Supreme Court grapples with allowing death row inmate’s second bid to avoid execution

The Supreme Court heard arguments over whether Dexter Johnson may make a second legal challenge to his death sentence, based on a change in how intellectual disability is assessed. The case tests the limits of a federal rule that generally allows death row prisoners only one round of post-conviction appeals, and could affect how later changes in clinical standards are considered.

Johnson relies on the 2002 Supreme Court ruling in *Atkins v. Virginia*, which bars execution of people with intellectual disabilities. Although his first appeal took place after that ruling, he argues that a later revision to the American Psychiatric Association’s diagnostic manual now places his IQ within the intellectual disability category. He says this change allows him to use an exception for claims based on a new constitutional rule.