Atkins, Moore, and intellectual disability under Texas art. 46.05

The Eighth Amendment baseline from Atkins

The Supreme Court held in 2002 that the Eighth Amendment categorically prohibits the execution of persons with intellectual disability (then called mental retardation). The Court did not specify a fixed clinical test; it left the definition and procedural mechanism to the states. That delegation produced two decades of variation, including Texas's now-rejected Briseno framework, which used non-clinical lay factors derived from Of Mice and Men rather than current standards.

How Moore v. Texas reshaped the inquiry

In Moore v. Texas (2017) and Moore II (2019), the Supreme Court rejected the Court of Criminal Appeals' continued use of Briseno. The Court held that the determination must be informed by the medical community's diagnostic framework — in practice, the DSM-5 (or its successor, the DSM-5-TR) and the AAIDD manuals. The Court emphasized that lay stereotypes about how people with intellectual disability behave cannot replace clinical criteria.

After Moore, the CCA and Texas trial courts have consistently applied the three-prong clinical standard: (1) significantly subaverage general intellectual functioning, (2) significant deficits in adaptive functioning, and (3) onset during the developmental period. Each prong is anchored in clinical, not lay, evidence.

What Art. 46.05 actually does

Art. 46.05 establishes the procedural mechanism by which a person under a sentence of death (or whose case is otherwise before the trial court on competency for execution) raises intellectual disability or incompetency for execution. The statute provides for a written motion, court-appointed experts, a hearing, and a record reviewable by the Court of Criminal Appeals.

The three-prong clinical standard

Significantly subaverage intellectual functioning

Generally, a full-scale IQ approximately two standard deviations below the mean, with consideration of the standard error of measurement. The Supreme Court in Hall v. Florida rejected a rigid IQ-70 cutoff. Hall v. Florida.

Significant deficits in adaptive functioning

Conceptual, social, and practical adaptive domains, assessed via standardized instruments (Vineland, ABAS-3) plus collateral interviews with family, teachers, employers, and corrections personnel.

Onset during the developmental period

Before age 18 (or before age 22 under more recent AAIDD guidance). The record draws on school records, IEPs, juvenile records, and developmental milestones.

Procedural posture: when Art. 46.05 is the right vehicle

Art. 46.05 governs post-judgment intellectual-disability and competency-for-execution claims. Intellectual-disability claims raised at the original trial — whether to preclude the death penalty at the punishment phase or to support a not-guilty verdict on a separate ground — are litigated under different procedural pathways (jury instructions on the punishment-phase issue, expert testimony in case-in-chief, etc.).

For collateral and post-conviction work, intellectual-disability claims also appear in Art. 11.071 (death-penalty writ) applications and in federal habeas under 28 U.S.C. § 2254. Counsel should map the procedural vehicle to the relief sought before drafting the motion.

Evidence Texas courts now accept

Post-Moore, the evidentiary toolkit is more clinical and less anecdotal. Successful defense presentations typically include:

• Full IQ batteries with raw protocols, conducted by clinicians qualified to administer them.
• Adaptive-functioning instruments scored by qualified examiners.
• Records from the developmental period: school transcripts, IEPs, special-education evaluations, juvenile records, medical records.
• Collateral interviews with developmental witnesses — teachers, family members, employers — capturing concrete examples of functioning rather than generalized impressions.
• Expert testimony grounded in the current edition of the DSM and the AAIDD manual.

Practical implications for capital defense and post-conviction practice

For practitioners in the Texas Northern and Eastern federal districts and across the four-county DFW core, the Atkins/Moore framework is now well-settled in substance even though application varies case by case. Two trends matter:

1. Trial-court findings under Art. 46.05 receive deferential review on appeal. Counsel must build a complete clinical record at the trial-court hearing — appellate avenues for new evidence are narrow.
2. The relationship between intellectual disability and other diagnoses (autism spectrum, traumatic brain injury, comorbid learning disability) requires careful clinical sequencing. The defense expert should disentangle overlapping diagnoses with the same level of rigor a treating clinician would apply.

How the Texas Court of Criminal Appeals interpreted Moore II

After Moore I, the CCA initially attempted to retain some of the Briseno-era reasoning. The Supreme Court in Moore II rejected that approach explicitly and remanded with instructions to apply the clinical standard. The CCA has since aligned with the clinical framework, citing the DSM and AAIDD criteria as the operative measure.

The post-Moore CCA opinions emphasize:

• The medical community's current diagnostic standards control the inquiry.
• Lay stereotypes are inadmissible as substitutes for clinical evidence.
• Adaptive deficits must be measured by the clinical instruments, not by anecdotal showings of "what the defendant can do."
• Strengths and weaknesses must be weighed together, but strengths do not categorically exclude an intellectual-disability finding.

