Elroy Chester v. Rick Thaler, Director , 666 F.3d 340 ( 2012 )


Menu:
  •                 REVISED JANUARY 3, 2012
    IN THE UNITED STATES COURT OF APPEALS
    FOR THE FIFTH CIRCUIT   United States Court of Appeals
    Fifth Circuit
    FILED
    December 30, 2011
    No. 08-70023                        Lyle W. Cayce
    Clerk
    ELROY CHESTER,
    Petitioner - Appellant
    v.
    RICK THALER, DIRECTOR, TEXAS DEPARTMENT OF CRIMINAL
    JUSTICE, CORRECTIONAL INSTITUTIONS DIVISION,
    Respondent - Appellee
    Appeal from the United States District Court
    for the Eastern District of Texas
    Before JONES, Chief Judge, and STEWART and DENNIS, Circuit Judges.
    EDITH H. JONES, Chief Judge:
    Petitioner Elroy Chester (“Petitioner”) confessed and pled guilty to capital
    murder and was sentenced to death by a Texas jury.           His conviction and
    sentence were affirmed on direct appeal. He sought post-conviction relief from
    the Texas courts, alleging that he is mentally retarded, and his execution will
    therefore be unconstitutional. The Texas trial court and Court of Criminal
    Appeals determined that Chester was not mentally retarded. Petitioner then
    applied for a writ of habeas corpus via 28 U.S.C. § 2254. The federal district
    court denied relief, and he now appeals. The state’s legal conclusions neither
    contradicted nor unreasonably applied federal law, nor were its factual
    No. 08-70023
    conclusions unreasonable in light of the evidence presented in the state
    proceedings. See 28 U.S.C. § 2254(d)(1)-(2); Riddle v. Cockrell, 
    288 F.3d 713
    , 716
    (5th Cir. 2002). We therefore AFFIRM.
    BACKGROUND
    In 1997 and 1998, Petitioner embarked on a criminal spree too long and
    too gruesome to recount here in its full detail. He perpetrated at least five
    burglaries and five non-lethal assaults; worse, he left in his wake the victims,
    ranging from ten to eighty-seven years old, of at least five murders and three
    rapes. Petitioner’s career as a serial murderer and rapist culminated in the
    events of February 6, 1998, when his final victim, Willie Ryman III, discovered
    Petitioner raping his nieces, and Petitioner shot and killed Ryman.
    On that evening, Erin DeLeon was at home alone with her small child.
    After cutting the telephone wires and tampering with the security light between
    the garage and house, Petitioner entered the house through the unlocked
    kitchen door, wearing a ski-mask and gloves. With a gun to the back of Erin’s
    head and her ponytail in his hand, he led her from room to room to retrieve
    valuables. He then brought her to the living room and ordered her to turn off
    the lights and draw the blinds. When Claire DeLeon, Erin’s sister, returned to
    the home with her boyfriend Tim, Petitioner demanded their money and jewelry,
    then ordered them into the bathroom. Alone again with Erin, he forced her to
    undress, then blindfolded her with duct tape. He then ordered Tim to return,
    forced him to strip as well, and restrained him with duct tape. Finally he
    ordered Claire to enter and strip and blindfolded her with duct tape. He raped
    Erin and forced other sex acts, holding a gun against her head and threatening
    2
    No. 08-70023
    to “blow her head off” if she resisted. He repeated this threat when he forced
    Claire to perform sex acts.
    Willie Ryman III, the DeLeon sisters’ uncle, arrived at this scene with his
    girlfriend Marcia Sharp, who stayed in the car while Ryman approached the
    house. Petitioner went to the back door and murdered Ryman with a single
    shot. He then approached the car, where he began shooting at its locked doors.
    He fired two more shots into the car before fleeing the scene.
    Chester was quickly implicated and captured. He confessed to Ryman’s
    murder and led police to the murder weapon. Although he lied to the police
    about where it was hidden, and about the fact that it was loaded, apparently
    trying to mount a violent escape, he did not succeed. He also confessed to a host
    of other horrific crimes.     After pleading guilty to capital murder, he was
    sentenced to death by a Texas jury. His conviction and sentence were affirmed
    on direct appeal. Chester sought post-conviction relief at the state and federal
    levels on the grounds that he could not be executed because he is mentally
    retarded. Relying on the United States Supreme Court’s opinion in Atkins v.
    Virginia, 
    536 U.S. 304
    (2002) (holding that the execution of the mentally
    retarded violates the Eighth Amendment), and on the factors set forth in Ex
    Parte Briseno, 
    135 S.W.3d 1
    , 5 (Tex. Crim. App. 2004) (implementing Atkins), the
    use of which our court has repeatedly blessed, the Texas trial court and Texas
    Court of Criminal Appeals (“TCCA”) determined that Chester was not mentally
    retarded. Ex parte Chester, 
    2007 WL 602607
    (Tex. Cr. App. 2007) (unpublished)
    (“Chester I”).
    The TCCA’s detailed and thorough opinion concluded that Chester met two
    of   the   three   necessary     requirements    for   a   finding   of   m ental
    3
    No. 08-70023
    retardation–significant limitations in intellectual functioning and deficiencies
    that appeared early in life–but that he did not show “significant deficits in
    adaptive behavior.” 
    Id. at *3-*4.
    It cited Briseno for the proposition “that courts
    should use the definitions of mental retardation as stated by the American
    Association of Mental Retardation” and for a suggested serious of questions
    which would assist in determining the existence of deficits in adaptive behavior.
    
    Id. at *1.
    It acknowledged that these suggested questions were “intended only
    to be guidelines for the trial courts” to help them make the mental retardation
    determination required by Atkins “until the Legislature was to . . . establish
    conclusively both the substantive laws and the procedures that would bring our
    codes into compliance with the mandate issued by Atkins.” 
    Id. at *3.
    The
    legislature had not intervened, however, and so the Briseno factors remained the
    only legal guidance for lower Texas courts in applying the AARM definition and
    determining the presence or absence of “significant deficits in adaptive
    behavior.” 
    Id. The TCCA
    concluded that the trial court’s finding that Petitioner failed to
    demonstrate significant deficits in adaptive behavior was supported by the
    evidence. The trial court had heard Petitioner’s evidence regarding his 1987
    “Vineland test,” on which he achieved a Vineland Adaptive Behavioral Scales
    score (“VABS”) which would typically indicate mild mental retardation. It also,
    however, heard evidence regarding Chester’s classification during his school
    years as “learning disabled” (rather than retarded), and found more credible the
    testimony of a diagnostician who testified that Petitioner’s school records were
    accurate and that a “learning disability” designation does not imply mental
    retardation. It also noted the planned nature of Petitioner’s crimes, both the
    4
    No. 08-70023
    capital crime and other crimes, in which Petitioner took a great many steps to
    avoid detection.    It noted that he acted independently rather than as an
    accomplice.     The trial court considered conflicting testimony regarding
    Petitioner’s ability to converse coherently, and found more credible the testimony
    of the expert who testified that Petitioner could converse coherently on a wide
    range of topics. It found that Petitioner could lie and hide facts to protect
    himself, as evidenced by his scheme to mislead investigators in order to obtain
    his loaded gun while in custody. The TCCA therefore affirmed the trial court’s
    factual finding that Petitioner failed to demonstrate significant deficits in
    adaptive behavior by a preponderance of the evidence. 
    Id. at *9.
          Petitioner then applied for a writ of habeas corpus pursuant to
    28 U.S.C. § 2254, now alleging (as he must) not only his own mental retardation
    and the resulting unconstitutionality of his sentence, but that the TCCA’s
    determination was contrary to and an unreasonable application of the holding
    of Atkins, and that the TCCA’s decision was based on an unreasonable finding
    of fact in light of the record before it. The federal district court denied relief, and
    he appealed.
    DISCUSSION
    I.    AEDPA Review
    28 U.S.C. § 2254(d) bars relitigation of any claim “adjudicated on the
    merits” in state court, subject only to exceptions in Section 2254(d)(1) and (d)(2).
    Harrington v. Richter, 
    131 S. Ct. 770
    , 784 (2011). Section 2254(d)(1) contains
    two overlapping but distinct exceptions: an “unreasonable application” prong and
    a “contrary to” prong.      See Terry Williams v. Taylor, 
    529 U.S. 362
    , 404,
    
    120 S. Ct. 1495
    , 1519 (2000).       Federal courts may not grant habeas relief
    5
    No. 08-70023
    pursuant to § 2254(d)(1) “unless the adjudication of the 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.” 28 U.S.C. § 2254(d)(1). In this context, “clearly established federal law
    ‘refers to the holdings, as opposed to the dicta, of [the Supreme] Court’s decisions
    as of the time of the relevant state-court decision.’” Valdez v. Cockrell, 
    274 F.3d 941
    , 946 (5th Cir. 2001) (quoting Terry 
    Williams, 529 U.S. at 412
    , 120 S. Ct. at
    1523).
    Section 2254(d)(2) excepts from the general bar on relief those cases in
    which the adjudication of the claim “resulted in a decision that 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). A reviewing federal court
    presumes that the state court’s factual findings are sound unless the petitioner
    rebuts the “presumption of correctness by clear and convincing evidence.”
    Miller-El v. Dretke, 
    545 U.S. 231
    , 240, 
    125 S. Ct. 2317
    , 2325 (2005); Maldonado
    v. Thaler, 
    625 F.3d 229
    , 236 (5th Cir. 2010). This standard is demanding but not
    insatiable; deference does not by definition preclude relief. 
    Miller-El, 545 U.S. at 240
    , 125 S. Ct. at 2325.
    As the Supreme Court has recently reminded, “If [§ 2254(d)’s] standard is
    difficult to meet, that is because it was meant to be. . . . It preserves authority
    to issue the writ where there is no possibility fairminded jurists could disagree
    that the state court’s decision conflicts with [the Supreme] Court’s precedent.
    It goes no farther.” 
    Harrington, 131 S. Ct. at 786
    (emphasis added) (internal
    quotation marks and citation omitted).
    6
    No. 08-70023
    Petitioner claims that he is entitled to relief under both 28 U.S.C.
    § 2254(d)(1) and 28 U.S.C. § 2254(d)(2); he asserts that the state court’s
    adjudication resulted in a decision contrary to and involving an unreasonable
    application of clearly established federal law and was based on an unreasonable
    determination of the facts in light of the evidence presented in the State Court
    proceeding. We address these claims in turn.
    II.   Section 2254(d)(1) Claims
    A state court’s judgment falls within the “unreasonable application”
    exception of § 2254(d)(1) if the state court correctly identifies the governing
    legal principle from the Supreme Court’s decisions, but unreasonably applies it
    to the facts of the particular case, 
    Busby, 359 F.3d at 713
    , or where it ‘extends
    a legal principle from [Supreme Court] precedent to a new context where it
    should not apply or unreasonably refuses to extend that principle to a new
    context where it should apply.’” LaCaze v. Warden of La. Corr. Inst. for Women,
    
