The Uneven Legacy of Atkins: How States Vary in Interpreting Intellectual Disability in Death Penalty Cases
The Supreme Court’s decision in Atkins v. Virginia (2002) was meant to set a national precedent: individuals with intellectual disability (ID) cannot be executed. But over two decades later, this constitutional protection looks wildly different from state to state—and the result is a deeply fragmented, and at times unjust, system.
A Patchwork of Justice
Despite the clear constitutional ruling, Atkins left it up to individual states to define what intellectual disability means, how it should be assessed, and who carries the burden of proof. This open-ended approach has led to striking inconsistencies in how cases are handled across jurisdictions.
For example:
IQ thresholds differ: Some states rigidly enforce a cutoff score of 70, while others consider measurement error or allow for a range of scores.
Burden of proof varies: In some jurisdictions, the defense must prove the presence of ID; in others, the state must prove its absence—often at drastically different standards of evidence.
Timing of hearings fluctuates: Some states require a pretrial Atkins hearing, while others leave the decision to a sentencing-phase jury.
These inconsistencies can mean that two defendants with nearly identical cognitive profiles may face entirely different fates depending solely on where they were prosecuted.
Uneven Playing Fields for Forensic Psychologists
Forensic psychologists navigating this landscape must contend with varying definitions, statutes, and legal expectations. There is no federally mandated standard for how to conduct an Atkins evaluation, which leads to discrepancies in:
What tests are accepted
How adaptive behavior is measured
What training or credentials evaluators must have
This not only complicates the expert’s role—it raises questions about the fairness and scientific rigor of the process itself.
When Legal Definitions Outpace Clinical Science
Perhaps the most troubling reality is that some state statutes are out of sync with clinical consensus. For example, an evaluator may apply DSM-5 or AAIDD criteria, only to have that interpretation rejected by a court favoring outdated definitions or oversimplified thresholds.
The result? Individuals with bona fide intellectual disabilities may be ruled eligible for execution—not because of faulty evaluations, but because the law itself is misaligned with science.
The Stakes Couldn't Be Higher
In no other area of psychological assessment do we see this level of variability with such life-altering consequences. While Atkins was a landmark step forward, the lack of standardization continues to undermine its spirit.
As forensic psychologists, we must not only stay informed about these jurisdictional nuances—we must actively advocate for clearer, fairer, and more scientifically grounded procedures. The life of a defendant should never hinge on geographic happenstance.
