By Lisa Soronen

Every term, without fail, the U.S. Supreme Court issues at least one opinion that will require some state legislatures to rewrite statutes.

This term the Supreme Court has put nine states on notice that their death penalty statutes defining intellectual disability cannot have a rigid cut at a 70 or less IQ score. The Supreme Court’s decision also includes an explicit nod to similar choices by state legislatures.  

In Hall v. Florida, the Supreme Court held 5-4 that if a capital defendant’s IQ falls within the standard error measurement (SEM) for intellectually disabled, the defendant must be allowed to present additional evidence of intellectual disability. Hall may require up to nine states to rewrite death penalty statutes with strict IQ cutoff scores of 70.

In 2002 in Atkins v. Virginia, the Supreme Court held the Eighth Amendment forbade the execution of persons with intellectual disabilities. Florida’s death penalty statute defines intellectual disability as requiring “an IQ test score of 70 or less.” Capital defendant Freddie Lee Hall’s lowest IQ score was 71.

The Supreme Court agreed with Hall that Florida’s rigid 70 or less IQ rule was unconstitutional. While the court noted that the medical community agrees that an IQ of 70 or less indicates intellectual disability, “Florida's rule disregards established medical practice in two interrelated ways.It takes an IQ score as final and conclusive evidence of a defendant's intellectual capacity, when experts in the field would consider other evidence. It also relies on a purportedly scientific measurement of the defendant's abilities, his IQ score, while refusing to recognize that the score is, on its own terms, imprecise.” 

Instead of using a rigid 70 or less IQ cutoff, states should take into account SEM, which is generally plus or minus 5 points. So if a capital defendant’s IQ is 75 or less he or she may present additional evidence of intellectual disability.

Another factor in the court’s reasoning in this case was that every state legislature except Virginia, which has defined intellectual disability since Atkins, has taken a position contrary to Florida’s. 

Two other states—Kentucky and Virginia—have strict IQ cutoffs like Florida's and six other states—Alabama, Arizona, Delaware, Kansas, North Carolina, and Washington—may have bright-line cutoffs, depending on how courts interpret the statutes. These nine states should reconsider their statutes defining intellectual disability for death penalty purposes in light of Hall.  

Lisa Soronen is executive director of the State and Local Legal Center. She writes frequently on U.S. Supreme Court cases for the NCSL Blog.

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