    645 F.3d 728
    , 734 (5th Cir. 2011) (quoting Terry 
    Williams, 529 U.S. at 407
    , 
    413, 120 S. Ct. at 1520
    , 1523). A federal court cannot reverse the denial of habeas
    relief simply by concluding that the state court decision applied clearly
    established federal law erroneously; rather, the court must conclude that such
    application was also unreasonable. See 
    Horn, 508 F.3d at 313
    . In fact, “a
    condition for obtaining habeas corpus from a federal court” is a showing “that the
    state court’s ruling on the claim being presented . . . was so lacking in
    justification that there was an error well understood and comprehended in
    existing law beyond any possibility for fairminded disagreement.” 
    Harrington, 131 S. Ct. at 786
    -87 (emphasis added).
    7
    No. 08-70023
    The first step in determining whether a state court unreasonably applied
    clearly established federal law is to identify the Supreme Court holding that the
    state court supposedly unreasonably applied.       See 
    Valdez, 274 F.3d at 946
    (citation omitted). In the instant case the relevant holding is that of Atkins v.
    Virginia, 
    536 U.S. 304
    , 
    122 S. Ct. 2242
    (2002).
    In Atkins, the Supreme Court held that “death is not a suitable
    punishment for a mentally retarded criminal.” 
    Id. at 321,
    122 S. Ct. at 2252. It
    based this holding on its conclusion that the Eighth Amendment’s meaning is to
    be drawn “from the evolving standards of decency that mark the progress of a
    maturing society.”    
    Id. at 311-12,
    122 S. Ct. at 2247.      To determine what
    “evolving standards of decency” would dictate in this context, the Court turned
    to a consideration of “the judgment of legislatures that have addressed the
    suitability of imposing the death penalty on the mentally retarded[.]” 
    Id. at 313,
    122 S. Ct. at 2247. After considering these judgments, the Court stated that “a
    national consensus” had developed against the imposition of the death penalty
    on the mentally retarded. 
    Id. at 316,
    122 S. Ct. at 2249.
    While it found that there was a national consensus opposing the execution
    of the mentally retarded, the Court acknowledged that there existed
    disagreement “in determining which offenders are in fact retarded.” 
    Id. at 317,
    122 S. Ct. at 2250. In addition, it observed that “[n]ot 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.” 
    Id. Rather than
    formulating a rule for what subset of those who claimed to be mentally retarded
    would be ineligible for the death penalty, the Court left to the states “‘the task
    of developing appropriate ways to enforce the constitutional restriction upon
    8
    No. 08-70023
    [their] execution of sentences.’” 
    Id. (quoting Ford
    v. Wainwright, 
    477 U.S. 399
    ,
    405, 416-17, 
    106 S. Ct. 2595
    , 2605 (1986)); see, e.g., Hill v. Humphrey, ___ F.3d
    ___, 
    2011 WL 5841715
    , at *6, 24 (11th Cir. Nov. 22, 2011) (en banc) (stating that
    the United States Supreme Court “did not provide definitive procedural or
    substantive guides for determining when a person” is mentally retarded and
    holding that the Georgia Supreme Court did not violate any “clearly established”
    federal law by upholding Georgia’s reasonable doubt standard for establishing
    mental retardation).
    Petitioner argues that Atkins requires state courts to apply the clinical
    definitions of mental retardation promulgated by the American Association on
    Mental Retardation (“AAMR”) and American Psychological Assocation (“APA”)
    in evaluating murderers like Petitioner for possible mental retardation.
    Petitioner relies in particular on footnote 22 of Atkins, which noted, in the course
    of recounting the perceived national consensus, that state definitions of mental
    retardation “generally conform . . . to the clinical definitions set forth” by the
    AAMR and APA. 
    Atkins, 536 U.S. at 317
    n.22, 122 S. Ct. at 2250 
    n.22. This
    means the Texas court’s analysis unreasonably applied Atkins’ holding,
    Petitioner concludes, because he believes the state court analysis does not
    conform with the AAMR and APA definitions, under which he contends he is
    retarded.
    To evaluate his claim, we turn to the TCCA’s decision and its grounding
    in Ex parte Briseno, 
    135 S.W.3d 1
    (2005). Petitioner specifically alleges that the
    TCCA’s reliance on the Briseno factors for determining his retardation, rather
    than the AAMR definition, was an unreasonable application of and contrary to
    Atkins. We disagree. It is impossible to conclude that the state court’s analysis
    9
    No. 08-70023
    here, and its reliance on the factors outlined in Briseno, resulted in a decision
    that was based on an unreasonable application of Atkins’s holding.
    Before Atkins, the Texas legislature determined that to be classified as
    retarded, a person must prove three facts by a preponderance of the evidence:
    (a) significantly subaverage general intellectual functioning (proven by showing
    an IQ below 70) and (b) deficits in adaptive behavior that (c) originated during
    the developmental period (before age 18). See T EX. H EALTH & S AFETY C ODE
    § 591.003(13). This definition is almost identical to the AAMR definition of
    mental retardation. The Texas Court of Criminal Appeals adopted the AAMR
    definition of retardation for death penalty cases in 
    Briseno. 135 S.W.3d at 8
    .
    The Briseno court recognized that the AAMR definition was designed for
    the purpose of providing social services, not for the purposes of determining
    whether a person was “so impaired as to fall within the range of mentally
    retarded offenders about whom there is national consensus.” It also recognized
    that determining deficits in adaptive behavior (the second element) was highly
    subjective. Id at 8. To account for these weaknesses in definition, the Briseno
    court listed seven factors to flesh out the AAMR definition to determine whether
    the convict falls within Atkins so as to be protected against the death penalty.
    The court held:
    The adaptive behavior criteria [second element] are
    exceedingly subjective, and undoubtedly experts will be found to
    offer opinions on both sides of the issue in most cases. There are,
    however, some other evidentiary factors which factfinders in the
    criminal trial context might also focus upon in weighing evidence as
    indicative of mental retardation or of a personality disorder:
    • Did those who knew the person best during the
    developmental stage—his family, friends, teachers,
    10
    No. 08-70023
    employers, authorities—think he was mentally
    retarded at that time, and, if so, act in accordance with
    that determination?
    • Has the person formulated plans and carried them
    through or is his conduct impulsive?
    • Does his conduct show leadership or does it show that
    he is led around by others?
    • Is his conduct in response to external stimuli rational
    and appropriate, regardless of whether it is socially
    acceptable?
    • Does he respond coherently, rationally, and on point
    to oral or written questions or do his responses wander
    from subject to subject?
    • Can the person hide facts or lie effectively in his own
    or others’ interests?
    • Putting aside any heinousness or gruesomeness
    surrounding the capital offense, did the commission of
    that offense require forethought, planning, and complex
    execution of purpose?
    135 SW.3d 1, 8 (2005). The Briseno court, in other words, fashioned these
    evidentiary factors as a means “of developing appropriate ways to enforce the
    constitutional restriction” set out in Atkins. And on their face, nothing about
    them contradicts Atkins, as they were developed explicitly to comply with
    Atkins.1
    1
    Indeed, the Briseno factors obviously evoke Atkins’s language which, in turn, evokes
    the AAMR findings. The first Briseno factor, regarding developmental stages, ties to the
    Atkins discussion of the onset of mental retardation before age 
    18. 536 U.S. at 318
    . The
    second and third, regarding impulsive behavior and leadership, tie to the Atkins note that the
    retarded “often act on impulse rather than pursuant to a premeditated plan, and that in group
    settings they are followers rather than leaders.” 
    Id. The fourth,
    regarding rational actions
    and social propriety, ties to the Atkins discussion of “understand[ing] the reactions of others.”
    
    Id. The fifth,
    regarding focused responses to questions, evokes the Atkins discussion of
    “diminished capacities to understand and process information, to communicate . . . .” 
    Id. The sixth,
    concerning the ability to deceive, seems related to Atkins’s mention of “capacit[y] to
    understand and process information, to communicate, to abstract from mistakes and learn
    from experience, to engage in logical reasoning . . . .” 
    Id. And the
    seventh, involving
    11
    No. 08-70023
    This court has never cast doubt on this approach. To the contrary, in
    Clark v. Quarterman, this court held that “it is not ‘clearly established Federal
    law as determined by the Supreme Court of the United States’ that state court
    analysis of subaverage intellectual functioning must precisely track the AAMR’s
    recommended 
    approach.” 457 F.3d at 445
    .         Clark specifically rejected
    Petitioner’s argument that “the Texas courts must apply the approach
    articulated by the [AAMR], which dictates that IQ examiners account for the
    appropriate confidence band.” 
    Id. If Texas
    need not follow AAMR procedures
    when determining subaverage intelligence (a relatively objective determination),
    then it would be senseless to think Texas must follow AAMR procedures when
    determining deficits in adaptive behavior (a far more subjective determination).
    In light of this court’s previous treatment of the Briseno factors, the
    Supreme Court’s broad holding in Atkins, and the irrelevance for the purposes
    of this inquiry of Atkins’ dicta (such as footnote 22), we conclude that the
    application of the Briseno factors, even in the absence of specific employment of
    the AAMR’s methodology for determining deficiencies in adaptive behavior,
    cannot be an “unreasonable application” of Atkins’ broad holding. Atkins clearly
    did not hold—and Petitioner does not even assert that Atkins held—that states
    must employ the AAMR or APA definitions of mental retardation, let alone that
    they must employ the same underlying clinical analysis that the AAMR and
    APA use to determine which patients meet each prong of those organizations’
    definitions; the absence of such a holding is determinative here.
    forethought and planning, seems tied to Atkins’s mention of action “pursuant to a
    premeditated plan.” 
    Id. The Briseno
    factors thus are not arbitrary creations of the Texas
    judiciary but rather carefully constructed considerations that tie directly to Atkins.
    12
    No. 08-70023
    This analysis also disposes of Petitioner’s overlapping argument that the
    state court decision was “contrary to” clearly established federal law. A state
    court’s decision is “contrary to” clearly established federal law if “it relies on
    legal rules that directly conflict with prior holdings of the Supreme Court or if
    it reaches a different conclusion than the Supreme Court on materially
    indistinguishable facts.” 
    Busby, 359 F.3d at 713
    . For the same reasons that
    employment of the Briseno factors to determine adaptive functioning is not an
    unreasonable application of Atkins, the Briseno factors themselves do not
    “contradict” the Supreme Court’s holding in Atkins.         See Terry 
    Williams, 529 U.S. at 405
    , 120 S. Ct. at 1519 (holding state court decision is “contrary”
    when it “applies a rule that contradicts the governing law set forth in our
    cases”). This will come as no surprise, since this court has already concluded
    that the Briseno is not “contrary to” Atkins in precisely this regard. See Woods
    v. Quarterman, 
    493 F.3d 580
    , 587 n.6 (5th Cir. 2007) (“[Petitioner] also argues
    that Ex parte Briseno, relied on by the state habeas court, is contrary to Atkins
    in the way it allows courts to evaluate limitations in adaptive behavior. . . . We
    find nothing in Briseno that is inconsistent with Atkins in this regard.”).
    III.   Section 2254(d)(2) Claims
    With Section 2254(d)(1) unavailable as a means for obtaining federal
    habeas relief, Petitioner must rely on Section 2254(d)(2), but ultimately in vain.
    Section 2254(d)(2) excepts from the section’s general prohibition on habeas relief
    cases where the adjudication of the claim in state court “resulted in a decision
    that 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). The
    TCCA concluded that Petitioner lacked the deficits in adaptive behavior which,
    13
    No. 08-70023
    combined with his subaverage intellectual ability,2 would have yielded the
    characteristics of mental retardation that render him not morally culpable of a
    capital crime. Petitioner, on the other hand, argues that the VABS test is
    dispositive: Under AAMR guidelines, a person with a VABS score of 57 and an
    IQ test of 69 usually would be classified as mildly mentally retarded. Petitioner
    argues that the Briseno factors are not adequate tools to determine whether a
    person is retarded, and that the TCCA’s determination was unreasonable.
    We must consider these claims through AEDPA’s discriminating lens,
    noting that “relief may not be granted unless the decision was based upon an
    unreasonable determination of the facts in light of the evidence presented in the
    State court proceedings. A factual determination made by a state court must be
    rebutted by clear and convincing evidence.” 
    Clark, 457 F.3d at 443
    . “Factual
    determinations by state courts are presumed correct absent clear and convincing
    evidence to the contrary, § 2254(e)(1), and a decision adjudicated on the merits
    in a state court and based on a factual determination will not be overturned on
    factual grounds unless objectively unreasonable in light of the evidence
    presented in the state-court proceeding, § 2254(d)(2).” Miller-El v. Cockrell,
    
