Jimmy Carter: Troy Davis execution shows death penalty "unjust and outdated," says ex Pres.

Troy Davis and Anti-death penalty supporters
Troy Davis supporters in Jackson, Ga. comfort each other after hearing that the U.S. Supreme Court rejected the last minute plea of the death row inmate, inset, Wednesday, Sept. 21, 2011. AP Photo

(CBS/AP) ATLANTA -  Former President Jimmy Carter says the execution of death row inmate Troy Davis shows that the U.S. death penalty system is "unjust and outdated."

The Georgia Democrat said Thursday in a statement to The Associated Press that he hopes "this tragedy will spur us as a nation toward the total rejection of capital punishment."

Davis was executed late Wednesday night for the 1989 murder of off-duty Savannah police officer Mark MacPhail. His supporters say he was the victim of mistaken identity, while prosecutors and MacPhail's family said justice was finally served after four years of delays.

Brian Kammer, one of Davis' lawyers, said the state may have executed an innocent man. "I think Georgia has shamed itself in a very profound way by failing to err on the side of life when there is meaningful, significant doubt," he told the Atlanta Journal-Constitution.

Outside the prison, a crowd of more than 500 demonstrators cried, hugged, prayed and held candles. They represented hundreds of thousands of supports worldwide who took up the anti-death penalty cause as Davis' final days ticked away.

Former FBI Director William Session also spoke with AJC saying, "When it comes to the sentence of death, there should be no room for doubt."

Davis maintained his innocence till his death saying moments before he was executed, "All I can ask...is that you look deeper into this case so that you can finally see the truth. I ask my family and friends to continue to fight this fight."

No gun was ever found, but prosecutors say shell casings were linked to an earlier shooting for which Davis was convicted.

Witnesses placed Davis at the crime scene and identified him as the shooter, but several of them have recanted their accounts and some jurors have said they've changed their minds about his guilt.

Others have claimed a man who was with Davis that night has told people he actually shot the officer.

"If one of our fellow citizens can be executed with so much doubt surrounding his guilt, then the death penalty system in our country is unjust and outdated," former Pres. Carter said.

Complete Coverage of Troy Davis on Crimesider