(d)(1), habeas relief may be granted only if the state
court’s adjudication ‘resulted in a decision that was contrary
to, or involved an unreasonable application of,’ Supreme
Court precedent that was ‘clearly established’ at the time of
the adjudication.” Shoop, 139 S. Ct. at 506 (emphasis
added); see also Lockyer v. Andrade, 538 U.S. 63, 71–72
                     PIZZUTO V. YORDY                       29

(2003) (“‘[C]learly established Federal law’ under
§ 2254(d)(1) is the governing legal principle or principles set
forth by the Supreme Court at the time the state court renders
its decision.” (emphasis added)). The Idaho Supreme Court’s
decision, therefore, could not have been “contrary to” or an
“unreasonable application” of Atkins’ “progeny.”

   2. “Unreasonable Application” Prong

    Pizzuto’s contention that the Idaho Supreme Court’s
decision involved an “unreasonable application” of Atkins
fails as well.

    Pizzuto is correct that the Idaho Supreme Court’s
application of a “hard IQ-70 cutoff” was inconsistent with the
clinical definitions in place at the time of the state court’s
decision. The DSM-IV, adopted in 2000, defined the
diagnostic criteria for intellectual disability as:

       A. Significantly subaverage intellectual
          functioning: an IQ of approximately 70 or
          below on an individually administered IQ
          test (for infants, a clinical judgment of
          significantly subaverage intellectual
          functioning).

       B. Concurrent deficits or impairments in
          present adaptive functioning (i.e., the
          person’s effectiveness in meeting the
          standards expected for his or her age by
          his or her cultural group) in at least two of
          the following areas: communication, self-
          care, home living, social/interpersonal
          skills, use of community resources, self-
30                         PIZZUTO V. YORDY

                direction, functional academic skills,
                work, leisure, health, and safety.

            C. The onset is before age 18 years.

DSM-IV at 49 (emphasis added). This standard does not
require an IQ of 70 or below; it requires “an IQ of
approximately 70 or below.” Id. (emphasis added). Under
the DSM-IV, therefore, “it is possible to diagnose Mental
Retardation in individuals with IQs between 70 and 75 who
exhibit significant deficits in adaptive behavior.” Id.
at 41–42.10

    The 10th edition of the AAMR manual, adopted in 2002,
defined intellectual disability as follows:




     10
          Under the DSM-IV:

            Significantly subaverage intellectual functioning is
            defined as an IQ of about 70 or below (approximately
            2 standard deviations below the mean). It should be
            noted that there is a measurement error of
            approximately 5 points in assessing IQ, although this
            may vary from instrument to instrument (e.g., a
            Wechsler IQ of 70 is considered to represent a range of
            65–75). Thus, it is possible to diagnose Mental
            Retardation in individuals with IQs between 70 and 75
            who exhibit significant deficits in adaptive behavior.
            Conversely, Mental Retardation would not be
            diagnosed in an individual with an IQ lower than 70 if
            there are no significant deficits or impairments in
            adaptive functioning.

DSM-IV at 41–42.
                     PIZZUTO V. YORDY                       31

       Mental retardation is a disability characterized
       by significant limitations both in intellectual
       functioning and in adaptive behavior as
       expressed in conceptual, social, and practical
       adaptive skills. This disability originates
       before age 18.

AAMR, Mental Retardation: Definition, Classification, and
Systems of Supports 8 (10th ed. 2002). Under the intellectual
functioning prong, “[t]he criterion for diagnosis is
approximately two standard deviations below the mean,
considering the standard error of measurement for the
specific assessment instrument used and the instrument’s
strengths and weaknesses.” Id. at 37 (emphasis added). “In
effect, this expands the operational definition of mental
retardation to 75, and that score of 75 may still contain
measurement error.” Id. at 59.