    537 U.S. 322
    , 340. As factfinder, the trial court is entitled to deference in
    credibility determinations. Thompson v. Keohane, 
    516 U.S. 99
    , 111, 
    116 S. Ct. 457
    , 465 (1995) (quoting Miller v. Fenton, 
    474 U.S. 104
    , 114, 
    106 S. Ct. 445
    , 452
    (1985)). “The question of whether a defendant suffers from mental retardation
    involves issues of fact, and thus is subject to a presumption of correctness that
    2
    Chester’s IQ tests have resulted in varying numbers, but most of those numbers
    would qualify him as mentally retarded under the AAMR definition if coupled with deficits in
    adaptive behavior.
    14
    No. 08-70023
    must be rebutted by clear and convincing evidence under Section 2254 (e)(1).”
    Maldonado v. Thaler, 
    625 F.3d 229
    , 236 (5th Cir 2010).
    Accordingly, the state courts’ factual determination is presumed correct
    unless Petitioner rebuts it with clear and convincing evidence. The state trial
    court relied on three pieces of evidence to determine that Petitioner had no
    significant deficits in adaptive behavior:
    $     Expert testimony stated that Chester could communicate
    clearly, understood current, topical matters, and understood
    his current legal situation.
    $     Chester’s criminal spree demonstrated the ability to plan,
    avoid detection, and lie.
    $     Chester attempted to escape police custody by lying about the
    location of the hidden murder weapon so that he could grab it.
    Petitioner responds that the Briseno factors and the state’s evidence only
    focus on recent events (the crimes and recent interviews) as opposed to his full
    history. Petitioner presented (and represents in his petition) the following
    evidence:
    $      The Vineland Adaptive Behavior Survey score of 57. Under
    AAMR guidelines, this indicates that Chester has deficits in
    adaptive behavior.
    $     Expert testimony from Dr. Orloff.
    $     Testimony from family members that Chester was always
    “stupid.”
    $     Testimony from school personnel stating that Chester was
    stupid or retarded.
    $     Evidence that Chester enrolled and participated in the
    Mentally Retarded Offenders Program of the Texas
    Department of Criminal Justice.
    15
    No. 08-70023
    The state trial court found, however, that Petitioner’s evidence was
    unpersuasive or not credible. It discounted the family and school administrator’s
    testimony as indicative only of a learning disability, not retardation. Further,
    the court found that the family had an incentive to lie. Similarly, it found that
    Dr. Orloff’s testimony was not credible, due to his insufficient exposure to
    Petitioner and to his lesser credentials. Also, Petitioner’s enrollment in the
    Mentally Retarded Offenders Program was not dispositive because official policy
    allowed non-retarded convicts to participate.
    The Texas Court of Criminal Appeals, while acknowledging that test
    scores alone might have indicated mental retardation, nevertheless was
    compelled to find that the evidence supported the trial court’s finding that
    Petitioner is not mentally retarded.3                   Petitioner has offered no “clear and
    convincing evidence” rebutting the underlying findings or the ultimate finding
    against mental retardation. While a different factfinder might reach a different
    conclusion than the state courts, this court only reviews the proceedings to
    determine whether Petitioner presented clear and convincing evidence that
    rebuts the presumption that the state trial court’s determination was correct.
    §§ 2254(d)(2), (e)(1). Petitioner failed to do so. Proceedings at the state trial
    court were a battle between experts with additional testimony and evidence that
    3
    Petitioner and the dissent repeatedly claim that the state courts relied “solely” on the Briseno
    factors. The dissent uses this device to assert that the TCCA’s decision is “contrary” to Atkins legally.
    But the TCCA opinion (a) states the proper test, (b) states how the AAMR guidelines are informed by
    the Briseno factors, and (c) corrects the state habeas court to confirm that Petitioner’s diagnostic tests
    alone usually indicated a diagnosis of mild mental retardation. The court clearly took the test results
    into account but found them overborne by evidence and credibility determinations of the trial court. This
    is not “sole reliance” on improper factors but a faithful application of the principle, acknowledged in
    Atkins itself, that the adaptive functioning component of mental retardation is complex. The dissent
    would, contrary to Atkins, either prevent the state court from applying its expertise here, or confine the
    state “solely” to diagnostic test results in debatable cases.
    16
    No. 08-70023
    was inconclusive and invited credibility testing. It is not this court’s place to
    second-guess the court’s credibility determinations.
    This analysis conclusively establishes that § 2254(d)(2) avails Petitioner
    nothing. But we wish to note a few striking facts from the record that highlight
    the deficiency of petitioner’s claim that the state courts’ factual findings
    regarding deficiencies in adaptive behavior were “unreasonable.” Petitioner
    carefully cased the house of his victims, located the telephone box, cut the
    telephone wires, entered through an unlocked door (presumably to avoid the
    noise that would accompany breaking in), disguised himself in a ski mask, and
    raped/sodomized the two women inside using all the precautions one might
    expect to see from a clever criminal.
    After murdering the girls’ uncle, Petitioner fired his gun into the locked
    doors of the victim’s car, apparently reasoning that shooting a lock would break
    it and cause it to fail. This was hardly the work of a person with diminished
    mental capacity; it was problem-solving in response to a crisis.
    Atkins explains:
    [C]linical definitions of mental retardation require not only
    subaverage intellectual functioning, but also significant limitations
    in adaptive skills such as communication, self-care, and self-
    direction that became manifest before age 18. Mentally retarded
    persons frequently know the difference between right and wrong
    and are competent to stand trial. Because of their impairments,
    however, by definition they have diminished capacities to
    understand and process information, to communicate, to abstract
    from mistakes and learn from experience, to engage in logical
    reasoning, to control impulses, and to understand the reactions of
    others. There is no evidence that they are more likely to engage in
    criminal conduct than others, but there is abundant evidence that
    they often act on impulse rather than pursuant to a premeditated
    17
    No. 08-70023
    plan, and that in group settings they are followers rather than
    
    leaders. 536 U.S. at 318
    , 122 S. Ct. at 2250 (emphasis added). It seems obvious that
    Petitioner did not act on an impulse, but rather “pursu[ed] a premeditated plan,”
    acting of his own volition rather than as a “follower[].”               
    Id. Indeed, he
    masterminded a sophisticated break-in and dealt with a crisis as it developed.
    Nothing about this crime suggests Petitioner had difficulties “process[ing]
    information” or “engag[ing] in logical reasoning.” Id.4
    Of course, the Petitioner’s burden here is much higher than simply
    convincing us that Petitioner is not mentally retarded under Atkins. He has to
    show by clear and convincing evidence that the state court’s determination was
    unreasonable; he falls far short of this burden.
    CONCLUSION
    Because the TCCA’s decision was not contrary to or an unreasonable
    application of clearly established federal law, and because it was not based on
    an unreasonable factual determination in light of the evidence before it, we
    AFFIRM the district court’s denial of habeas relief.
    4
    Petitioner’s other crimes, fully documented in the state court record and in the
    TCCA’s opinion, further illustrate his cunning criminal calculations. As an example, the
    murder of John Sepeda – to which Petitioner confessed – similarly involved the cutting of
    telephone lines leading into a residence’s call box. And before murdering Cheryl DeLeon,
    Petitioner unscrewed the lightbulb in the outdoor security light. Evidently, Petitioner was
    able “to abstract from mistakes and learn from experience . . . .” Atkins, 536 U.S. at 
    318, 122 S. Ct. at 2250
    .
    18
    No. 08-70023
    DENNIS, Circuit Judge, dissenting.
    I respectfully dissent because the majority opinion affirms a Texas Court
    of Criminal Appeals (TCCA) death penalty judgment that is contrary to the
    federal law clearly established by Atkins v. Virginia, 
    536 U.S. 304
    (2002): When
    Atkins banned the execution of mentally retarded offenders, it defined mental
    retardation as generally conforming to the three-part clinical definitions set
    forth by the American Association on Mental Retardation (AAMR) and the
    American Psychiatric Association (APA), which were quoted by the Court in
    Atkins. In the present case, the TCCA, instead of applying the “adaptive skill
    areas” part of that definition, 
    id. at 308
    n.3, applied its own substantively
    contrary state law, known as the “Briseno factors,” in erroneously deciding that
    Elroy Chester failed to prove that he is mentally retarded. For this reason, I
    would vacate the federal district court’s judgment affirming the TCCA’s
    judgment and remand the case to the federal district court for further
    proceedings applying the entire correct clinical definition of mental retardation
    as required by Atkins.
    In Atkins, the Supreme Court held that the Eighth Amendment’s
    prohibition of “cruel and unusual punishments” bars the execution of mentally
    retarded offenders. The Court reasoned that: (1) there is a national consensus
    among state legislatures and Congress that the execution of mentally retarded
    offenders is excessive punishment, 
    id. at 314-16;
    (2) the statutory definitions of
    “mental retardation” used by states in that national consensus are not identical,
    but generally conform to, the clinical definitions of “mental retardation” set
    forth by the AAMR and APA, 
    id. at 317
    n.22; and (3) the Supreme Court’s
    independent evaluation of the issue revealed no reason for the Court to disagree
    19
    No. 08-70023
    with the national legislative consensus, 
    id. at 321.
    Based on this rationale, the
    Atkins Court concluded that the Eighth Amendment “‘places a substantive
    restriction on the State’s power to take the life’ of a mentally retarded offender,”
    
