Biases & Vulnerabilities

Intellectual Disability

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

144

The number of individuals who have had their death sentences vacated due to intellectual disabilities since 2002.

120/144

83% of those whose sentences were vacated were people of color.

Overview

The question of a national ban on the use of capital punishment for those with intellectual disability was initially rejected by the United States Supreme Court in 1989, in part because at that time only a few states had adopted legislation that protected this vulnerable group of people from the death penalty. The Court found insufficient evidence that society disapproved of the practice. But just 13 years later, there was a new consensus. Thirty states had either ended the use of the death penalty entirely, or had specifically exempted people with intellectual disabilities. In Atkins v. Virginia (2002), the Court held that was evidence that society no longer supported the execution of people with intellectual disability. The Court also noted the special vulnerabilities of people in this group, including the risk that they would falsely confess, and concluded that the traditional justification of deterrence for this group was not applicable.

At Issue

The Atkins case was a seminal moment in the history of the death penalty, not only because it had the potential to spare the lives of many vulnerable defendants, but also because the Court’s rationale provided a blueprint for achieving other limitations on its use. But the Court left the critical decision of determining who had intellectual disability to each state — leading to a patchwork of inconsistent laws and practices that left some people without the protection they deserved.

What DPIC Offers

DPIC traces the history of this important ruling, noting the legislative efforts in various states and pivotal cases. It provides access to research regarding how many defendants have been found to have intellectual disability and removed from death row, and how states have complied with this ruling.

News & Developments


News

Jun 01, 2026

Supreme Court Roundup: Decisions Allow Jury Discrimination Claim to Proceed and Keep Protections for Intellectually Disabled in Place

In recent weeks, the U.S. Supreme Court issued decisions regarding two key types of claims that often appear in capital cases: prosecutorial misconduct and intellectual disability. A bipartisan group of conservative and liberal justices carried each decision. The Court ruled in favor of Mississippi prisoner Terry Pitchford, allowing his jury discrimination claim to proceed, as well as Florida prisoner Gary Whitton, based on a lower court error in weighing his claim that prosecutors presented…

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News

May 12, 2026

A Man With Intellectual Disability Was the 600th Person Executed in Texas

On May 14, 2026, Edward Busby became the 600th person executed in Texas in the last 50 years. A three-judge panel of the United States Court of Appeals for the Fifth Circuit had temporarily stayed his execution, but the U.S. Supreme Court lifted the stay, allowing the execution to proceed. Mr. Busby is a person whom all experts agree has intellectual disability, and he should therefore have been legally ineligible for execution. Mr. Busby’s case is illustrative of several patterns that show…

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News

Apr 21, 2026

What to Know: Intellectual Disability & the Death Penalty

DPI’s “What to Know” series examines capital punishment from multiple angles, one topic at a time. Each installment provides essential facts and data on specific aspects of the death penalty. Why it Matters: In 2002, the United States Supreme Court held that executing individuals with intellectual disability is unconstitutional. (Atkins v. Virgina). Before that decision, dozens of people with intellectual disabilities were legally executed. In Atkins, the Supreme Court explained that people…

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News

Apr 20, 2026

Texas Death Sentence Vacated for Mentally Ill and Intellectually Disabled Man After Half-Century on Death Row — And Nearly 40 Years Without a Lawyer

By the time 21-year-old Clarence Curtis Jordan shot a man during a grocery store burglary in 1977, he had been struggling for most of his life with hallucinations and intellectual deficits. His IQ score placed him in the bottom 0.5% of the population. He identified the president as “John Hill” and said he often saw “old, weird, burnt-up looking people” watching him. The Texas Court of Criminal Appeals (TCCA) found him incompetent to be executed in 1988. But Mr. Jordan then fell through the…

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News

Jan 07, 2026

New Report Examines Florida’s Unprecedented Execution Pace and Trends in 2025

The United States carried out 47 executions in 2025, and Florida carried out 19 — the highest number in state history and more than double its previous modern record, according to a year-end report from Floridians for Alternatives to the Death Penalty (FADP). Executions in Florida — which averaged one execution every 16 days from February 2025 through December 2025 — accounted for 40% of the 47 executions nationwide, making Florida a clear outlier in the use of the death penalty in the United States.

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