     In contrast to these clinical standards, the Idaho Supreme
Court required an offender to establish an IQ of 70 or below
under all circumstances, regardless of the offender’s deficits
in adaptive functioning. Although the Idaho court recognized
that “[t]he alleged error in IQ testing is plus or minus five
points,” Pizzuto I, 202 P.3d at 651, it nonetheless required
Pizzuto to establish an “actual IQ” of 70 or below. See
Pizzuto III, 729 F.3d at 1217 n.2; Pizzuto I, 202 P.3d at 651
(“[T]he statutory definition . . . requires proof of . . . an
intelligence quotient (IQ) of 70 or below . . . . Significant
limitations in adaptive functioning alone will not bring an
offender within the protection of the statute.”); id. (“[W]hen
enacting Idaho Code § 19-2515A(1), the legislature did not
require that the IQ score be within five points of 70 or below.
It required that it be 70 or below.”). In doing so, the court
failed to recognize that “it is possible to diagnose Mental
32                   PIZZUTO V. YORDY

Retardation in individuals with IQs between 70 and 75 who
exhibit significant deficits in adaptive behavior.” DSM-IV
at 41–42. Nor did the court consider whether Pizzuto
satisfied this standard. The state court’s decision, therefore,
was contrary to the clinical definitions in place at the time.

    This conclusion alone, however, does not establish that
the Idaho Supreme Court unreasonably applied Atkins for
purposes of § 2254(d)(1). At the time of the state court’s
decision in 2008, it was not yet apparent that states were
required to define intellectual disability in accordance with
these prevailing clinical definitions. To be sure, Atkins had
cited these clinical definitions with approval, noting that
statutory definitions generally conformed to them and
explaining that “an IQ between 70 and 75 or lower . . . is
typically considered the cutoff IQ score for the intellectual
function prong of the mental retardation definition.” Atkins,
536 U.S. at 308 n.3, 309 n.5, 317 n.22. The Court, however,
did not adopt these definitions or require states to follow
them. On the contrary, the Court expressly “le[ft] to the
States the task of developing appropriate ways to enforce the
constitutional restriction upon their execution of sentences.”
Id. at 317 (alterations omitted) (quoting Ford, 477 U.S.
at 416–17).

    It is now clear that “[t]he legal determination of
intellectual disability . . . is informed by the medical
community’s diagnostic framework,” Hall, 572 U.S. at 721,
and that “[t]he medical community’s current standards supply
one constraint on States’ leeway in this area,” Moore I, 137 S.
Ct. at 1053. It was not apparent in 2008, however, that states
were required to adhere strictly to the AAMR’s and American
Psychiatric Association’s clinical standards.              We
acknowledge Hall’s statements that Atkins “provide[d]
                     PIZZUTO V. YORDY                       33

substantial guidance on the definition of intellectual
disability,” that “[t]he clinical definitions of intellectual
disability . . . were a fundamental premise of Atkins” and that
“Atkins did not give the States unfettered discretion to define
the full scope of the constitutional protection.” Hall,
572 U.S. at 719–21. The Supreme Court, however, has held
that “Atkins gave no comprehensive definition of ‘mental
retardation’ for Eighth Amendment purposes.” Shoop, 139 S.
Ct. at 507; see also Bobby v. Bies, 556 U.S. 825, 831 (2009)
(explaining that Atkins “did not provide definitive procedural
or substantive guides for determining when a person who
claims mental retardation ‘will be so impaired as to fall
within Atkins’ compass’” (alteration omitted) (quoting Atkins,
536 U.S. at 317)); Ybarra v. Filson, 869 F.3d 1016, 1024 (9th
Cir. 2017) (“Significantly, Atkins ‘did not provide definitive
procedural or substantive guides’ to determine who qualifies
as intellectually disabled.” (quoting Bies, 556 U.S. at 831));
Moormann v. Schriro, 672 F.3d 644, 648 (9th Cir. 2012)
(“The Supreme Court in Atkins did not define mental
retardation as a matter of federal law.”).

    This is not a case in which the state court utterly
disregarded the clinical definitions. To be sure, the Idaho
Supreme Court erred by defining the significantly subaverage
intellectual functioning criterion as an IQ of 70 or below, see
Idaho Code § 19-2515A(1)(b); Pizzuto I, 202 P.3d at 651,
rather than “an IQ of approximately 70 or below,” DSM-IV
at 49 (emphasis added), and it erred by disregarding the
portions of the clinical standards recognizing that “it is
possible to diagnose Mental Retardation in individuals with
IQs between 70 and 75 who exhibit significant deficits in
adaptive behavior,” id. at 41–42. In other respects, however,
§ 19-2515A(1) tracks the clinical definitions cited by Atkins.
See Atkins, 536 U.S. at 308 n.3. In contrast to Hall,
34                   PIZZUTO V. YORDY

moreover, the Idaho court at least recognized the existence of
a standard error of measurement of plus or minus five points
and afforded Pizzuto an opportunity to “present additional
evidence of intellectual disability even when an IQ test score
is above 70.” Hall, 572 U.S. at 717.

