Daryl Atkins was convicted in 1998 of abducting, robbing and killing a young Air Force mechanic. During his trial’s sentencing phase the defense asserted, based on a score of 59 on an IQ test, that Atkins was mildly mentally retarded and for that reason should not receive the death penalty. But Atkins was sentenced to death by lethal injection. His sentence was reversed and his case was remanded was after the Supreme Court ultimately ruled that executions of mentally disabled criminals were cruel and unusual punishments prohibited by the Eighth Amendment. “The large number of states prohibiting the execution of mentally retarded persons,” wrote Stevens, showed that “our society views mentally retarded offenders as categorically less culpable than the average criminal.”

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