Policy Issues

Intellectual Disability

It is unconstitutional to impose the death penalty upon individuals with intellectual disability. But poor legal representation and onerous evidentiary requirements still result in death sentences and executions of intellectually disabled defendants.

DPIC Podcast: Discussions With DPIC

DPIC Podcast: Discussions With DPIC

Intellectual Disability and the Death Penalty, With Law Professor John Blume


While stopping short of abolishing the death penalty, the U.S. Supreme Court has taken measures to limit its applicability so that it is used primarily in cases where the defendant had the most culpability. People with intellectual disability are not in that group. Occasionally, states, too, determined that the death penalty could be too harsh as applied to some defendants, and many passed laws exempting people with limited intellectual ability from the death penalty.

The mental health community has provided clear criteria for a finding of intellectual disability: significant limitation in intellectual ability and adaptive behavior, manifesting itself prior to the age of 18.

Although the question of a national ban on the use of capital punishment for those with intellectual disability was rejected by the Supreme Court in 1989 because so few states had taken action on their own, the issue re-emerged in 2002 with a new consensus. Thirty states had either ended the use of the death penalty entirely, or at least for those with intellectual disabilities. In Atkins v. Virginia, the Court held that the nation’s standards of decency had evolved to the point where no such executions should occur. It also concluded that there was little if any deterrent or retributive effect from executing such defendants.

At Issue

The Atkins case was a seminal moment in the history of the death penalty, not only because it spared the lives of a vulnerable class of defendants, but it also provided a blueprint for achieving other limitations on the practice, or even for eliminating it altogether. Even after the Court’s decision in 2002, some states continued to use arcane practices in the determination of intellectual disability, so further supervision has been required.

What DPIC Offers

DPIC traces the history of this important ruling, noting the legislative efforts in various states and the pivotal cases that brought this issue to the fore. It provides access to some of the research regarding how many defendants with intellectual disability have been removed from death row and how states apply this ruling at differing times during the process leading up to sentencing.

News & Developments


May 25, 2022

Legal Analysts Blast Supreme Court Ruling Denying Prisoners Who Were Incompetently Represented in State Courts Access to Federal Courts to Prove Innocence, Constitutional Violations

In an opin­ion legal experts have blast­ed as night­mar­ish” and an abom­i­na­tion,” the U.S. Supreme Court has ruled in two Arizona death penal­ty cas­es that 1990s amend­ments to the fed­er­al habeas cor­pus law per­mit state pris­on­ers who were pro­vid­ed ine…