     In short, because it was not apparent in 2008 that states
were required to adhere closely to the clinical definitions of
intellectual disability, the Idaho Supreme Court’s application
of a “hard IQ-70 cutoff” was not an “unreasonable
application” of Atkins.         “[R]elief is available under
§ 2254(d)(1)’s unreasonable-application clause if, and only if,
it is so obvious that a clearly established rule applies to a
given set of facts that there could be no ‘fairminded
disagreement’ on the question.” Woodall, 572 U.S. at 427
(quoting Richter, 562 U.S. at 103). We cannot say that this
standard has been satisfied here.

    Relatedly, it is now clear as a matter of federal law that
“an individual with an IQ test score ‘between 70 and 75 or
lower’ may show intellectual disability by presenting
additional evidence regarding difficulties in adaptive
functioning.” Hall, 572 U.S. at 722 (citation omitted)
(quoting Atkins, 536 U.S. at 309 n.5); see id. at 723 (“[W]hen
a defendant’s IQ test score falls within the test’s
acknowledged and inherent margin of error, the defendant
must be able to present additional evidence of intellectual
disability, including testimony regarding adaptive deficits.”);
Brumfield, 135 S. Ct. at 2278 (“[I]t is unconstitutional to
foreclose ‘all further exploration of intellectual disability’
simply because a capital defendant is deemed to have an IQ
above 70.” (quoting Hall, 572 U.S. at 704)); Moore I, 137 S.
Ct. at 1049 (“Because the lower end of Moore’s score range
falls at or below 70, the [state court] had to move on to
                     PIZZUTO V. YORDY                        35

consider Moore’s adaptive functioning.”); DSM-5 at 37
(“Individuals with intellectual disability have scores of
approximately two standard deviations or more below the
population mean, including a margin for measurement error
(generally +5 points). On tests with a standard deviation of
15 and a mean of 100, this involves a score of 65–75 (70 ±
5).”); id. (“IQ test scores are approximations of conceptual
functioning but may be insufficient to assess reasoning in
real-life situations and mastery of practical tasks. For
example, a person with an IQ score above 70 may have such
severe adaptive behavior problems in social judgment, social
understanding, and other areas of adaptive functioning that
the person’s actual functioning is comparable to that of
individuals with a lower IQ score.”); AAIDD-11 at 35
(“[T]he intellectual functioning criterion for diagnosis of
[intellectual disability] is approximately two standard
deviations below the mean, considering the standard error of
measurement . . . . The intent of this definition is not to
specify a hard and fast cutoff point/score for meeting the
significant limitations in intellectual functioning criterion
. . . . In addition, significant limitations in intellectual
functioning is only one of the three criteria used to establish
a diagnosis of [intellectual disability].”); id. at 40 (“A fixed
point cutoff score for [intellectual disability] is not
psychometrically justifiable.”). The Idaho Supreme Court
violated this principle by requiring an “actual” IQ of 70 or
below. This point, however, was not beyond fairminded
disagreement in 2008. We cannot say, therefore, that the
Idaho Supreme Court’s application of Atkins “was so lacking
in justification that there was an error well understood and
comprehended in existing law beyond any possibility for
fairminded disagreement.” Richter, 562 U.S. at 103.
36                        PIZZUTO V. YORDY

    We reach the same conclusion with respect to the Idaho
Supreme Court’s failure to apply the Flynn effect.11 Although
mentioned in recent clinical standards, see DSM-5 at 37;
AAIDD-11 at 37, Atkins did not discuss the Flynn effect, and
clinical standards in existence at the time of the Idaho
Supreme Court’s decision in 2008 did not discuss the need to
adjust IQ test scores to account for the use of outdated test
norms. Thus, “it cannot be said that the [state court’s] failure
to consider and apply the Flynn Effect is contrary to, or an
unreasonable application of, clearly established federal law.”
Hooks v. Workman, 689 F.3d 1148, 1170 (10th Cir. 2012).

