One witness said they heard Butts ask Parks for a ride and other witnesses testified they saw Parks drive away from the store with Wilson and Butts inside the car.
Parks was soon found lying face down in a residential street. He had suffered a fatal shotgun blast to the back of his head.
It’s unclear who pulled the trigger, although Wilson initially told law enforcement officers that it was Butts who fired the fatal shot, according to court records.
The federal appeals court in Atlanta last August denied Wilson's attempt to reopen the case. On May 28, the U.S. Supreme Court declined to hear Wilson's appeal.
The first person put death by lethal injection in Georgia this year was Scotty Morrow. His execution was carried out at the Georgia Diagnostic and Classification Prison in Jackson on May 2.