The Georgia Board of Pardons and Paroles on Monday delayed a decision on the Troy Davis execution after hearing pleas from  the families of both the inmate and the victim.

The death row inmate, who had been scheduled to die Wednesday, maintains his innocence in the 1989 murder of off-duty Savannah Police Officer Mark MacPhail, and the case has attracted international attention. Thousands of people attended rallies in Atlanta to oppose his execution.

The decision to execute Davis was postponed for the fourth time in four years when the parole board announced Monday that it would not take an immediate decision on clemency.

Davis' lawyers made a three-hour presentation to the board Monday, after which attorney Stephen Marsh said, We believe we have established substantial doubt in this case, the Atlanta Journal Constitution reported

I will never have closure, Anneliese MacPhail, the slain cop's mother, told CNN. But I may have some peace when he is executed.

MacPhail, 27, was the security officer outside a Savannah bus station on Aug. 19, 1989, when he was gunned down. He left behind a wife and two young children.

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.

In 2008, the board had approved his execution, but three new members have joined since then.

Davis has always maintained his innocence; those opposing his execution include former President Jimmy Carter, Archbishop Desmond Tutu and Pope Benedict XVI.

Supporters note that 10 witnesses have signed affidavits recanting their statements, saying police coerced them into accusing Davis.

The Georgia Board of Pardons and Paroles received petitions with 663,000 names urging clemency on Thursday.

Davis’ lawyers are using social media to gather support.  

I think these people are just against the death penalty, Anneliese told CNN, adding that they have no idea what's going on. ... They don't know what happened. .. I'm not out after blood, I'm after justice. I want my son to rest in peace.

 Spencer Lawton, then Chatham County district attorney, in 2008 gave a statement in which he said that Davis was at a pool party in Savannah when he shot another man, Michael Cooper, in the face, CNN reported.

If I knew then what I know now, Brenda Davis, one of the jurors in the trial told CNN in a 2009 interview, Troy Davis would not be on death row. The verdict would be 'not guilty.'

A march in downtown Atlanta beginning at Ebenezer Baptist Church included Martin Luther King III, son of the late civil rights leader, Reuters reported.