    Finally, we reject Pizzuto’s contention that the Idaho
Supreme Court’s decision was contrary to or an unreasonable
application of Atkins because the court required him to
provide the results of an IQ test administered before his 18th
birthday. With respect to this contention, we simply disagree


     11
        The Flynn effect refers to the observation that IQ scores have been
increasing over time. See AAIDD-11 at 37; Smith v. Ryan, 813 F.3d 1175,
1184 (9th Cir. 2016) (“The basic premise of the Flynn effect is that
because average IQ scores increase over time, a person who takes an IQ
test that has not recently been normed against a representative sample of
the population will receive an artificially inflated IQ score.” (emphasis
omitted)). In light of this effect, the AAIDD has indicated that “best
practices require recognition of a potential Flynn Effect when older
editions of an intelligence test (with corresponding older norms) are used
in the assessment or interpretation of an IQ score.” AAIDD-11 at 37. “In
cases where a test with aging norms is used, a correction for the age of the
norms is warranted.” Id.; see Smith, 813 F.3d at 1185 (noting that the
AAIDD-11 “recognizes the existence of the Flynn Effect and recommends
correcting for the age of norms in outdated tests”). The DSM-5 likewise
identifies the Flynn effect as one of several “[f]actors that may affect test
scores.” DSM-5 at 37. Here, Pizzuto argues that, when his IQ score of 72
is adjusted for the Flynn effect, “it becomes a score of 70.” Opening Brief
at 33 n.2.
                     PIZZUTO V. YORDY                       37

with Pizzuto’s reading of the Idaho Supreme Court’s
decision. If the state court had required Pizzuto to present a
pre-18 IQ test score, it could have disposed of his claim
simply by noting the absence of such a score in the record.
Instead, it explained that “there must be evidence showing
that [Pizzuto’s] IQ was 70 or below prior to his eighteenth
birthday,” Pizzuto I, 202 P.3d at 651, regardless of when he
was tested.

                            ***

    In sum, the record does not establish that the Idaho
Supreme Court’s decision was “contrary to” or involved an
“unreasonable application” of clearly established Supreme
Court precedent. See 28 U.S.C. § 2254(d)(1). Although the
state court’s decision was contrary to clinical standards in
place at the time, it was not obvious at that time that strict
adherence to the clinical standards was required. Similarly,
although the state court’s requirement of an IQ of 70 or below
is contrary to Hall, Brumfield and Moore I, these decisions all
postdated the state court’s decision, and it was not obvious
under Atkins alone that, for Eighth Amendment purposes, “an
individual with an IQ test score ‘between 70 and 75 or lower’
may show intellectual disability by presenting additional
evidence regarding difficulties in adaptive functioning.”
Hall, 372 U.S. at 722 (citation omitted) (quoting Atkins,
536 U.S. at 309 n.5). Cf. Shoop, 139 S. Ct. at 508 (“Although
the Court of Appeals asserted that the holding in Moore was
‘merely an application of what was clearly established by
Atkins,’ the court did not explain how the rule it applied can
be teased out of the Atkins Court’s brief comments about the
meaning of what it termed ‘mental retardation.’” (citation
omitted)); Ybarra, 869 F.3d at 1024–25 (“[A]lthough Ybarra
insists that the Nevada Supreme Court unreasonably applied
38                   PIZZUTO V. YORDY

Atkins, he relies almost exclusively on the Supreme Court’s
subsequent, more detailed decisions in Moore, Hall, and
Brumfield. These decisions might redefine and expand
Atkins, but they cannot show that the Nevada Supreme Court
applied Atkins in a way that ‘was so lacking in justification
that there was an error well understood and comprehended in
existing law beyond any possibility for fairminded
disagreement.’” (footnote omitted) (quoting Richter, 562 U.S.
at 103)).

                   B. Section 2254(d)(2)

    Pizzuto alternatively contends that the Idaho Supreme
Court’s decision “was 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)(2).

    Under § 2254(d)(2), we may not characterize a state
court’s factual determinations as unreasonable “merely
because [we] would have reached a different conclusion in
the first instance.” Brumfield, 135 S. Ct. at 2277 (alteration
in original) (quoting Wood v. Allen, 558 U.S. 290, 301
(2010)). “Instead, § 2254(d)(2) requires that we accord the
state trial court substantial deference.” Id. “If ‘[r]easonable
minds reviewing the record might disagree about the finding
in question, on habeas review that does not suffice to
supersede the trial court’s . . . determination.’” Id.
(alterations in original) (quoting Wood, 558 U.S. at 301).

