(WASHINGTON) — More than 20 years ago, the Supreme Court outlawed the execution of intellectually disabled people convicted of capital crimes as “cruel and unusual” punishment forbidden by the Eighth Amendment.
In a major case from Alabama before the Supreme Court on Wednesday, the justices are asked to clarify who qualifies as “intellectually disabled” and what role intelligence quotient — also known as IQ — test scores play in making the determination.
Joseph Clifton Smith, an Alabama man who brought the case, confessed to a 1997 murder during a robbery, but challenged his death sentence on grounds he has had “substantially subaverage intellectual functioning” since a young age.
Smith has taken five separate IQ tests over nearly 40 years, scoring 75 in 1979, 74 in 1982, 72 in 1998, 78 in 2014 and 74 in 2017.
People below 70 are generally considered to have an intellectual disability, but major American medical groups urge a holistic assessment that also looks at social and practical skills.
The groups note that standardized test scores alone should not be conclusive. Smith’s score of 72, for example, could be 69 when factoring the 3-point margin of error.
“Intellectual disability diagnoses based solely on IQ test scores are faulty and invalid,” attorneys for the American Psychological Association and American Psychiatric Association told the court in a legal brief. “But IQ test scores remain relevant; IQ tests are a scientifically valid means to ascertain estimates of an individual’s intellectual ability. The key is to understand both the value of IQ tests and their limits.”
Smith, who allegedly suffered physical and verbal abuse as a child, consistently functioned two grade-levels below his placement in school, according to court documents. Smith’s school classified him as “Educable Mentally Retarded” in 7th grade before he eventually dropped out.
Two lower federal courts ruled that a holistic analysis of Smith’s IQ scores and other evidence, including his behavioral history and school records, proved he is intellectually disabled and should spend life behind bars rather than face execution.
Alabama wants the justices to toss out that assessment.
“Joseph Smith is not intellectually disabled, and the Eighth Amendment does not override the death sentence he earned for murdering Durk Van Dam,” the state argued in its brief to the court. “Whether and how to weigh multiple IQ scores is left to state discretion.”
The state says intellectual disability can only be proven by an IQ score of 70 or less by a preponderance of the evidence.
The Supreme Court’s decision in the case will determine whether Smith lives or dies.
More broadly, the ruling could determine how many other borderline intellectually disabled people on death row could be able to convert their death sentences into life behind bars.
By one estimate, as many as 20% of the 2,100 people on death row in the U.S. may have some degree of intellectual disability, according to the Death Penalty Information Center.
A ruling in the case — Hamm v. Smith — is expected by the end of June 2026.
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