The Georgia Board of Pardons and Paroles has denied clemency for a man convicted of killing a woman he met in a nightclub.

Marcus Ray Johnson is scheduled to die at 7 p.m. Thursday at the state prison in Jackson. The 50-year-old was convicted in the March 1994 rape and murder of Angela Sizemore in Albany.

The parole board is the only entity authorized to commute a death sentence. The board held a hearing for Johnson on Wednesday and voted against granting clemency.

Earlier Wednesday, a judge rejected a constitutional challenge to Johnson's sentence and conviction and declined to stop his execution. His lawyers have appealed to the state Supreme Court.

Johnson's attorneys argue he shouldn't be executed because doubts remain about his guilt. Prosecutors say there is no doubt.