Troy Davis, the Georgia man who was executed late Wednesday, told his family and supporters before his death to keep fighting to clear his name.

Davis was executed at 11:08 p.m., four hours after he was scheduled to receive the lethal injection, New York Times reported.

May God have mercy on your souls,” were Davis's last words to prison officers before execution, The Sydney Morning Herald reported.

Before the execution Davis had spent few hours with his family. He told his family and friends to continue with the protest to clear his name and to prove him innocent. Davis also told the son and the brother of the dead officer, Mark MacPhail, that he was innocent and not responsible for his death.

The execution was delayed by four hours from the scheduled time because Davis’ lawyer asked for a polygraph test and Georgia prison officials were waiting for the court’s decision late into the evening for the test.

Davis’ family members and his supporters gathered near the entrance of the prison in Jackson during the time of the execution.

We're calling on everyone to stay calm, Benjamin T. Jealous, president of the NAACP, told The New York Times.

Davis’ lawyers and supporters appealed to various state and federal courts to stop the execution but were rebuffed, and Davis' last option seemed lost when the Georgia Board of Pardons and Parole rejected his request to take a polygraph test and the Georgia Supreme Court refused to stay the execution or to commute his death sentence to life in prison without parole.

Thousands of people gathered outside the prison to stop the execution but there were some counter-protestors, including the family of MacPhail.

MacPhail’s family told reporters that they believed Davis was guilty and should be executed.

Davis was 19 years old when he was arrested for the murder. Eyewitnesses' statements, two years later, influenced a jury to sentence him to death.

MacPhail, 27, was working as a security officer outside a Savannah bus station on Aug. 19, 1989, when he interfered in an argument between several men and was shot in the heart and face.

Justice was finally served for my father, said Mark MacPhail Jr., who was an infant when his father was gunned down. The truth was finally heard.

David is the fourth prisoner to be executed this year in Georgia.