    id. (quoting Ford
    v. Wainwright, 
    477 U.S. 399
    , 405 (1986)), and that this
    constitutional restriction protects individuals who “fall within the range of
    mentally retarded offenders about whom there is a national consensus,” 
    id. at 317
    . Further, Atkins made plain that the AAMR and APA “clinical definitions
    of mental retardation require not only subaverage intellectual functioning, but
    also significant limitations in adaptive skills such as communication, self-care,
    and self-direction that became manifest before age 18.” 
    Id. at 318.1
    Thus, in
    deciding whether a person is mentally retarded and therefore exempt from
    execution under the Eighth Amendment, a state court must apply each of the
    three prongs — subaverage intellectual functioning; adaptive functioning
    limitations; and onset prior to age eighteen — of a definition that generally
    conforms to the AAMR and APA clinical definitions of “mental retardation.”
    In Atkins, the Court also concluded that “[n]ot 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 with regard to insanity, ‘we leave to the State[s]
    the task of developing appropriate ways to enforce the constitutional restriction
    1
    Authorities have used the terms “adaptive functioning,” “adaptive behavior,” and
    “adaptive skills” to refer to this element of mental retardation. See Am. Ass’n on Mental
    Retardation, Mental Retardation: Definition, Classification, and Systems of Supports 1 (10th
    ed. 2002) [hereinafter AAMR-10] (referring to “limitations . . . in adaptive behavior as
    expressed in conceptual, social, and practical adaptive skills”); Am. Psychiatric Ass’n,
    Diagnostic and Statistical Manual of Mental Disorders 41 (4th ed., text rev. 2000) [hereinafter
    DSM-IV-TR] (referring to “limitations in adaptive functioning in at least two of [eleven] skill
    areas”); Am. Ass’n on Mental Retardation, Mental Retardation: Definition, Classification, and
    Systems of Supports 5 (9th ed. 1992) [hereinafter AAMR-9] (referring to “limitations in two or
    more of [ten] adaptive skill areas”). Neither the state nor Chester argues that these
    terminological differences have any effect on the issues in this appeal. Accordingly, this
    opinion refers to adaptive functioning, adaptive behavior, and adaptive skills interchangeably.
    20
    No. 08-70023
    upon [their] execution of sentences.’” 
    Id. at 317
    (alterations in original) (citation
    omitted) (quoting 
    Ford, 477 U.S. at 416-17
    ). In so doing, the Ford Court made
    clear that when “the Eighth Amendment bars execution of a category of
    defendants defined by their mental state[,] [t]he bounds of that category are
    necessarily governed by federal constitutional law.” 
    Ford, 477 U.S. at 419
    (Powell, J., concurring in part and concurring in the judgment, but speaking for
    the majority on this point).2 Thus, by closely following Ford, Atkins signals
    clearly that federal constitutional law governs the bounds of the category of
    mentally retarded individuals who are exempt from execution, although the
    states, within the confines of due process, may devise procedures to govern
    mental retardation determinations.
    Our en banc court and panels have adopted this understanding of Atkins.
    See Moore v. Quarterman, 
    533 F.3d 338
    , 341 (5th Cir. 2008) (en banc) (“Atkins
    specifically reserved to the states the adoption of procedures to implement its
    new constitutional rule . . . .” (emphasis added)); Wiley v. Epps, 
    625 F.3d 199
    ,
    207 (5th Cir. 2010) (“[E]ven though Atkins left to the states the job of
    implementing procedures for determining who is mentally retarded, ‘it was
    decided against the backdrop of the Supreme Court’s and lower court’s due
    process jurisprudence.’” (emphasis added) (quoting Rivera v. Quarterman, 
    505 F.3d 349
    , 358 (5th Cir. 2007))). Accordingly, the states retain substantial
    discretion to create appropriate procedures, but they may not substantively
    redefine mental retardation so as to permit the execution of those who “fall
    within the range of mentally retarded offenders about whom there is a national
    consensus.” 
    Atkins, 536 U.S. at 317
    .
    2
    See Panetti v. Quarterman, 
    551 U.S. 930
    , 949 (2007) (“Justice Powell’s opinion
    constitutes ‘clearly established’ law for purposes of [28 U.S.C.] § 2254 and sets the minimum
    procedures a State must provide to a prisoner raising a Ford-based competency claim.”)
    21
    No. 08-70023
    In Atkins, the Supreme Court quoted and referred to the AAMR definition
    of mental retardation as follows: “Mental retardation refers to substantial
    limitations in present functioning. It is characterized by [(1)] significantly
    subaverage intellectual functioning, [(2)] 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 work[; and
    (3)] Mental retardation manifests before age 
    18.” 536 U.S. at 309
    .3
    The Texas habeas trial court, in considering Chester’s habeas petition, did
    not apply the second element of the AAMR definition to determine if Chester had
    “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 work.”
    Instead, the trial court applied the “Briseno factors,” a series of questions
    originally suggested by the TCCA in Ex parte Briseno, 
    135 S.W.3d 1
    (Tex. Crim.
    App. 2004), which the TCCA itself has described as being “non-diagnostic
    criteria.” Ex parte Van Alstyne, 
    239 S.W.3d 815
    , 820 (Tex. Crim. App. 2007).
    Although the factors were initially conceived of as “evidentiary factors which
    factfinders . . . might also focus upon in weighing evidence as indicative of
    mental retardation or of a personality disorder,” 
    Briseno, 135 S.W.3d at 8
    , the
    TCCA in the present case used the Briseno factors as a substantive part of its
    mental retardation definition, instead of the second prong of the AAMR
    definition (the AAMR clinical adaptive skills criteria) to determine that Chester
    had not proved he had adaptive skills deficits, and, therefore, that Chester failed
    3
    In Atkins, the Court also quoted and referred to the similar APA clinical definition of
    mental retardation. Because the Texas courts have adverted only to the AAMR clinical
    definition, and the two clinical definitions are substantively the same, I set forth and refer
    here only to the AAMR clinical definition of mental retardation.
    22
    No. 08-70023
    to prove he is mentally retarded. See Ex parte Chester, No. AP-75037, 
    2007 WL 602607
    (Tex. Crim. App. Feb. 28, 2007) (unpublished).
    Chester introduced evidence that he scored under 70 in 4 of the 5 full-scale
    IQ tests that he has taken since the age of seven years, and scored 57 on the
    Vineland Adaptive Behavior Survey (VABS), a clinical adaptive functioning test.
    His evidence showed he has been unable to live or work independently, and his
    experts and lay witnesses related that he suffered from mild mental retardation
    and was deficient in several adaptive behavioral areas. The state habeas trial
    court, which gave no reason for applying the Briseno factors to the exclusion of
    the AAMR adaptive skills criteria and the VABS test results, found that Chester
    failed to disprove any of the Briseno factors, was therefore not limited in
    adaptive functioning, and thus not mentally retarded for this reason alone. See
    Chester, 
    2007 WL 602607
    , at *4. The TCCA affirmed, approving of the trial
    court’s use of the Briseno factors to the exclusion of clinical adaptive skills
    criteria to define mental retardation. 
    Id. at *9.
    The U.S. District Court denied
    federal habeas relief, on the ground that Chester’s application failed under the
    seventh Briseno factor alone. Chester v. Quarterman, No. 5:05cv29, 
    2008 WL 1924245
    , at *7 (E.D. Tex. Apr. 29, 2008) (unpublished).
    The TCCA’s decision was contrary to the federal law that was clearly
    established by the Supreme Court in Atkins. Under Atkins, state courts must
    apply a mental retardation definition that generally conforms to all three parts
    of the clinical AAMR or APA definitions. The TCCA’s unique nondiagnostic
    Briseno factors are more constricted than, unrelated to, and substantively
    contrary to the adaptive deficits criteria identified in the second prongs of the
    AAMR and APA clinical definitions of mental retardation. Exclusively applying
    the Briseno factors to assess the substantive adaptive skills prong of the mental
    retardation definition inevitably leads to anomalous and unreliable results,
    including the execution of offenders who should be classified as mentally
    23
    No. 08-70023
    retarded and shielded from execution under Atkins and the comprehensive
    clinical definitions quoted therein. In other words, by affirming the Texas courts’
    erroneous use of the Briseno factors in place of the adaptive skills prong of the
    substantive three-part rule defining mental retardation, the majority allows
    those state courts to circumvent the constitutional rule of Atkins and to use their
    more constricted definition of mental retardation to exclude substantial numbers
    of mentally retarded offenders from protection from execution under the Eighth
    Amendment.4 Because the decisions of the TCCA and the federal district court
    are based on the same error of clear constitutional law, the judgment of the
    federal district court should be set aside and the case should be remanded to it
    for further proceedings generally conforming to the clinical definitions of mental
    retardation as required by Atkins.
    I.
    The petitioner, Elroy Chester, robbed and raped two young women at
    gunpoint in their home. When the women’s uncle unexpectedly arrived at the
    house, Chester shot and killed him. He pleaded guilty to the crime of capital
    murder and was sentenced to death by a Texas jury in 1998. His conviction and
    sentence were affirmed on direct appeal. Chester then sought post-conviction
    relief at the state and federal levels on the grounds that he could not be executed
    because he is mentally retarded.
    Chester’s federal habeas petition was pending in 2002 when the Supreme
    Court held in Atkins that the Eighth Amendment forbids the execution of
    4
    At least one study suggests that Texas may be favorably resolving far fewer Atkins
    claims than the national average. As of 2011, of the 81 Texas petitioners whose Atkins
    collateral review claims have been resolved, only 14 (17% of the total) have been successful.
    This “is significantly lower than the ‘national average’ success rate of thirty-eight percent
    identified in a 2008 study of states that had resolved Atkins claims.” Peggy M. Tobolowsky,
    A Different Path Taken: Texas Capital Offenders’ Post-Atkins Claims of Mental Retardation,
    39 Hastings Const. L.Q. 1, 71 & nn. 203-04, 373-74 (2011) (citing John H. Blume et al., An
    Empirical Look at Atkins v. Virginia and its Application in Capital Cases, 
    76 Tenn. L
    . Rev.
    625, 628-29, 637 (2009)).
    24
    No. 08-70023
    mentally retarded offenders. Consequently, Chester’s petition was dismissed
    without prejudice to allow him to renew his claim for state post-conviction relief
    on the basis of Atkins. Chester v. Cockrell, No. 02-41152, 62 F. App’x 556 (5th
    Cir. Feb. 26, 2003).
    The TCCA granted Chester leave to file a successive state habeas petition
    and remanded his case to the state trial court for further proceedings. The trial
    court held an evidentiary hearing on the Atkins claim. In order to prove that he
    was mentally retarded, under Atkins, 
    536 U.S. 304
    , and Briseno, 
    135 S.W.3d 1
    ,5
    Chester was required to show by a preponderance of the evidence that he had (1)
    significantly subaverage general intellectual functioning and (2) related
    limitations in adaptive functioning, (3) the onset of which had occurred before
    Chester reached age 18. 
    Briseno, 135 S.W.3d at 7
    . Chester introduced
    substantial evidence of his mental retardation, including full-scale IQ scores of
    5
    In Ex parte Briseno, the TCCA determined how, in the absence of guidance from the
    state legislature, Texas courts would procedurally “‘enforce the constitutional restriction’”
    imposed by Atkins. 
    Briseno, 135 S.W.3d at 5
    (quoting 
    Atkins, 536 U.S. at 317
    ). The Briseno
    court held that Atkins claims in habeas corpus applications would be decided by judges rather
    than juries, 
    id. at 11,
    and that the defendant would bear the burden of proof to establish
    mental retardation by a preponderance of the evidence, 
    id. at 12.
             In addition to establishing these procedural specifications, the Briseno court described
    “some other evidentiary factors which factfinders in the criminal trial context might also focus
    upon in weighing evidence as indicative of mental retardation or of a personality disorder.” 
    Id. at 8.
    They include: (1) “Did those who knew the person best during the developmental stage
    . . . think he was mentally retarded at that time, and, if so, act in accordance with that
    determination; (2) “Has the person formulated plans and carried them through or is his
    conduct impulsive?”; (3) “Does his conduct show leadership or does it show that he is led
    around by others?”; (4) “Is his conduct in response to external stimuli rational and appropriate,
    regardless of whether it is socially acceptable?”; (5) “Does he respond coherently, rationally,
    and on point to oral or written questions or do his responses wander from subject to subject?”;
    (6) “Can the person hide facts or lie effectively in his own or others’ interests?”; (7) “Putting
    aside any heinousness or gruesomeness surrounding the capital offense, did the commission
    of that offense require forethought, planning, and complex execution of purpose?” 
    Id. at 8-9.
             As will be discussed more fully below, the Briseno court did not initially present these
    factors as a substitute or alternative definition of mental retardation, but only as additional
    factors which a court “might also” take into consideration. The Briseno factors differ
    substantially from the adaptive skill areas identified by the AAMR and APA in the clinical
    definitions of mental retardation. See infra Sections IV, VI.A.
    25
    No. 08-70023
    69 at age seven, 59 at age twelve, 77 at age thirteen, 69 at age eighteen, and 66
    at age twenty-nine and a score of 57 on VABS, a standardized test of adaptive
    functioning. The Texas Department of Criminal Justice administered one of
    these IQ tests – on which Chester scored a 69 – and the VABS test in 1987, when
    Chester was eighteen years old. The State’s own expert testified that a person
    with those test scores would be correctly diagnosed as mentally retarded. In
    addition, an expert retained by Chester testified that he was indeed mentally
    retarded. Chester also supplied other evidence tending to show that he suffers
    from limitations in adaptive functioning. He presented evidence that he was
    placed in special education early in schooling and admitted into the prison
    Mentally Retarded Offenders Program (MROP) at approximately age eighteen;
    achievement testing in prison placed him at third grade levels or below. Two of
    his sisters testified regarding his adaptive behavior deficits, including his
    inability to live or work independently. A special education teacher testified
    regarding his limited abilities at school. One expert diagnosed Chester as
    mentally retarded based on a review of his records, interviews with Chester, and
    observation of the State expert’s interview with him. Another expert classified
    him as mildly mentally retarded based on a review of his MROP records.
    Chester asserted that he demonstrated deficits regarding the broader
    conceptual and practical adaptive skill areas, as well as the specific skill areas
    of communication, work, functional academics, self-direction, and community
    use. The trial court, adopting the entirety of the prosecution’s proposed findings
    of fact and conclusions of law, concluded that Chester had failed to carry his
    burden of proof as to either of the first two elements of mental retardation:
    significantly subaverage general intellectual functioning and related limitations
    in adaptive functioning. The trial court found that Chester failed to prove that
    he had adaptive skill deficits but it did not apply the clinical AAMR criteria to
    make this finding. Instead, it applied the Briseno “evidentiary factors” and
    26
    No. 08-70023
    concluded that, under the Briseno factors, Chester was not limited in adaptive
    functioning and therefore failed to satisfy the adaptive functioning prong of the
    tripartite clinical definitions of mental retardation. He therefore was found to
    be not mentally retarded. If the trial court had applied the clinical adaptive
    functioning criteria instead, Chester’s evidence arguably would have shown he
    satisfied this prong as well as the other two and that he is mentally retarded.
    On appeal, the TCCA partly overruled the trial court’s findings and
    conclusions. Chester, 
    2007 WL 602607
    . The TCCA held that Chester “has met his
    burden in regard to demonstrating significant limitations in intellectual
    functioning,” 
    id. at *3,
    and that “there is no dispute as to the third part of the
    test, that the evidence in favor of a finding of mental retardation occurred and
    was recorded before the applicant reached the age of eighteen,” 
    id. at *2.
    Thus,
    the TCCA held that Chester had satisfied the first and third prongs of the
    definition of mental retardation. However, the TCCA denied habeas relief
    because it concluded that Chester had not “[s]hown [s]ignificant [d]eficits in
    [a]daptive [b]ehavior” as required by the second prong, 
    id. at *4,
    and he had
    therefore not carried the burden of showing that he was mentally retarded. In
    reaching this conclusion, the TCCA did not consider the AAMR’s or APA’s
    clinical definitions of mental retardation, but relied exclusively on the factors
    that had previously been presented in Briseno as merely “some other evidentiary
    factors which factfinders in the criminal trial context might also focus upon in
    weighing evidence as indicative of mental retardation or of a personality
    disorder,” 
    Briseno, 135 S.W.3d at 8
    . See Chester, 
    2007 WL 602607
    , at *4-5.
    Chester then filed another federal habeas petition. In that proceeding, the
    state did not dispute that the evidence of his mental deficits developed before he
    was eighteen years old or “that Chester suffers from significantly sub-average
    intellectual functioning.” Chester, 
    2008 WL 1924245
    , at *2. But the district court
    departed even further than the state courts from the Atkins clinical definitions
    27
    No. 08-70023
    of mental retardation, expressly holding that a finding as to just one of the seven
    Briseno factors was a sufficient basis for denying an Atkins claim: “[A]n
    affirmative finding as to the seventh and final Briseno evidentiary factor is
    sufficient by itself to uphold a denial of relief in a habeas corpus proceeding.” 
    Id. at *7.6
           Thus, the district court held that the TCCA’s “rejection of [Chester’s]
    mental retardation claim is neither inconsistent with, nor the result of an
    unreasonable application of, clearly established federal law,” and denied habeas
    relief. Id.7
    Chester now appeals from the district court’s order denying habeas relief.
    II.
    “In a habeas corpus appeal, we review the district court’s findings of fact
    for clear error and review its conclusions of law de novo, applying the same
    standard of review to the state court’s decision as the district court.” Beazley v.
    Johnson, 
    242 F.3d 248
    , 255 (5th Cir. 2001) (quoting Thompson v. Cain, 
    161 F.3d 802
    , 805 (5th Cir. 1998)) (internal quotation marks omitted).8 I conclude that
    6
    The seventh Briseno evidentiary factor is as follows: “Putting aside any heinousness
    or gruesomeness surrounding the capital offense, did the commission of that offense require
    forethought, planning, and complex execution of purpose?” 
    Briseno, 135 S.W.3d at 8
    -9.
    7
    However, the district court granted Chester a certificate of appealability as to three
    issues, the first two of which are as follows:
    1. The state courts’ determination that Mr. Chester is not mentally retarded is
    unreasonable in light of the evidence presented in the state court and violates
    the Eighth Amendment by permitting the execution of a mentally retarded
    defendant.
    2. As a way to assess significantly subaverage adaptive functioning, the Briseno
    factors have no basis in the scientific literature and conflict with the accepted
    definitions of mental retardation recognized and relied on in Atkins v. Virginia,
    making the state courts’ exclusive reliance on the Briseno factors an
    unreasonable application of federal law clearly established in Atkins and
    violating the Eighth Amendment by permitting the execution of a mentally
    retarded defendant.
    8
    Because the TCCA was the last state court to address Chester’s arguments, we review
    the decision of that court. See Wood v. Quarterman, 
    491 F.3d 196
    , 202 (5th Cir. 2007) (focusing
    on whether “the last reasoned state court decision” was “contrary to, [or] an unreasonable
    application of, federal law”); see also Watson v. Anglin, 
    560 F.3d 687
    , 690 (7th Cir. 2009) (“We
    28
    No. 08-70023
    Chester has shown that his habeas petition should be granted under the
    “contrary to” clause of AEDPA, 28 U.S.C. § 2254(d)(1). Therefore, I need not
    consider whether he also satisfies the unreasonable application” clause of
    AEDPA, 28 U.S.C. § 2254(d)(1), and need not review the district court’s findings
    of fact for clear error.
    “Under the Antiterrorism and Effective Death Penalty Act (AEDPA), a
    federal court may not grant § 2254 habeas relief on any ground previously
    disposed of on the merits by a state court unless the state decision ‘was contrary
    to, or involved an unreasonable application of, clearly established [f]ederal law,
    as determined by the Supreme Court of the United States,’ or ‘was based on an
    unreasonable determination of the facts in light of the evidence presented in the
    [s]tate court proceeding.’” Geiger v. Cain, 
    540 F.3d 303
    , 306-07 (5th Cir. 2008)
    (alterations in original) (quoting 28 U.S.C. § 2254(d)(1)-(2)); see also Woods v.
    Quarterman, 
    493 F.3d 580
    , 584 (5th Cir. 2007). “A state court decision is
    contrary to clearly established federal law if it ‘applies a rule that contradicts the
    governing law set forth in [Supreme Court] cases,’ or if the state court confronts
    a set of facts that are materially indistinguishable from a decision of [the
    Supreme Court] and nevertheless arrives at a result different from [the Court’s]
    precedent.’ A state court decision involves an unreasonable application of clearly
    established federal law if the state court ‘correctly identifies the governing legal
    rule but applies it unreasonably to the facts of a particular prisoner’s case . . . .’”
    Williams v. Quarterman, 
    551 F.3d 352
    , 358 (5th Cir. 2008) (alterations in
    review the decision of the last state court to address [the petitioner’s] arguments.”); Mark v.
    Ault, 
    498 F.3d 775
    , 783 (8th Cir. 2007) (“[W]e apply the AEDPA standard to . . . the ‘last
    reasoned decision’ of the state courts.” (quoting Ylst v. Nunnemaker, 
    501 U.S. 797
    , 804
    (1991))); Joseph v. Coyle, 
    469 F.3d 441
    , 450 (6th Cir. 2006) (“[T]he decision we review is that
    of ‘the last state court to issue a reasoned opinion on the issue.’” (quoting Payne v. Bell, 
    418 F.3d 644
    , 660 (6th Cir. 2005))); Barker v. Fleming, 
    423 F.3d 1085
    , 1091 (9th Cir. 2005) (“When
    more than one state court has adjudicated a claim, we analyze the last reasoned decision.”).
    29
    No. 08-70023
    original) (citations omitted) (quoting Williams v. Taylor, 
    529 U.S. 362
    , 405-08
    (2000)).
    III.
    In Atkins, the Supreme Court early in its opinion set forth in full the
    generally accepted clinical definitions of mental retardation:
    The American Association on Mental Retardation (AAMR)
    defines mental retardation 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 work. Mental retardation
    manifests before age 18.” Mental Retardation: Definition,
    Classification, and Systems of Supports 5 (9th ed. 1992).
    The American Psychiatric Association’s [(APA)] definition is
    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.”
    Diagnostic and Statistical Manual of Mental Disorders 41 (4th ed.
    2000). “Mild” mental retardation is typically used to describe people
    with an IQ level of 50-55 to approximately 70. 
    Id., at 42-43.
    Atkins, 536 U.S. at 308 
    n.3. The Court then surveyed developments in state and
    federal law that showed a growing nationwide consensus that mentally retarded
    defendants should not be executed. See 
    id. at 313-16.
    Beginning with a Georgia
    law enacted in 1988, the Court counted eighteen states, along with the federal
    government, which had enacted legislation prohibiting the execution of mentally
    retarded defendants. See 
    id. at 313-15.
    Furthermore, the Court observed that
    30
    No. 08-70023
    “even in those States that allow the execution of mentally retarded offenders, the
    practice is uncommon[:] . . . only five [states] have executed offenders possessing
    a known IQ less than 70” since 1989. 
    Id. at 316.
          The Court therefore concluded that “a national consensus has developed
    against” the execution of mentally retarded defendants. 
    Id. “To the
    extent there
    is serious disagreement about the execution of mentally retarded offenders, it is
    in determining which offenders are in fact retarded. . . . 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.” 
    Id. at 317
    . The Court noted that “[t]he [states’] statutory definitions of mental
    retardation are not identical, but generally conform to the clinical definitions”
    promulgated by the AAMR and the APA. 
    Id. at 317
    n.22. Thus, the Court’s
    holding that “a national consensus has developed,” 
    id. at 316,
    was based on
    statutes which employed “definitions of mental retardation” that “generally
    conform to the clinical definitions” quoted above, 
    id. at 317
    n.22.
    As an additional step in its reasoning, the Court undertook an
    “independent evaluation of the issue.” 
    Id. at 321.
    In this step, the Court reasoned
    that “by definition,” people with mental retardation have certain characteristics
    that make their execution cruel and unusual. 
    Id. at 318.
    These characteristics
    include “diminished capacities to understand and process information, to
    communicate, to abstract from mistakes and learn from experience, to engage
    in logical reasoning, to control impulses, and to understand the reactions of
    others.” 
    Id. Because of
    these characteristics, “executing the mentally retarded
    will not measurably further the goal of deterrence,” 
    id. at 320,
    and “the lesser
    culpability of the mentally retarded offender . . . does not merit that form of
    retribution.” 
    Id. at 19.
    Moreover, mentally retarded defendants “face a special
    risk of wrongful execution” because of “the possibility of false confessions, [and]
    the lesser ability of mentally retarded defendants to make a persuasive showing
    31
    No. 08-70023
    of mitigation.” 
    Id. at 320-21.
    Therefore, the Court concluded, there was “no
    reason to disagree with the judgment of ‘the legislatures that have recently
    addressed the matter’ and concluded that death is not a suitable punishment for
    a mentally retarded criminal.” 
    Id. (quoting Enmund
    v. Florida, 
    458 U.S. 782
    ,
    801 (1982)).
    In short, the holding of Atkins is that the Eighth Amendment prohibits the
    execution of individuals who are “so impaired as to fall within the range of
    mentally retarded offenders about whom there is a national consensus.” 
    Id. at 317
    . And the Court described the parameters of that “national consensus” as
    “generally conform[ing] to the clinical definitions” of mental retardation used by
    the AAMR and APA. 
    Id. at 317
    & n.22.
    The Court refrained from setting forth procedures for determining whether
    a particular defendant is “so impaired as to fall within the range of mentally
    retarded offenders about whom there is a national consensus.” 
    Id. at 317
    .
    Rather, it declared, “we leave to the States the task of developing appropriate
    ways to enforce the constitutional restriction upon their execution of sentences.”
    
