In Atkins v. Virginia, 535 U.S. 304 (2002), the Supreme Court held that the Fourteenth and Eighth Amendments to the U.S. Constitution forbid the execution of individuals with intellectual disabilities. After that decision, Freddie Lee Hall asked a Florida state court in a post-conviction proceeding to vacate his death sentence based on evidence that he had an IQ of 71. Hall v. Florida, 134 S.Ct.1986, 1988 (2014). The state court denied his petition, holding that the relevant Florida statute required a petitioner to show that he had an IQ of 70 or below before being allowed to present mitigating intellectual disability evidence. The Florida Supreme Court affirmed, upholding the constitutionality of the Florida statute. Hall v. State, 109 So. 3d. 704 (2013).

The Florida statute at issue defined "significantly subaverage general intellectual functioning" as "performance that is two or more standard deviations from the mean score on a standardized intelligence test"--i.e. 70 or below. Florida treated 70 as a mandatory cutoff, meaning that if a petitioner tested above that number "sentencing courts [could not] consider even substantial and weighty evidence of intellectual disability as measured and made manifest by the defendant's failure or inability to adapt to his social and cultural environment, including medical histories, behavioral records, school tests and reports, and testimony regarding past behavior and family circumstances." Hall v. State, 134 S.Ct. 1986, 1994 (2014).

Richard J. Bonnie, The Constitutional Importance of Conforming to Accepted Professional Practice in Adjudicating Claims of Intellectual Disability in Capital Cases: A Comment on Hall v. Florida, 134 S. Ct. 1986 , Developments in Mental Health Law, 9–14 (2015).