The unanimous decision, which approved the Department of Corrections switch from a three-drug execution cocktail to one drug, cleared the way for Warren Lee Hill's execution, The Atlanta Journal-Constitution reported.
On July 23, the state Supreme Court halted Hill's execution -- just hours before it was scheduled to take place -- to give the court time to decide whether the Department of Corrections violated a state law that requires a public hearing before any change to the execution process may be made.
Hill was serving a life sentence for the murder of his girlfriend when he was found guilty of killing fellow inmate Joseph Handspike and sentenced to death in 1990.
Hill appealed the death sentence on grounds that he is mentally disabled, which would have made him ineligible for execution. However, the appeals court declined to overturn the death sentence because Hill failed to prove beyond a reasonable doubt he had a disability, the newspaper said.