    Here, Pizzuto challenges the state court’s factual
determinations on several grounds. We address them in turn.
                     PIZZUTO V. YORDY                       39

   1. Pizzuto’s Argument That the State Court’s
      Determinations Are Unreasonable Because They
      Are Inconsistent with Clinical Definitions

    Pizzuto argues that the Idaho Supreme Court’s factual
determinations “are unreasonable because they are not
consistent with clinical definitions and best practices in
defining and diagnosing [intellectual disability] as guaranteed
by the Eighth Amendment in Atkins and enforced in Hall.”
Opening Brief at 37. He maintains that “[t]he state court’s
factual findings are unreasonable in light of the record before
it because they are in direct conflict with professional
standards established to determine intellectual disability and
thus, not ‘informed by’ them as instructed by Hall.” Id. at 38.

    As noted, we agree with Pizzuto that the Idaho Supreme
Court failed to apply the clinical standards in use at the time
of its decision. Those standards required an IQ of
“approximately 70” and recognized that “it is possible to
diagnose Mental Retardation in individuals with IQs between
70 and 75 who exhibit significant deficits in adaptive
behavior.” DSM-IV at 41–42. The Idaho Supreme Court, by
contrast, required an “actual” IQ of “70 or below,”
irrespective of “[s]ignificant limitations in adaptive
functioning.” Pizzuto I, 202 P.3d at 651. Pizzuto, therefore,
is correct in arguing that the state court’s determination that
he failed to make a prima facie showing of intellectual
disability is “not consistent with clinical definitions”
discussed in Atkins and subsequently required by Hall.

    Under § 2254(d)(2), however, we review a state court’s
factual determinations, not its legal conclusions. Here, the
Idaho Supreme Court did not purport to determine whether
Pizzuto was intellectually disabled under the clinical
40                   PIZZUTO V. YORDY

definitions. Instead, it determined only that Pizzuto failed to
make a prima facie “showing that his IQ was 70 or below
prior to his eighteenth birthday.” Id. It is that factual
determination, therefore, that we may review under
§ 2254(d)(2), not the state court’s legal conclusion that an IQ
of 70 or below was required. Accordingly, we must reject
Pizzuto’s contention that the state court’s factual
determinations are unreasonable merely because the state
court did not apply the clinical definitions of intellectual
disability.

     2. Pizzuto’s Argument That the State Court’s
        Unreasonably Failed to Consider His School
        Records as Evidence of Subaverage Intellectual
        Functioning

    Pizzuto argues that the Idaho Supreme Court’s
determination that he failed to make a prima facie showing
that his IQ was 70 or below before his 18th birthday was
unreasonable because it focused exclusively on his single IQ
test score while ignoring other evidence of subaverage
intellectual functioning in the form of his “abysmal school
record.” Opening Brief at 39.

    Pizzuto is correct that a “state-court fact-finding process
is undermined where the state court has before it, yet
apparently ignores, evidence that supports petitioner’s claim.”
Taylor, 366 F.3d at 1001. Here, however, Pizzuto has not
shown that the Idaho Supreme Court ignored such evidence.

    First, although Pizzuto cites his “abysmal school record,”
the actual evidence in the record regarding his schooling is
sparse and incomplete. It consists solely of affidavits from
five educators, two of whom have no specific recollection of
                     PIZZUTO V. YORDY                        41

Pizzuto. Although some of these records show that Pizzuto
received low grades and was held back, there are many
reasons Pizzuto may have performed poorly in school, and no
expert opined that this poor performance was evidence of
significantly subaverage intellectual functioning or an IQ of
70 or below. Thus, even if Pizzuto’s school records are some
evidence of pre-18 significantly subaverage intellectual
functioning, they do not render unreasonable the Idaho
Supreme Court’s determination that Pizzuto failed to make a
prima facie showing that he had an IQ of 70 or below before
the age of 18. School records can be strong evidence of
intellectual disability. See, e.g., Moore I, 137 S. Ct. at 1051;
Hall, 572 U.S. at 705, 712; Smith, 813 F.3d at 1186. Here,
however, the records do not show that the state court’s
determination was objectively unreasonable under
§ 2254(d)(2)’s demanding standard.

