ATLANTA (AP) — Georgia’s top court has refused to halt the execution of inmate Troy Davis, leaving him nearly out of options with less than two hours until he’s scheduled to die for the killing of a policeman.

Davis and his supporters have maintained his innocence. Prosecutors have stood by the case.

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The Georgia Supreme Court on Wednesday rejected the last-ditch appeal by Davis’ lawyers. Earlier, a Butts County Superior Court judge also declined to stop the execution. Davis was convicted in the 1989 slaying of off-duty Savannah police officer Mark MacPhail.

His attorneys had filed an appeal challenging ballistics evidence linking Davis to the crime, and eyewitness testimony identifying Davis as the shooter. The case could still end up before the U.S. Supreme Court.

Copyright 2011 The Associated Press.