BATON ROUGE, La. (AP) — A legal team has petitioned the U.S. Supreme Court to hear its claim that Louisiana prosecutors withheld evidence for a murder trial that ended in a guilty verdict against an intellectually disabled teenager accused of killing a pizza deliveryman.

Corey Williams was 16 years old when police arrested him in the shooting death of Jarvis Griffin two decades ago in Caddo Parish, where prosecutors have been widely criticized for their aggressive approach to seeking the death penalty.

Earlier this week, a group of 44 former prosecutors and Justice Department officials -...