    Second, we cannot say that the Idaho Supreme Court
ignored this evidence within the meaning of Taylor when it
was Pizzuto himself who failed to bring the evidence to the
court’s attention. In state court, Pizzuto cited his school
records to show limitations in adaptive functioning but not to
establish subaverage intellectual functioning. To establish
the latter, Pizzuto instead “relied solely upon Dr. Emery’s IQ
determination.” Pizzuto I, 202 P.3d at 652. The state court’s
focus on Pizzuto’s IQ test score, therefore, was consistent
with Pizzuto’s own contentions.
42                    PIZZUTO V. YORDY

     3. Pizzuto’s Argument That the State Court
        Unreasonably Determined That His IQ Could
        Have Declined in Adulthood Due to Drug Abuse
        and Epilepsy

   Pizzuto argues that it was unreasonable for the Idaho
Supreme Court to determine that his IQ could have declined
between the time he was 18 (in 1974) and the time of Dr.
Emery’s IQ testing (in 1985).

    The Idaho Supreme Court determined that the state trial
court could have inferred that Pizzuto’s IQ “decreased during
the eleven-year period from his eighteenth birthday to the
date of his IQ test . . . , especially in light of the opinions of
Pizzuto’s experts that his long history of drug abuse and his
epilepsy would have negatively impacted his mental
functioning.” Pizzuto I, 202 P.3d at 651.

    Pizzuto contends that this determination was
unreasonable. First, he argues that “incidents of drug use and
epilepsy, if they occurred, would be documented,” because he
spent nine of these 11 years in prison. Opening Brief at 40.
Because his prison records do not show continued seizures or
drug use, Pizzuto argues that a “more reasonable inference”
would be that he was substantially drug free and not
experiencing seizures after he turned 19. Id. at 41–42.

    The Idaho Supreme Court’s determination, however, was
based on record evidence from Pizzuto’s own experts. In
1988, Dr. James Merikangas noted that Pizzuto had “a life
long history of almost continuous drug abuse including
intravenous Heroin as well as cocaine, speed and marijuana”;
that Pizzuto’s “long history of polydrug abuse has caused him
further neurological dysfunction and . . . substantial defects
                      PIZZUTO V. YORDY                         43

of mind and reason”; and that “[w]e will probably not know
to any scientific degree of accuracy what his state of mind
was at the time of the alleged crimes.” In 2004, Dr. Craig
Beaver opined that Pizzuto would benefit from further
neurological study in part because, “[o]ften, patients that have
persistent seizure disorders . . . will decline over time in their
overall mental abilities”:

        Mr. Pizzuto has continued to require
        pharmacological management of his seizure
        disorder since he was last examined by myself
        in 1996.       He has continued to have
        neurological difficulties. Therefore, given
        that it has now been over eight years since his
        last comprehensive neuropsychological
        examination, I would strongly recommend
        that he undergo repeat neuropsychometric
        studies. Repeat neuropsychometric studies
        are needed to better determine Gerald
        Pizzuto’s cognitive abilities. Often, patients
        that have persistent seizure disorders, for
        example, will decline over time in their
        overall mental abilities.

    In light of this evidence, it was not unreasonable for the
Idaho Supreme Court to determine that the state trial court
reasonably could have inferred that Pizzuto’s IQ may have
declined as a result of drug abuse or epilepsy. Even if, as
Pizzuto contends, a “more reasonable inference” would be
that he was substantially drug free and not experiencing
seizures after he turned 19, this does not render the state
court’s contrary determination objectively unreasonable
under § 2254(d)(2).
44                   PIZZUTO V. YORDY

    Second, Pizzuto argues that it would have been
unreasonable to infer from Dr. Beaver’s 2004 affidavit that
Pizzuto’s mental functioning may have declined between
1974 and 1985, see Pizzuto I, 202 P.3d at 652, because
“[t]here is no statement in the affidavit that Mr. Pizzuto’s IQ
had declined . . . between 1996 and 2008,” let alone “any
statement that Mr. Pizzuto’s IQ had declined . . . from his
18th birthday to the time of Dr. Emery’s testing.” Opening
Brief at 42. Dr. Beaver’s affidavit, however, clearly gave the
impression that Pizzuto’s mental functioning may have
declined between 1996 and 2004. It would not have been
unreasonable, therefore, to infer that it also might have
declined between 1974 and 1985. Dr. Beaver did not need to
expressly state that a decline in IQ occurred for the Idaho
Supreme Court to determine that it was possible. The very
reason Dr. Beaver requested more testing was that those with
persistent seizure disorders, like Pizzuto, tend to decline in
their mental abilities over time. The Idaho Supreme Court’s
determination, therefore, was not unreasonable.

