The U.S. Supreme Court has declined to hear an appeal from an Oklahoma man who was sentenced to death for the 1992 murder of a convenience store owner during a robbery.
The Oklahoman reports that Emmanuel Littlejohn had asked the court to consider if his sentence was unconstitutional because jurors didn't hear of how brain damage could've explained his actions. Littlejohn has admitted to taking part in the robbery, but denies firing the shot that killed 31-year-old Kenneth Meers.
Assistant Attorney General Jennifer Crabb says Littlejohn's attention deficit disorder, impulse control disorder and personality traits don't account for his criminal behavior.
Littlejohn has now exhausted his appeals and is eligible for execution.
No execution dates in Oklahoma have been set as the state works on a new execution protocol using nitrogen gas.