Sept. 20, 2011 -- Troy Davis has run out of appeals.

Davis was denied clemency this morning by the Georgia Board of Pardons and Paroles, the only authority in the state that can commute a death sentence, and is set to be executed Wednesday night at the state prison in Jackson.

"The board has considered the totality of the information presented in this case, and thoroughly deliberated on it," said board spokesman Steve Hayes in a terse statement. "After which the decision was to deny clemency."

Davis was convicted in 1989 for the shooting death of off-duty officer Mark Allen McPhail. McPhail was working as a night security guard in Savannah when he ran to help a homeless man who was the victim of an assault. In the chaos that followed, McPhail was shot three times.

Police never found the murder weapon, and seven of the nine witnesses who said Davis was the shooter have since changed their story.

In 2007, one of those seven witnesses told ABC News that she initially pointed the finger at Davis because of police coercion, and that she believed the real killer was one of the other witnesses. She said she feared he would come after her if she told the truth. She did not want to be identified at the time.

Another woman told the parole board Monday that she too believed the real killer went free. Quiana Glover said that she overheard Slyvester "Redd" Coles say that he was actually the shooter. Coles had been drinking heavily, she said. They were both at a party.

Coles, it turns out, was the first to implicate Davis, and at trial he testified that he left the scene before the shots were fired.

The officer's family said after the decision was announced that they simply want justice.

"This is what we've been fighting for, for twenty years," said Anneliese McPhail, the officer's mother. "We're ready to close this book and start our lives."

She points out that this is Davis's fourth execution date, in a case that at one point went before the US Supreme Court. McPhail's family has never had any doubt that Troy Davis was the shooter. They believe he was properly convicted.

There are still a good many people who believe the state of Georgia is about to execute an innocent man.

Georgia Representative John Lewis said that this is a "sad day for Georgia." "We have confirmed that the administration of law is more important than the search for justice."

The NAACP, Amnesty International, and other groups have all decried the parole board's decision, all suggesting that life in prison would have been a more just decision.

At time of McPhail's murder in 1989, the shooting divided Savannah along racial and socio-economic lines. The police were under tremendous pressure to solve the case, and put the killer away.

Davis is scheduled to die at 7 p.m. Wednesday night. This is the fourth time the state has scheduled the death penalty for Davis since he was found guilty.