    Id. (quoting Ford
    , 477 U.S. at 405) (brackets and internal quotation marks
    omitted).
    The Atkins Court noted that this was the same “approach” that the Court
    had previously followed “in Ford v. Wainwright with regard to 
    insanity.” 536 U.S. at 317
    . We have previously observed that “Ford is instructive” in Atkins
    cases “because of the similarity of the competency and mental retardation issues:
    both decisions affirmatively limit the class of persons who are death penalty
    eligible.” 
    Rivera, 505 F.3d at 358
    . The Court’s opinions in Atkins and Ford both
    expressly announced “that the Constitution ‘places a substantive restriction on
    the State’s power to take the life’” of certain offenders. 
    Atkins, 536 U.S. at 321
    (quoting 
    Ford, 477 U.S. at 405
    ); see also 
    Panetti, 551 U.S. at 957
    (same).
    32
    No. 08-70023
    In Ford, Justice Powell’s controlling concurring opinion 9 explained that
    when “the Eighth Amendment bars execution of a category of defendants defined
    by their mental state[,] [t]he bounds of that category are necessarily governed
    by federal constitutional 
    law.” 477 U.S. at 419
    . Further, the Panetti Court
    explained that Ford “broadly identif[ied]” a “substantive standard for
    incompetency”; applying this substantive standard, the Panetti Court “reject[ed]
    the standard followed by the Court of Appeals” as being inconsistent with 
    Ford. 551 U.S. at 960
    . Thus, it is clear under both Ford and Panetti that the definition
    of incompetency to be executed is a matter of federal substantive constitutional
    law. Because Atkins expressly adopted Ford’s approach by announcing “a
    substantive 
    restriction,” 536 U.S. at 321
    , while giving states procedural room to
    “develop[] appropriate ways to enforce” that restriction, 
    id. at 317
    , it follows that
    under Atkins, too, the substantive definition of mental retardation for Eighth
    Amendment purposes is a matter of federal constitutional law.
    Atkins identified a substantive standard for mental retardation by
    announcing that states may not execute offenders who are “so impaired as to fall
    within the range of mentally retarded offenders about whom there is a national
    consensus.” 
    Atkins, 536 U.S. at 317
    . The Court explained that the “national
    consensus” was based on state-law definitions of mental retardation that
    “generally conform to the clinical definitions” in the AAMR-9 and DSM-IV-TR,
    which the Court quoted in full in its opinion. 
    Id. at 308
    n.3, 317 & n.22.
    Therefore, in order to “appropriate[ly] . . . enforce the constitutional restriction”
    imposed by Atkins, 
    id. at 317
    (quoting 
    Ford, 477 U.S. at 416
    ), states must apply
    definitions of mental retardation that “generally conform to the clinical
    definitions,” 
    id. at 317
    n.22.10
    9
    See 
    Panetti, 551 U.S. at 949
    (“Justice Powell’s opinion [in Ford] constitutes ‘clearly
    established law’ for purposes of [28 U.S.C.] § 2254 . . . .”).
    10
    See Pruitt v. State, 
    834 N.E.2d 90
    , 108 (Ind. 2005) (plurality opinion) (“[T]he Eighth
    Amendment must have the same content in all United States jurisdictions. . . . Because Atkins
    33
    No. 08-70023
    IV.
    In 2004, the Texas Court of Criminal Appeals issued an opinion declaring
    how the Texas courts would “enforce the constitutional restriction” under Atkins.
    
    Briseno, 135 S.W.3d at 5
    (quoting 
    Atkins, 536 U.S. at 317
    ). The court observed
    that it had “previously employed the definitions of ‘mental retardation’ set out
    by the AAMR, and that contained in section 591.003(13) of the Texas Health and
    Safety Code. Under the AAMR definition, mental retardation is a disability
    characterized by: (1) ‘significantly subaverage’ general intellectual functioning;
    (2) accompanied by ‘related’ limitations in adaptive functioning; (3) the onset of
    which occurs prior to the age of 18. As noted above, the definition under the
    Texas Health and Safety Code is similar . . . .” 
    Id. at 7
    (footnotes omitted) (citing,
    inter alia, AAMR-9, supra note 1, at 5).11 Accordingly, the court concluded that
    “[u]ntil the Texas Legislature provides an alternate statutory definition of
    ‘mental retardation’ for use in capital sentencing, we will follow the AAMR or
    section 591.003(13) criteria in addressing Atkins mental retardation claims.” 
    Id. at 8.
            However, the Briseno court expressed some concern with the “adaptive
    behavior criteria” in the AAMR definition,12 which it considered to be
    explains that state statutes that provided the ‘national consensus’ against the execution of the
    mentally retarded ‘generally conform’ to the AAMR or DSM-IV definitions, we conclude that
    Atkins requires at least general conformity with those definitions, but allows considerable
    latitude within that range. . . . [W]e think that the prohibition of the execution of the mentally
    retarded must have some content. There may be some flexibility in determining mental
    retardation, but we think that if a state’s definition of mental retardation were completely at
    odds with definitions accepted by those with expertise in the field the definition would not
    satisfy the prohibition.”).
    11
    Section 591.003(13) of the Texas Health and Safety Code states: “‘mental retardation’
    means significantly subaverage general intellectual functioning that is concurrent with deficits
    in adaptive behavior and originates during the developmental period.”
    12
    As previously noted, the AAMR’s 1992 definition of mental retardation, as quoted by
    the Supreme Court in Atkins, includes an “adaptive functioning” prong, which requires
    “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 work.” 
    Atkins, 536 U.S. at 308
    n.3 (quoting AAMR-9, supra note 1, at
    5). The AAMR issued a revised definition of mental retardation in 2002, see 
    AAMR-10, supra
    34
    No. 08-70023
    “exceedingly subjective.” 
    Id. at 8.
    For this reason, the court identified “some
    other evidentiary factors which factfinders in the criminal trial context might
    also focus upon in weighing evidence as indicative of mental retardation or of a
    personality disorder.” Id.13 Those additional factors are as follows:
    • Did those who knew the person best during the developmental
    stage — his family, friends, teachers, employers, authorities —
    think he was mentally retarded at that time, and, if so, act in
    accordance with that determination?
    • Has the person formulated plans and carried them through or is
    his conduct impulsive?
    • Does his conduct show leadership or does it show that he is led
    around by others?
    • Is his conduct in response to external stimuli rational and
    appropriate, regardless of whether it is socially acceptable?
    • Does he respond coherently, rationally, and on point to oral or
    written questions or do his responses wander from subject to
    subject?
    • Can the person hide facts or lie effectively in his own or others’
    interests?
    note 1, but the differences between the AAMR’s 1992 and 2002 criteria for adaptive
    functioning or adaptive behavior are not relevant to this appeal.
    13
    The Briseno court may have mistakenly assumed that a defendant cannot suffer
    from both mental retardation and a personality disorder, when in fact individuals often suffer
    both from mental retardation and personality disorders. “[T]he scientific and clinical
    definitions emphasize that individuals with mental retardation often have mental disorders
    as well. No reasonable clinician would have determined that [a defendant] did not have mental
    retardation merely because the evidence also supported a diagnosis of antisocial personality
    disorder.” John H. Blume et al., Of Atkins and Men: Deviations from Clinical Definitions of
    Mental Retardation in Death Penalty Cases, 18 Cornell J.L. & Pub. Pol’y 689, 692 (2009). The
    AAMR has authoritatively explained that “[t]he types of mental health disorders are the same
    in people with and people without mental retardation.” 
    AAMR-10, supra
    note 1, at 172. “The
    prevalence of mental health disorders among individuals with mental retardation is difficult
    to estimate due to problems in sampling and diagnosis. In general, mental health disorders
    are much more prevalent in this population compared to the general population.” 
    Id. Thus, an
    offender might well be correctly diagnosed with both mental retardation and a personality
    disorder. See Lambert v. State, 
    126 P.3d 646
    , 659 (Okla. Crim. App. 2005) (“Mental retardation
    and mental illness are separate issues. It is possible to be mentally retarded and mentally
    ill.”).
    35
    No. 08-70023
    • Putting aside any heinousness or gruesomeness surrounding the
    capital offense, did the commission of that offense require
    forethought, planning, and complex execution of purpose?
    