The CCA has also clarified that the trial court's findings are reviewable for sufficiency of the clinical basis, not for general persuasiveness. Decisions resting on Briseno-style reasoning continue to be reversed on appeal even after the initial Moore remand.

Building the clinical record at the trial court

A complete Art. 46.05 record at the trial court includes:

1. IQ batteries. The full WAIS-IV (now WAIS-V) protocol, scored by a qualified examiner, with attention to standard error of measurement and any practice-effect adjustments.
2. Adaptive-functioning instruments. Vineland-3 or ABAS-3, administered by a qualified examiner with collateral interviews. The clinician must score and interpret consistent with DSM and AAIDD guidance.
3. Developmental records. School transcripts, IEPs, special-education evaluations, medical records from childhood, juvenile-court records.
4. Collateral witnesses. Teachers, family members, employers, and others with developmental-period knowledge.
5. Expert reports. A written report by the testifying expert summarizing the diagnostic process and conclusions.

Trial counsel who builds the record in this way preserves the case for both the trial-court finding and any appellate review.

The federal-habeas pathway after exhaustion

If the Texas trial court denies Art. 46.05 relief and the CCA affirms, the petitioner can pursue federal habeas relief under 28 U.S.C. § 2254. Federal habeas in death-penalty cases is governed by:

• The Anti-Terrorism and Effective Death Penalty Act of 1996 (AEDPA), 28 U.S.C. § 2254(d).
• The exhaustion requirement (claims must have been fairly presented to the highest state court).
• The statute of limitations (one year under § 2244(d)).
• The deferential standard of review for state-court adjudications on the merits.

For an Atkins/Moore claim that has been adjudicated on the merits in state court, federal habeas relief is available only if the state-court decision was contrary to or an unreasonable application of clearly established Supreme Court precedent. Moore I and Moore II remain the clearly-established law. State-court decisions that revive the rejected Briseno framework, or that decline to engage with current clinical standards, present federal habeas grounds.

Counsel should preserve every claim at every state-court stage and document the federal-question presentation. AEDPA's exhaustion and procedural-default rules are unforgiving.

Engaging counsel and next steps

Atkins, Moore, and Art. 46.05 work is among the most technically demanding criminal-defense practice in Texas. The clinical record is the case. Defense counsel who treats the clinical work as ancillary loses; counsel who centers the clinical record builds appellate strength regardless of trial-court outcome.

The DFW criminal-defense landscape has evolved substantially in the post-pandemic period. Caseloads have shifted, prosecutor staffing has changed, and several core statutes have been amended by the 88th and 89th Legislatures. Counsel should periodically refresh the working knowledge base — bar CLE materials, the Texas District & County Attorneys Association publications, and the Court of Criminal Appeals' recent opinions are reliable starting points.

For families facing a capital case with intellectual-disability indicators, the work begins long before trial. Documentary evidence of developmental-period functioning — school records, juvenile-court files, family interviews, medical records — should be assembled and preserved early.

For potential clients in Collin, Dallas, Denton, Tarrant, Rockwall, Kaufman, Ellis, Johnson, and Hunt counties, consultations at L and L Law Group are free and confidential. The earlier counsel is engaged, the more strategic options remain open. Many of the procedural levers discussed in this article narrow or close as the case progresses; an attorney engaged at the magistrate stage has tools that an attorney engaged at sentencing does not.

Closing observations on the post-Moore framework

The clinical-standard framework after Moore II has stabilized. The CCA applies the three-prong test consistently in opinions of the past several years. Federal habeas review under AEDPA gives weight to state-court findings on the clinical questions.

Counsel should not treat clinical determinations as the only avenue. Even within a clinical framework, the specific instrument selection, the choice of collateral witnesses, the developmental-period evidence, and the expert's qualifications all matter. Two cases with similar IQ scores can produce different outcomes based on the quality of the adaptive-functioning evidence.

For appellate practice, preservation at the trial-court level is essential. AEDPA's deferential standard means that a state-court adjudication, even if questionable, is hard to overturn federally. Build the record at trial; the appellate posture follows from the record.

References

1. Atkins v. Virginia, 536 U.S. 304 (2002), law.cornell.edu/supremecourt/text/536/304.
2. Moore v. Texas, 581 U.S. 1 (2017), law.cornell.edu/supremecourt/text/15-797.
3. Hall v. Florida, 572 U.S. 701 (2014), law.cornell.edu/supremecourt/text/12-10882.
4. Texas Code of Criminal Procedure art. 46.05, statutes.capitol.texas.gov/Docs/CR/htm/CR.46.05.htm.
5. Texas Code of Criminal Procedure art. 11.071 (death-penalty post-conviction), statutes.capitol.texas.gov/Docs/CR/htm/CR.11.071.htm.