Georgia inmate Troy Davis's last-ditch request for a lie detector test to try to prove his innocence ahead of tonight's planned execution has been denied by Georgia Department of Corrections. Defence lawyer Stephen Marsh said he had hoped the polygraph would convince the state pardons board to reconsider a decision against clemency, which was rejected yesterday. Davis, 42, is scheduled to die at 7pm tonight. It is the fourth time in four years that Davis' execution has been scheduled by Georgia officials.