     4. Pizzuto’s Argument That the State Court’s Denial
        of an Evidentiary Hearing Was Based on an
        Unreasonable Determination of the Facts

    Pizzuto argues that he “only needed to raise a reasonable
doubt regarding his intellectual capacity to be entitled to an
evidentiary hearing” and that the Idaho Supreme Court’s
determination that he “did not meet that low threshold was
unreasonable” under § 2254(d)(2). Opening Brief at 46.

    This argument is unpersuasive. First, although Pizzuto
argues that the Idaho Supreme Court unreasonably
determined that he did not raise a reasonable doubt regarding
his intellectual capacity, the Idaho Supreme Court in fact
                     PIZZUTO V. YORDY                        45

never addressed that question. The only question the state
court decided was whether Pizzuto had made a prima facie
showing of intellectual disability, in particular whether he had
made a prima facie showing of a pre-18 IQ of 70 or below.
The court did not address whether Pizzuto had raised a
“reasonable doubt” as to his intellectual disability.
Accordingly, there is no “reasonable doubt” determination for
us to review under § 2254(d)(2).

    Second, although Pizzuto contends that the Idaho
Supreme Court’s failure to apply a “reasonable doubt”
standard was “contrary to, and an unreasonable application of
Atkins,” as “expressly addressed in Brumfield,” we must
disagree. Opening Brief at 46. Atkins did not address the
legal standard applicable to a request for an evidentiary
hearing. In Brumfield, the state courts adopted a reasonable
doubt standard, see Brumfield, 135 S. Ct. at 2274, and the
Supreme Court presumed that this standard would be
consistent with Atkins, see id. at 2276 (“[W]e do not question
the propriety of the legal standard the trial court applied, and
presume that a rule according an evidentiary hearing only to
those capital defendants who raise a ‘reasonable doubt’ as to
their intellectual disability is consistent with our decision in
Atkins.”). The Court, however, did not adopt a reasonable
doubt standard. See id. The Idaho Supreme Court’s failure
to apply such a standard, therefore, was not “contrary to” or
an “unreasonable application” of Atkins. See 28 U.S.C.
§ 2254(d)(1).

   5. Pizzuto’s Argument That the State Court’s
      Factfinding Process Was Unreasonable

   Pizzuto argues more broadly that the denial of a hearing,
as well as the denial of access to an expert, rendered the
46                   PIZZUTO V. YORDY

Idaho Supreme Court’s factfinding             process    itself
unreasonable under § 2254(d)(2).

    As we explained in Hibbler, 693 F.3d at 1146,
“[c]hallenges under § 2254(d)(2) fall into two main
categories.” “First, a petitioner may challenge the substance
of the state court’s findings and attempt to show that those
findings were not supported by substantial evidence in the
state court record.” Id. Second, as relevant here, “a
petitioner may challenge the fact-finding process itself on the
ground that it was deficient in some material way.” Id. In
some circumstances, for instance, a “state court’s failure to
hold an evidentiary hearing may render its fact-finding
process unreasonable under § 2254(d)(2).” Id. at 1147.

     The Idaho Supreme Court did not specifically address
whether the state trial court erred by granting summary
judgment to the state on Pizzuto’s Atkins claim without
holding an evidentiary hearing. The court, however,
addressed a related question – whether the state trial court
erred by dismissing Pizzuto’s petition without permitting
further testing. See Pizzuto I, 202 P.3d at 655–56. The court
concluded that the trial court did not err. First, the court
noted that Pizzuto had not pursued the motion for testing.
Pizzuto had moved for additional testing in October 2004 but
he “did not notice this motion for a hearing.” Id. at 655.
Instead, “[w]ithout pursuing the motion for testing, Pizzuto
moved for summary judgment on September 23, 2005.” Id.
He did so, moreover, even though, under Idaho law, “[i]f a
trial court denies a party’s motion for summary judgment, it
has discretion to grant summary judgment to the opposing
party.” Id. at 656 (citing Hardwood v. Talbert, 39 P.3d 612,
617 (Idaho 2001)). Even in connection with the summary
judgment proceedings, “Pizzuto did not ask the [state trial]
                      PIZZUTO V. YORDY                        47

court to rule on his motion for the specified additional
testing.” Id.