    Id. at 8-9.
    Although the TCCA identifies the Briseno factors as “adaptive
    functioning” criteria, the factors bear no resemblance to the AAMR or APA
    adaptive functioning criteria. The Briseno court cited no sources or authorities
    for the proposition that these “other evidentiary factors” are an accurate or
    useful way to tell whether a person is genuinely mentally retarded; thus, the
    factors appear to be wholly the TCCA’s own creation. These factors are “non-
    diagnostic,” Van 
    Alstyne, 239 S.W.3d at 820
    , and based on the judges’
    impressions and assumptions about mental retardation. See Blume, supra note
    13, at 712. The court gave no explanation of how the factors are any less
    “subjective” than the criteria for adaptive functioning in the AAMR’s definition
    of mental retardation, and they are not based on or drawn from the adaptive
    functioning skill areas identified by the AAMR or the APA. See 
    Atkins, 536 U.S. at 308
    n.3; see also supra note 1.14
    After setting forth these evidentiary factors, the TCCA went on to
    determine the procedural means by which Atkins claims in state habeas
    petitions would be resolved. The court decided that “Atkins does not require a
    jury determination of mental retardation in a post-conviction proceeding,” 
    id. at 9,
    and that “[t]he defendant bears the burden of proof, by a preponderance of the
    evidence, to establish that he is mentally retarded,” 
    id. at 12
    (bold face removed).
    The court then concluded that the petitioner in that case, Jose Garcia Briseño,
    14
    It is also unclear how the Briseno factors could be used as an independent, conclusive
    way to determine whether a person has significant limitations in adaptive functioning. The
    AAMR-9, DSM-IV-TR, and AAMR-10 definitions of mental retardation clearly specify how
    their adaptive functioning criteria are to be used: a person fulfills the criteria if he or she has
    significant limitations in two of ten, or two of eleven, or one of three, areas. By contrast, the
    Briseno factors do not indicate whether a defendant must negate one factor, or a majority of
    them, or all seven, or if some factors have more weight than others.
    36
    No. 08-70023
    had failed to prove by a preponderance of the evidence that he was mentally
    retarded. See 
    id. at 14-18.
           In summary, as relevant here, the Briseno court first determined that
    Texas courts “w[ould] follow the AAMR or section 591.003(13) criteria in
    addressing Atkins mental retardation claims,” and then mentioned seven “other
    evidentiary factors which factfinders . . . might also focus upon” in determining
    whether a defendant has the limitations in adaptive behavior that are required
    for a finding of mental retardation. 
    Id. at 8.
                                                  V.
    In the present case, the TCCA held that Chester fulfilled two of the three
    requirements of mental retardation: significantly subaverage intellectual
    functioning and onset before age 18.15 It is undisputed in this appeal that
    Chester meets those requirements. Whether Chester is mentally retarded
    therefore depends on whether he meets the one remaining requirement:
    significant limitations in adaptive functioning. In the state habeas proceedings,
    Chester presented a substantial amount of evidence that tended to prove that
    he does have significant limitations in adaptive functioning, under the standard
    clinical definitions of mental retardation to which the national consensus
    generally conforms, see 
    Atkins, 536 U.S. at 317
    & n.22. However, the TCCA
    concluded that Chester is not mentally retarded — a conclusion which was based
    entirely and exclusively on the TCCA’s application of the Briseno evidentiary
    factors. Chester, 
    2007 WL 602607
    , at *4-5, *9.
    Chester provided the state courts with factual evidence and expert
    testimony indicating that he has significant limitations in adaptive functioning
    15
    The state trial court, on habeas, adopted the prosecution’s proposed findings of fact
    and conclusions of law in their entirety and thereby held that Chester did not have
    significantly subaverage intellectual functioning. However, the TCCA observed that “the trial
    court’s findings on the applicant’s [IQ] test scores were in conflict with the record” and
    concluded that Chester “has met his burden in regard to demonstrating significant limitations
    in intellectual functioning.” Chester, 
    2007 WL 602607
    , at *2-3.
    37
    No. 08-70023
    as defined by the AAMR and APA criteria.16 Notably, he received a score of 57
    on the VABS test, which is a clinical method of assessing a person’s level of
    adaptive functioning for the purpose of diagnosing mental retardation.17 The
    TCCA observed that “even the State’s expert witness acknowledged that a
    person with a Vineland score of 57, combined with an IQ score of 69 as measured
    at the same time, would be correctly diagnosed as mildly mentally retarded.”
    Chester, 
    2007 WL 602607
    , at *3. These two scores were obtained in 1987 by the
    Texas Department of Criminal Justice, when Chester was eighteen years old. He
    was admitted to the department’s Mentally Retarded Offender Program at that
    time. 
    Id. That was
    eleven years before Chester committed the murder for which
    16
    Chester also argues that the evidence shows that he is mentally retarded under the
    revised definition promulgated by the AAMR’s tenth edition in 2002. See generally 
    AAMR-10, supra
    note 1. The questions raised in this appeal do not turn on any differences between the
    AAMR’s 2002 definition and the earlier definitions that the Supreme Court quoted in Atkins.
    Thus, we have no occasion to consider what the result should be if a defendant were to show
    that he was retarded under one clinical definition but not under another one. Cf., e.g., Wiley
    
    v, 625 F.3d at 216
    n.13 (noting that expert witnesses in that case “indicated that their
    diagnoses of [the defendant] were the same under both” the AAMR’s 1992 and 2002 definitions
    of the adaptive behavior prong); In re Hearn, 
    418 F.3d 444
    , 445 (5th Cir. 2005) (citing the
    AAMR-10 in support of a general definition of mental retardation: “Mental retardation is a
    disability characterized by three criteria: significant limitation in intellectual functioning,
    significant limitation in adaptive behavior and functioning, and onset of these limitations
    before the age of 18”); United States v. Hardy, 
    762 F. Supp. 2d 849
    , 879 (E.D. La. 2010) (“While
    these differences in definition deserve note, they are ultimately of no consequence to the
    Court’s task. Just as in Wiley, . . . the court need not decide which is preferable or correct,
    because the differences between them are mostly theoretical. Both the APA and AAMR direct
    clinicians to the same standardized measures of adaptive behavior, such as the Vineland
    Adaptive Behavior Scales-II . . . .”).
    17
    Courts, including the TCCA, have often considered VABS test scores to be a valid way
    of assessing the adaptive functioning prong of mental retardation. See, e.g., Van 
    Alstyne, 239 S.W.3d at 820
    n.12 (“The Vineland Adaptive Behavior Test is one of the recognized
    standardized scales for measuring adaptive deficits.” (citing Ex parte Blue, 
    230 S.W.3d 151
    ,
    165 n.55 (Tex. Crim. App. 2007))).
    Moreover, the AAMR favors the use of standardized tests, such as the VABS, as a way
    to diagnose mental retardation: “For the diagnosis of mental retardation, significant
    limitations in adaptive behavior should be established through the use of standardized
    measures normed on the general population, including people with disabilities and people
    without disabilities. On these standardized measures, significant limitations in adaptive
    behavior are operationally defined as performance that is at least two standard deviations
    below the mean . . . .” 
    AAMR-10, supra
    note 1, at 76 (emphasis added).
    38
    No. 08-70023
    he was sentenced to death, and fifteen years before the Supreme Court decided
    Atkins; thus, Chester could not have been faking mental retardation to avoid the
    death penalty. The TCCA’s opinion gave no specific reason for disbelieving or
    disregarding Chester’s VABS score of 57. Neither has the State of Texas given
    us any reason why the score would not be reliable.
    Chester also presented substantial evidence of limitations in at least four
    out of the AAMR’s ten “adaptive skill areas”: communication, home living,
    functional academics, and work. 
    Atkins, 536 U.S. at 308
    n.3 (quoting AAMR-9,
    supra note 1, at 5).18 For instance, there was evidence that while growing up,
    Chester had severe communication difficulties: he spoke in jumbled sentences
    with misused words and a small vocabulary. His school diagnosed him with a
    “serious communicative handicap” and provided therapy. Other children called
    him “stupid” and “retarded.” He attended special education classes from third
    through twelfth grades. All his classes were taught to him at his own academic
    level, which was never higher than third grade. As an adult, when out of jail,
    Chester never lived independently; never had a driver’s license or a bank
    account; held only menial jobs; could not read or write well enough to fill out a
    job application; and could not shop or cook by himself. At eighteen years of age
    he could read “only small words” and could not name the months of the year,
    according to the Texas Department of Criminal Justice’s assessment which
    resulted in his being admitted to the MROP.19
    18
    The AAMR and APA definitions of mental retardation require that a person have
    limitations in only two adaptive skill areas. 
    Atkins, 536 U.S. at 308
    n.3.
    19
    There are disputes about the significance of some of the evidence in the record. For
    instance, Dr. Edward Gripon, the state’s mental retardation expert, testified that the correct
    diagnosis for someone with an IQ score of 69 and a VABS score of 57 is mental retardation.
    Yet he also testified that he did not think Chester was mentally retarded.
    The state emphasizes that although Chester was placed in the MROP, he was officially
    classified as having “borderline intellectual functioning” rather than mental retardation.
    However, Dr. Henry Orloff, a psychologist who was the MROP’s director at the time, testified
    that there was no basis for the diagnosis of borderline intellectual functioning, and that the
    erroneous diagnosis had been allowed to stand because at that time, it made no practical
    39
    No. 08-70023
    Despite Chester’s VABS test score of 57 — which the state’s own expert
    witness testified was low enough to require a diagnosis of mental retardation —
    and despite his substantial evidence of adaptive functioning limitations in at
    least four of the AAMR skill areas, the state courts relied exclusively on the
    Briseno factors to determine that Chester did not meet this requirement of
    mental retardation. Thus, the state courts did not use the Briseno factors in the
    limited way in which the TCCA’s Briseno opinion announced that they would be
    used — as “other evidentiary factors” that a court “might also focus upon” in
    addition to the AAMR’s clinical 
    definition. 135 S.W.3d at 8
    (emphases added).
    The TCCA in Briseno stated that it would apply the AAMR’s 1992
    definition of mental retardation, which includes adaptive functioning criteria,
    in Atkins cases. 
    Id. The adaptive
    functioning prong of the AAMR’s 1992
    definition of mental retardation, as quoted in Atkins, is satisfied by a finding of
    “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 work.” 
    Atkins, 536 U.S. at 308
    n.3 (quoting AAMR-9, supra note 1, at 5) (quotation marks
    omitted). Similarly, the APA has stated that mentally retarded individuals will
    have “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,
    difference.
    The state also emphasizes that in school, Chester was categorized as being learning
    disabled rather than mentally retarded. However, Chester counters that a diagnosis of
    learning disability would be simply invalid in light of his consistently low IQ test results, since
    a person with a learning disability by definition has a discrepancy between IQ and academic
    achievement. The DSM-IV-TR explains: “Learning Disorders are diagnosed when the
    individual’s achievement on individually administered, standardized tests in reading,
    mathematics, or written expression is substantially below that expected for age, schooling, and
    level of intelligence.” DSM-IV-TR, supra note 1, at 49 (emphasis added). By contrast, “In
    Mental Retardation, learning difficulties are commensurate with general impairment in
    intellectual functioning.” 
    Id. at 51
    (emphasis added).
    40
    No. 08-70023
    work, leisure, health, and safety.” 
    Id. (quoting DSM-IV-TR,
    supra note 1, at 41
    (quotation marks omitted). Yet the TCCA in this case made no attempt
    whatsoever to determine whether Chester has significant limitations in two or
    more of those areas of adaptive functioning.20 The state trial court likewise made
    no such attempt.
    Instead, the TCCA and the state trial court both treated their findings
    under the Briseno factors as if they were a sufficient basis, standing alone, for
    determining whether a person has significant limitations in adaptive
    functioning. The courts did not employ — nor did they even mention — any of
    the clinical definitions or criteria for adaptive functioning limitations. The trial
    court stated: “This Court’s review of evidentiary factors relating to adaptive
    behavior suggested relevant by the Court of Criminal Appeals in Ex parte
    Briseno weigh conclusively against Applicant’s argument that he is mentally
    retarded.” State v. Chester, No. 76044-B, slip op. at 25 (Crim. Dist. Ct. Jefferson
    Cnty., Tex. July 26, 2004). The TCCA stated: “The trial court’s findings
    addressed all seven evidentiary factors listed in Briseno, and noted carefully how
    the applicant had failed to persuade the trial court on each one.” Chester, 
    2007 WL 602607
    , at *4. The TCCA, in effect, dispensed with any measurement of
    “adaptive functioning” as it is conceived of by the clinical mental retardation
    definitions and the adaptive functioning criteria contained therein.
    The federal district court, in denying Chester habeas relief, likewise made
    no attempt to determine whether Chester has significant limitations in adaptive
    functioning according to a rule generally conforming to the clinical definition of
    mental retardation. The federal district court relied entirely on the seventh
    20
    Nor did the TCCA make any attempt to apply any other clinical criteria for assessing
    adaptive functioning, such as the AAMR’s 2002 definition, which requires “performance that
    is at least two standard deviations below the mean of either (a) one of the following three types
    of adaptive behavior: conceptual, social, or practical, or (b) an overall score on a standardized
    measure of conceptual, social, and practical skills.” 
    AAMR-10, supra
    note 1, at 14.
    41
    No. 08-70023
    Briseno factor, and nothing else, as the adaptive functioning test: “an affirmative
    finding as to the seventh and final Briseno evidentiary factor is sufficient by
    itself to uphold a denial of relief in a habeas corpus proceeding.” Chester, 
    2008 WL 1924245
    , at *7. Thus, not only did the federal district court disregard the
    AAMR and APA clinical criteria that were used by the Atkins Court to define
    mental retardation, but it disregarded six of the seven Briseno factors as well.
    VI.
    A.
    The TCCA’s decision in the present case is contrary to the clear holding of
    the Court in Atkins. “A state court decision is contrary to clearly established
    federal law if it ‘applies a rule that contradicts the governing law set forth in
    [Supreme Court] cases . . . .’” Williams v. 
    Quarterman, 551 F.3d at 358
    (first
    alteration in original) (quoting Williams v. 
    Taylor, 529 U.S. at 405
    ). The TCCA
    applied a rule of decision using the Briseno factors as its exclusive basis for
    holding that Chester does not have significant limitations in adaptive
    functioning and that he is therefore not mentally retarded for Eighth
    Amendment purposes. By so holding, the TCCA adopted and applied a rule of
    decision that the Briseno “other evidentiary factors,” standing alone, can be used
    to determine that an offender does not have significant limitations in adaptive
    functioning and is therefore not mentally retarded, even when the offender has
    presented strong evidence that he satisfies all the AAMR or APA clinical criteria
    for mental retardation.
    The TCCA’s rule of decision is contrary to Atkins because, as explained
    above, Atkins held that the Eighth Amendment imposes a “substantive
    
