Despite high-profile protests and a last-minute appeal to the U.S. Supreme Court, convicted murderer Troy Davis was put to death in Georgia late Wednesday night by lethal injection.

Davis, 42, was scheduled to be executed by lethal injection at 7 p.m. EDT, for the 1989 shooting death of an off-duty Savannah police officer during a wild brawl in a Burger King parking lot. His lawyers and supporters fought feverishly to delay the execution -- based on doubts about the evidence used to convict him of murder -- but the U.S. Supreme Court rejected a last-minute appeal for a stay.

Pleading his innocence until the end, Davis, as he lay strapped to the execution gurney, looked at the slain officer's family and said he was sorry for your loss, but I did not personally kill your son, father and brother. I am innocent, witnesses reported him saying.

The incident that night was not my fault, I did not have a gun, Davis said, addressing everyone gathered. He also told his friends to continue to fight and look deeper into this case so you can really can finally see the truth.

Davis saved his final words for the prison staff: For those about to take my life, may God have mercy on your souls. May God bless your souls.

He was declared dead at 11:08 p.m. EDT, 15 minutes after the lethal injection process began.

Davis spent his last few hours with his family. Police in riot gear stood by while his supporters gathered outside the prison entrance. He didn't choose a last meal. 

On Tuesday, the Georgia Pardons Board had refused to commute Davis' sentence to life in prison without parole and denied his lawyers' request that he be allowed to take a polygraph test. Despite public outcry and pressure from prominent individuals and organizations, the board refused to revisit its decision on Wednesday. The Georgia Supreme Court also refused to intervene.

The Case: A 1989 Murder

Davis was convicted in 1991 of killing Mark MacPhail, a Savannah, Ga., police officer, in 1989. He insisted he was innocent, and his lawyers fought to get him a new trial, arguing that the evidence and testimonies used to convict him were flawed.

MacPhail was working as a security guard in 1989 and was shot while trying to help a homeless man whom Davis was beating in a Burger King parking lot, prosecutors said. No gun was found; Davis was found guilty on the basis of shell casings from an earlier shooting he had been convicted of, and testimony from several eyewitnesses.

Of the nine witnesses who testified against Davis in his original trial, seven have recanted their testimonies, saying the police had pressured them to implicate Davis; some went on to implicate another man, Sylvester Coles.

Such incredibly flawed eyewitness testimony should never be the basis for an execution, Stephen Marsh, one of Davis' lawyers, told The Atlanta Journal-Constitution. To execute someone under these circumstances would be unconscionable.

But state and federal courts ruled that the defense had not provided a substantive claim of innocence.

The slain officer's family said they have no doubts about Davis' guilt, however.

I'm not joyous, the victim's mother, Anneliese MacPhail, said. I'm feeling a little bit relieved. It has been a long, long battle. I'd like to close the book.