    Second, as framed by the Idaho Supreme Court, the
central issue in the case was whether Pizzuto could establish
a pre-18 IQ of 70 or below. Pizzuto did not argue that, were
he afforded the opportunity to conduct further testing, he
would develop additional evidence on that question. The
court reasoned:

            The definition of “mentally retarded” in
        Idaho Code § 19-2515A requires that the
        defendant have an IQ of 70 or below both at
        the time of the murder(s) and prior to age
        eighteen. In its briefing opposing Pizzuto’s
        motion for summary judgment, the State
        argued that Pizzuto had failed to provide
        evidence that his IQ was 70 or below and
        failed to provide evidence showing it was 70
        or below prior to his eighteenth birthday.
        Pizzuto’s alleged IQ is obviously a matter
        requiring expert testimony. He did not offer
        any expert testimony opining that his IQ was
        ever 70 or below, nor does he allege that the
        requested additional testing was intended to
        address that issue.

Id. (emphasis added).

    In short, Pizzuto did not pursue his motion for additional
testing, and he did not contend that further factual
development of the record would shed additional light on the
dispositive issue – his ability to establish a pre-18 IQ of 70 or
below. Under these circumstances, we cannot say that the
48                   PIZZUTO V. YORDY

denial of an evidentiary hearing rendered the state court’s
factfinding process unreasonable under § 2254(d)(2)’s highly
deferential standard. See Hibbler, 693 F.3d at 1146–47
(“[W]hen the challenge is to the state court’s procedure, mere
doubt as to the adequacy of the state court’s findings of fact
is insufficient; we must be satisfied that any appellate court
to whom the defect in the state court’s fact-finding process is
pointed out would be unreasonable in holding that the state
court’s fact-finding process was adequate.” (alterations and
internal quotation marks omitted)).

     6. Pizzuto’s Remaining § 2254(d)(2) Arguments

    The § 2254(d)(2) portion of Pizzuto’s opening brief
appears to fault the Idaho Supreme Court’s decision on
several other grounds. The brief says, for example, that the
Idaho Supreme Court’s decision “rests on an irregular
application of Idaho law.” Opening Brief at 37. It also
asserts that the state court’s denial of an evidentiary hearing
violated Idaho Code § 19-2515A, as well as the
“requirements of Due Process and Equal Protection.” Id.
at 44. Pizzuto’s brief, however, does not “specifically and
distinctly” argue these issues. See United States v. Kama,
394 F.3d 1236, 1238 (9th Cir. 2005). We therefore decline to
address them. See id.

                            ***

    In sum, the record does not establish that the Idaho
Supreme Court’s decision was based on an unreasonable
determination of the facts under § 2254(d)(2).
                      PIZZUTO V. YORDY                        49

                       CONCLUSION

    Because § 2254(d) is not satisfied, we hold that the
district court properly denied habeas relief. We need not
address Pizzuto’s remaining appellate arguments or review
his Atkins claim de novo. Accordingly, we do not address
whether Pizzuto is intellectually disabled or whether his
execution would violate the Eighth Amendment.

    Our decision, however, does not preclude the Idaho courts
from reconsidering those questions in light of intervening
events. Although the Idaho courts rejected Pizzuto’s Atkins
claim in 2008, they did so without the benefit of an
evidentiary hearing, without the benefit of the Supreme
Court’s decisions in Hall, Brumfield and Moore I, and
without the benefit of the most recent iterations of the
AAIDD and American Psychiatric Association clinical
standards. Since 2008, the United States Supreme Court has
made clear that “it is unconstitutional to foreclose ‘all further
exploration of intellectual disability’ simply because a capital
defendant is deemed to have an IQ above 70,” Brumfield,
135 S. Ct. at 2278 (quoting Hall, 572 U.S. at 704), and the
professional clinical standards now advise that “best practices
require recognition of a potential Flynn Effect when older
editions of an intelligence test (with corresponding older
norms) are used in the assessment or interpretation of an IQ
score,” AAIDD-11 at 37. The Idaho courts have not yet
addressed whether, under these standards, Pizzuto’s execution
would violate the Eighth Amendment.

    The judgment of the district court is affirmed. Each party
shall bear its own costs on appeal.

    AFFIRMED.