    restriction,” 536 U.S. at 321
    , which prevents states from executing offenders who
    are “so impaired as to fall within the range of mentally retarded offenders about
    whom there is a national consensus,” 
    id. at 317
    . In order to “appropriate[ly] . . .
    enforce th[is] constitutional restriction,” states must apply definitions of mental
    42
    No. 08-70023
    retardation for Eighth Amendment purposes that reflect the “national
    consensus” by “generally conform[ing] to the [AAMR and APA] clinical
    definitions” of mental retardation. 
    Id. at 317
    & n.22. The rule applied by the
    TCCA in this case involved a radical departure from general conformity with
    those clinical definitions of mental retardation. It redefined the adaptive
    functioning element in such a way that it clearly contradicts and fails to carry
    out Atkins’s mandate to protect from execution all offenders who fall within the
    national consensus’s understanding of mental retardation that generally
    conforms to the AAMR and APA definitions.
    The Briseno evidentiary factors, standing alone, cannot be used to
    accurately determine that a person does not have significant limitations in
    adaptive functioning according to the national consensus’s understanding of
    mental retardation that the Atkins Court identified. This is because the Briseno
    evidentiary factors are substantively very different from, and ask different
    questions than, the AAMR and APA criteria. For instance, the Briseno factors
    do not consider, and therefore cannot determine, whether a person has
    significant limitations in the adaptive skill areas of self-care, home living,
    community use, health and safety, functional academics, leisure, or work. The
    AAMR-9 and APA criteria or precepts generally conforming to them require only
    that a person must have significant limitations in two out of ten or eleven
    adaptive skill areas (as well as showing significantly subaverage intellectual
    functioning and onset before age 18). The AAMR and APA have noted that
    mentally retarded individuals have strength areas and that the most
    appropriate way to identify adaptive functioning deficits is to focus on the
    individual’s limitations. See 
    AAMR-10, supra
    note 1, at 8 (“[P]eople with mental
    retardation are complex human beings who likely have certain gifts as well as
    limitations . . . . These may include strengths in social or physical capabilities,
    strengths in some adaptive skill areas, or strengths in one aspect of an adaptive
    43
    No. 08-70023
    skill in which they otherwise show an overall limitation.”); Blume et al., supra
    note 13, at 706, 710 (quoting 
    AAMR-10, supra
    note 1, at 8); see also Holladay v.
    Allen, 
    555 F.3d 1346
    , 1363 (11th Cir. 2009) (“Individuals with mental
    retardation have strengths and weaknesses, like all individuals. Indeed, the
    criteria for diagnosis recognizes this by requiring a showing of deficits in only
    two of ten identified areas of adaptive functioning.”); 
    Lambert, 126 P.3d at 651
    (“Unless a defendant’s evidence of particular limitations is specifically
    contradicted by evidence that he does not have those limitations, then the
    defendant’s burden is met no matter what evidence the State might offer that
    he has no deficits in other skill areas.”).21
    The Briseno factors, used exclusive of the clinical definitions, operate in
    a significantly different manner. As in this case, if the factfinder concludes that
    the petitioner met one of the Briseno factors even in a limited period of time or
    situation, the factfinder may then overlook the petitioner’s limitations and
    conclude that the petitioner is not mentally retarded. Thus, a person could easily
    21
    The AAMR’s 2002 definition of mental retardation incorporates the following
    explanation:
    Assumption 3: “Within an individual, limitations often coexist with strengths.”
    This means that people with mental retardation are complex human beings who
    likely have certain gifts as well as limitations. Like all people, they often do
    some things better than other things. Individuals may have capabilities and
    strengths that are independent of their mental retardation. These may include
    strengths in social or physical capabilities, strengths in some adaptive skill
    areas, or strengths in one aspect of an adaptive skill in which they otherwise
    show an overall limitation.
    
    AAMR-10, supra
    note 1, at 8. In accordance with this principle, the Oklahoma Court of
    Criminal Appeals, has explained that evidence regarding an offender’s criminal activity is
    relevant for Atkins purposes only insofar as it tends to show that the offender does or does not
    have limitations in the areas specified by the clinical definitions: “Lambert was required to
    show . . . that he had limitations in adaptive functioning in two of nine areas . . . . None of the
    evidence of criminal activity went to any of Lambert’s claims of adaptive function limitations.
    Thus, strictly speaking, none of it was relevant to disprove those claims.” 
    Lambert, 126 P.3d at 656
    .
    The Briseno evidentiary factors, because they focus heavily on isolated instances of a
    person’s behavior, by design are not meant to indicate whether a person meets the standard
    clinical criteria for mental retardation, which assess an individual’s limitations in adaptive
    functioning based on his or her typical behavior.
    44
    No. 08-70023
    have significant limitations in two or more of these areas and yet be determined
    not to be mentally retarded by a court that relied exclusively on the Briseno
    evidentiary factors. Exclusive reliance on the Briseno factors renders evidence
    of significant limitations meaningless, and is directly contrary to the clinical
    definitions.
    Moreover, at least some of the Briseno factors are concerned with aspects
    of a person’s behavior that bear no relation to mental retardation as defined by
    the AAMR and APA. The second Briseno evidentiary factor (“Has the person
    formulated plans and carried them through or is his conduct impulsive?”)
    describes impulsivity as a sign of mental retardation, but the DSM-IV-TR flatly
    contradicts this: “Some individuals with Mental Retardation are passive, placid,
    and dependent, whereas others can be aggressive and impulsive.” DSM-IV-TR,
    supra note 1, at 44. The fourth and fifth Briseno evidentiary factors (“Is his
    conduct in response to external stimuli rational and appropriate, regardless of
    whether it is socially acceptable? Does he respond coherently, rationally, and on
    point to oral and written questions or do his responses wander from subject to
    subject?”) treat rationality and coherent communication as being inconsistent
    with mental retardation, but the clinical definitions do not indicate that
    mentally retarded people cannot communicate or behave rationally. On the
    contrary, the DSM-IV-TR states that people with mild mental retardation —
    who are “the largest segment (about 85%) of those with the disorder” —
    “typically develop social and communication skills” and “usually achieve social
    and vocational skills adequate for minimum self-support.” DSM-IV-TR, supra
    note 1, at 43.
    Finally, the Briseno evidentiary factors also substantially depart from
    clinical definitions of mental retardation because they focus on isolated instances
    of a person’s behavior rather than on a person’s typical, day-to-day level of
    adaptive functioning. The seventh Briseno factor especially focuses on how the
    45
    No. 08-70023
    underlying capital crime was committed. This focus on isolated events – and
    especially on extraordinary events, like a situation in which a person commits
    murder — runs directly contrary to the clinical definitions’ emphasis on day-to-
    day functioning and on the fact that mentally retarded people, like anyone else,
    have strengths as well as limitations, in particular circumstances as well as in
    different skill areas. See 
    Holladay, 555 F.3d at 1363
    (criticizing the state’s expert
    for her “predominant focus on [the offender’s] actions surrounding the crime,”
    which “suggest[ed] that she did not recognize [that people with mental
    retardation have strengths as well as weaknesses]”); see also Caroline
    Everington & J. Gregory Olley, Implications of Atkins v. Virginia: Issues in
    Defining and Diagnosing Mental Retardation, 8 J. Forensic Psychol. Prac., no.
    1, 2008, at 1,     11 (“[P]erhaps most important, adaptive behavior is the
    individual’s typical performance in his/her community setting. The details of the
    crime cannot be considered to be a sample of typical behavior.”).
    As the Supreme Court explained in Williams v. 
    Taylor, 529 U.S. at 405
    (O’Connor, J., concurring in part and concurring in the judgment, and speaking
    for the court on this point), “a state-court decision is contrary to this Court’s
    precedent if the state court arrives at a conclusion opposite to that reached by
    this Court on a question of law” or “if the state court confronts facts that are
    materially indistinguishable from a relevant Supreme Court precedent and
    arrives at a result opposite to ours.” Further elaborating, the Court stated:
    The word “contrary” is commonly understood to mean “diametrically
    different,” “opposite in character or nature,” or “mutually opposed.”
    Webster’s Third New International Dictionary 495 (1976). The text
    of § 2254(d)(1) therefore suggests that the state court’s decision
    must be substantially different from the relevant precedent of this
    Court. . . . A state-court decision will certainly be contrary to our
    clearly established precedent if the state court applies a rule that
    contradicts the governing law set forth in our cases.
    
    Id. (emphasis added).
    46
    No. 08-70023
    Then, the Court gave two examples to clarify its meaning. First, it
    explained that:
    If a state court were to reject a prisoner’s claim of ineffective
    assistance of counsel on the grounds that the prisoner had not
    established by a preponderance of the evidence that the result of his
    criminal proceeding would have been different, that decision would
    be “diametrically different,” “opposite in character or nature,” and
    “mutually opposed” to our clearly established precedent because we
    held in Strickland that the prisoner need only demonstrate a
    “reasonable probability that . . . the result of the proceeding would
    have been different.”
    
    Id. at 405-06
    (quoting Strickland v. Washington, 
    466 U.S. 668
    , 694 (1984)). The
    Court then provided an example of when a state law is not “contrary to” a clearly
    established federal law:
    [A] run-of-the-mill state-court decision applying the correct legal
    rule from our cases to the facts of a prisoner’s case would not fit
    comfortably within § 2254(d)(1)’s “contrary to” clause. Assume, for
    exam ple, that a state-court decision on a prisoner’s
    ineffective-assistance claim correctly identifies Strickland as the
    controlling legal authority and, applying that framework, rejects the
    prisoner’s claim. Quite clearly, the state-court decision would be in
    accord with our decision in Strickland as to the legal prerequisites
    for establishing an ineffective-assistance claim, even assuming the
    federal court considering the prisoner’s habeas application might
    reach a different result applying the Strickland framework itself. It
    is difficult, however, to describe such a run-of-the-mill state-court
    decision as “diametrically different” from, “opposite in character or
    nature” from, or “mutually opposed” to Strickland, our clearly
    established precedent.
    
