Intellectual Disability and the Death Penalty Eleven years ago, the Supreme Court banned the execution of intellectually disabled people in Atkins v. Virginia. Ever since, some states have worked to circumvent that ruling by defining intellectual disability using unscientific standards or by making it nearly impossible to prove. On Monday, the justices indicated that they may at last be ready to clarify the Atkins decision by agreeing to consider whether a Florida law defines intellectual disability too narrowly. Freddie Lee Hall was sentenced to death for the 1978 murder of a 21-year-old pregnant woman, Karol Hurst. The Florida trial court found that Mr. Hall had been "mentally retarded his entire life," but capital punishment was not then prohibited in such cases. Mr. Hall appealed his death sentence following the 2002 Atkins ruling, which held that people with intellectual disabilities are less culpable because of their "reduced capacity" for understanding, reasoning and impulse control. But the Florida Supreme Court ruled against him because he scored between 71 and 80 on recent I.Q. tests, and state law requires a score of 70 or lower for a finding of intellectual disability. Such a "bright line" I.Q. cutoff has been roundly rejected by mental-health experts, who say that the diagnosis of intellectual disability is complex and I.Q. tests are approximate measures but do not provide a complete picture. There is no magic score above which intellectual disability doesn't exist. Florida is far from alone in its efforts to undermine the court's ruling. In Texas, the state's highest criminal court decides whether a defendant is disabled enough to be executed by using unscientific standards based on outdated stereotypes. And in Georgia, defendants must prove intellectual disability beyond a reasonable doubt - an arguably unconstitutional standard no other state uses. In a promising development, the Georgia Legislature agreed last week to reconsider that standard. Rich Golick, a Republican state representative, said, "When you're an outlier, you really ought not to stick your head in the sand." The Supreme Court is right to revisit its 2002 ruling, which gave states too much leeway to define intellectual disability. It should take this opportunity to reaffirm the central principle of Atkins and require states to adhere to medical consensus in defining intellectual disability.