The U.S. Supreme Court has refused to review the appeal of a Houston man on death row for the 1992 slaying of a 9-year-old boy.
The justices offered no comment Monday in rejecting the case of 58-year-old Perry Allen Austin.
Austin was serving a 30-year term for sexual assault on a child when he pleaded guilty in April 2002 to capital murder for injecting David Kazmouz with a pain killer and then slitting the boy's throat. His skeletal remains were found in Houston in 1993. Austin confessed in 2001.
Attorneys have argued in appeals he wasn't mentally competent to plead guilty. Prosecutors described Austin as a drug courier for a Houston street gang.
He volunteered for execution, then changed his mind a week before his scheduled punishment in 2003.