    Id. 406. Applying
    the Court’s precepts to the present case, it is clear that the TCCA
    has arrived at a decision that is contrary to Atkins because it applied a rule that
    contradicts the governing law set forth in Atkins. Similarly to the first example
    given in Williams v. Taylor, the TCCA rejected Chester’s Atkins claim on the
    grounds that he had not established his limitations in adaptive functioning by
    47
    No. 08-70023
    proving he was so limited or deficient according to the state-law Briseno factors.
    That decision is “diametrically different,” “opposite in character or nature,” and
    “mutually opposed” to the Court’s clearly established precedent because the
    Court held in Atkins that Chester need only demonstrate that he has adaptive
    functioning deficits according to a definition that generally conforms to the
    AAMR or APA clinical definitions. The Briseno factors do not generally conform
    to, and indeed are “substantially different” from, either the AAMR or APA
    adaptive functioning criteria. See Williams v. 
    Taylor, 529 U.S. at 405
    .
    In other words, this is not a run-of-the-mill state-court decision in which
    the state court correctly identified the clinical adaptive functioning prong of
    Atkins’s clinical definition of mental retardation and, applying that framework,
    rejected the prisoner’s claim. Instead, the TCCA in this case disregarded the
    adaptive functioning framework recognized by the Court in Atkins and applied
    the state-court-created Briseno factors, which are “diametrically different,”
    “opposite in character or nature,” and “mutually opposed” to a definition that
    generally conforms to the clinical criteria recognized by the Court in Atkins for
    defining mental retardation. Specifically, the TCCA’s decision was contrary to
    Atkins itself, where the Court held that a defendant may demonstrate his
    adaptive functioning deficits by showing limitations in specific skill areas that
    generally conform to the AAMR or APA clinical mental retardation definitions.
    Thus, because the Briseno evidentiary factors are substantively different
    from and contrary to the clinical and diagnostic approaches to determining
    deficits in adaptive functioning, when they are used as the sole measure of a
    person’s adaptive functioning, rather than concordantly with clinically
    standardized test results and professionally accepted criteria, they cannot
    accurately determine whether a person is mentally retarded in accordance with
    the national consensus’s understanding of mental retardation that the Supreme
    Court identified in Atkins.
    48
    No. 08-70023
    B.
    In addition to being contrary to Atkins, the TCCA decision in this case did
    not follow its own earlier opinion in Briseno in which it had stated that it would
    apply the AAMR definition of mental retardation or the similar Texas Health
    Code § 591.003(13) definition. 
    Briseno, 135 S.W.3d at 7
    -8. The Briseno court
    mentioned some “other evidentiary factors” that a court “might also focus upon,”
    
    id. at 8
    (emphases added), but it did not suggest that those factors could be used
    as a substitute for substantive clinical criteria in determining whether an
    offender has significant limitations in adaptive functioning. In this case, the
    TCCA disregarded the Atkins second prong clinical criteria altogether and used
    Briseno’s “other evidentiary factors” as its sole basis for determining that
    Chester does not have significant limitations in adaptive functioning. The
    district court took this substantive definition change a step further and held that
    an affirmative finding of the seventh Briseno factor alone can serve as the sole
    basis for affirming the TCCA.
    The three-judge dissent in Lizcano v. State, No. AP-75879, 
    2010 WL 1817772
    (Tex. Crim. App. May 5, 2010) (Price, J., concurring and dissenting)
    (unpublished), made the point forcefully that the TCCA majority, in using or
    allowing the use of the Briseno factors to the exclusion of clinical diagnostic
    criteria to determine whether a petitioner has satisfied the second prong of the
    tripartite definition of mental retardation, contradicts both Atkins and Briseno.
    In Lizcano, as in Chester, the factfinder used the Briseno factors to the exclusion
    of clinical diagnostic criteria to reject the petitioner’s mental retardation claim
    and to affirm his death sentence. The dissent acknowledged that there may be
    “fodder” in the Briseno decision to support the Lizcano majority’s argument that
    the jury is not “bound by the diagnostic criteria,” 
    id. at *34,
    but then correctly
    argued that such a belief runs contrary to established federal law: “Atkins
    adopted a categorical prohibition. It was founded upon the Supreme Court’s
    49
    No. 08-70023
    ratification of the prevalent legislative judgment that it is inappropriate to
    execute mentally retarded offenders. That legislative judgment comprehended
    mental retardation in essentially the same ‘clinical’ terms as the AAMR’s and
    APA’s diagnostic criteria.” 
    Id. at *35.
          The Lizcano dissent argued that the TCCA was not “justif[ied] [in its]
    apparent grant of latitude to fact-finders in Texas to adjust the clinical criteria
    for adaptive deficits to conform to their own normative judgments with respect
    to which mentally retarded offenders are deserving of the death penalty and
    which are not.” 
    Id. In failing
    to “anchor the fact-finder’s decision on the specific
    diagnostic criteria,” 
    id., the majority
    acted unconstitutionally: “Even if the
    Supreme Court in Atkins ‘did not mandate the application of a particular mental
    health standard for mental retardation, . . . it did recognize the significance of
    professional standards and framed the constitutional prohibition in medical
    rather than legal terms.’ It would be anomalous to allow the fiat of a fact-finder
    to undermine the essentially diagnostic character of the inquiry. We should not
    . . . permit a [fact-finder] capriciously to deviate from the specific diagnostic
    criteria in order to conform to its own normative, unnecessarily subjective, and
    certainly unscientific judgment regarding who deserves the death penalty.” 
    Id. (first alteration
    in original) (footnotes omitted).
    In summary, in order to determine whether Chester is mentally retarded
    and   protected   from   execution    under    Atkins,   the   state   courts   were
    constitutionally obligated to employ a definition of mental retardation that
    would identify and protect the class of offenders covered by Atkins’s “substantive
    restriction on the State’s power to take [a] life” — namely, those offenders who
    are “so impaired as to fall within the range of offenders about whom there is a
    national consensus.” 
    Atkins, 536 U.S. at 317
    , 321. However, in their adjudication
    of Chester’s claim, the state courts transformed the Briseno evidentiary factors
    into a stand-alone substantive test for the adaptive functioning prong of the
    50
    No. 08-70023
    mental retardation definition, a test that does not “generally conform to the
    clinical definitions,” 
    id. at 317
    n.22, and hence cannot accurately determine
    whether an offender falls within the class that is protected by Atkins. The state
    courts did this even though Chester presented standardized test scores and other
    evidence tending to show that he satisfied the clinical criteria for adaptive
    functioning limitations (as well as the other two prongs of mental retardation,
    which he has undisputedly established). Therefore, the state courts’ decision that
    Chester is not mentally retarded was “contrary to” Atkins, under 28 U.S.C. §
    2254(d)(1), because the state court applied a rule that contradicted the governing
    law clearly set forth in Atkins.
    VII.
    The issue presented by this case is not whether a state or federal court
    must strictly apply the AAMR or APA clinical definitions of mental retardation
    in deciding Atkins claims — as the majority suggests — but rather whether a
    court must apply a definition that generally conforms to those clinical
    definitions, or whether a court can disregard or depart freely from them and
    make up its own unscientific and non-clinical definition of mental retardation
    that contradicts the definitions to which the national consensus generally
    conforms. Atkins requires that states apply a definition that “generally
    conforms” to the AAMR and APA clinical definitions and diagnostic assessments
    of mental retardation, which the national consensus has embraced. In this case,
    the TCCA utilized parts of the tripartite definition of mental retardation, but its
    definition of the adaptive functioning prong does not generally conform to the
    national consensus’s definition of this prong and in fact departs substantially
    from the nationally accepted criteria for determining whether a petitioner has
    adaptive functioning deficits.
    The majority erroneously concludes that the Briseno factors provide a
    constitutionally acceptable means of limiting the class of defendants who are
    51
    No. 08-70023
    death eligible, and that Chester’s claim must fail. There is a vast distance
    between a holding requiring strict adherence to a clinical definition and a
    holding that would allow states to develop their own definitions of mental
    retardation without regard for the clinical definitions or the national consensus.
    While the former is not required by Atkins, the latter clearly falls outside
    Atkins’s constitutional bounds because Atkins requires that the state’s definition
    “generally conform” to the clinical definitions that the national consensus relied
    upon in narrowing the class of death eligible defendants to exclude mentally
    retarded defendants.
    The Atkins holding clearly prohibits the execution of mentally retarded
    defendants. Although as in Ford, the Supreme Court left to the states the task
    of enforcing this restriction, 
    Atkins, 536 U.S. at 317
    , “[t]he bounds of that
    category are necessarily governed by federal constitutional law.” 
    Ford, 477 U.S. at 419
    (Powell, J., concurring in part and concurring in the judgment, and
    speaking for the majority on this point). The prohibition becomes meaningless
    unless it is moored to a generally agreed upon definition of “mental retardation.”
    Yet this is what the majority does: it releases the definition from its moorings.
    The TCCA should not be permitted to circumvent Atkins’s constitutional
    prohibition by totally supplanting the definition of adaptive functioning that,
    prior to Briseno, had been utilized by Texas courts and which “generally
    conform[ed]” both with the AAMR clinical definition and with the national
    consensus that had developed around the AAMR and APA definitions.
    The majority does not attempt to argue that the Briseno factors, standing
    alone, fall within the national consensus. Indeed, the opinion seems to suggest
    that states are empowered to ignore the national consensus. This national
    consensus tracks the “‘evolving standards of decency that mark the progress of
    a maturing society,’” which underlies Eighth Amendment jurisprudence. 
    Atkins, 536 U.S. at 312
    (quoting Trop v. Dulles, 
    356 U.S. 86
    , 101 (1958)). States may not
    52
    No. 08-70023
    ignore it in favor of their own restrictions that would allow for the execution of
    individuals that the national consensus has decided should not be executed. This
    is clear from the text of Atkins, which left to the states only “‘the task of
    developing appropriate ways to enforce the constitutional restriction upon [their]
    execution of sentences.’” 
    Atkins, 536 U.S. at 317
    (alteration in original)
    (emphasis added) (quoting 
    Ford, 477 U.S. at 416-17
    ). It does not give states the
    power to define what the constitutional restriction is; that had already been
    determined by the national consensus upon which the Atkins Court based its
    holding.
    In this case, the TCCA used the Briseno factors as a substitute for the
    clinical definition that Texas had previously pledged to follow and to which the
    national consensus generally conforms. It presents a “scientifically unsound and
    Atkins-violative assessment[] of adaptive functioning.” Blume, supra note 13, at
    706. Moreover, standing alone, the Briseno factors turn on its head the
    consensus’s approach to determining whether the petitioner has significant
    limitations in adaptive functioning. The AAMR and APA correctly assess
    adaptive functioning by analyzing the petitioner’s limitations. According to the
    AAMR, a person who is deficient in two out of the ten AAMR adaptive skill areas
    may be categorized as having significant limitations in adaptive functioning. The
    Briseno factors function in the opposite manner. According to the district court
    below, which the majority today affirms, the fact finder may find that a
    petitioner is not mentally retarded merely because he meets one of the seven
    Briseno factors. Moreover, several of the Briseno factors are markedly different
    from the clinical adaptive skill areas, and several are based on a person’s actions
    in a single moment instead of over a person’s lifetime. In other words, if the
    Briseno factors, standing alone, are allowed to replace an analysis that generally
    conforms to the clinical definitions, a single area or moment of strength can
    discount substantive evidence of significant limitations in numerous areas of
    53
    No. 08-70023
    adaptive functioning. See Blume, supra note 13, at 717-18. Furthermore, the
    TCCA, in developing the Briseno factors, did not conduct an assessment of the
    national consensus or draw from the clinical definitions of mental retardation
    around which the national consensus has coalesced. The factors are unmoored
    from the national consensus’s general understanding of what constitutes mental
    retardation. Used alone, these factors may determine that a subclass of persons
    protected by Atkins’s holding are, indeed, death eligible in Texas. The use of the
    Briseno factors in the present case therefore is clearly “contrary to . . . clearly
    established Federal law, as determined by the Supreme Court of the United
    States.” 28 U.S.C. § 2254(d)(1).
    VIII.
    Chester’s claim that he is mentally retarded must be adjudicated in a
    manner that is consistent with Atkins. The TCCA’s adjudication of Chester’s
    claim was contrary to the law that Atkins clearly established. See Williams v.
    
    Quarterman, 551 F.3d at 358
    (5th Cir. 2008) (“A state court decision is contrary
    to clearly established federal law if it ‘applies a rule that contradicts the
    governing law set forth in [Supreme Court] cases . . . .’” (first alteration in
    original) (quoting Williams v. 
    Taylor, 529 U.S. at 405
    )). Accordingly, I would
    vacate the judgment of the district court and remand this case to allow the
    district court to determine, not inconsistently with this opinion and pursuant to
    the federal law clearly established by the Supreme Court in Atkins, whether
    Chester is mentally retarded under a definition of mental retardation that
    “generally conform[s] to the clinical definitions” set forth in 
    Atkins, 536 U.S. at 317
    n.22, and thus “fall[s] within the range of mentally retarded offenders about
    whom there is a national consensus,” 
    id. at 317
    , and hence is protected from
    execution by the Eighth Amendment.
    54