For Troy Davis, 41, the crime is allegedly murdering a policeman and the punishment is death. He is scheduled to get the lethal injection on Wednesday, but as his execution date nears, hundreds of protest rallies are being held worldwide in order to stop the judicial killing.

About 300 protest rallies were held worldwide on Friday ahead of a parole board hearing for the death row inmate. Davis' execution is planned for Sept. 21, more than two decades after someone pointed at him following a 1989 shooting death of a police officer in Savannah, Ga., stating he did it.

Davis was 19 at the time when he was accused of killing officer Mark MacPhail.

But Davis' supporters say he is an innocent man. They noted that 10 witnesses in the case have signed affidavits withdrawing their testimony and indicating that police coerced them into accusing the 41 year old.

The supporters also indicate that about nine people have signed affidavits implicating another man in the police murder, USA Today 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.'

For years the case has been attracting much attention. Many notables like former president Jimmy Carter, Pope Benedict XVI and Nobel laureate Desmond Tutu have urged authorities to spare Davis' life.

In today's world, where the Internet allows for rapid dissemination of information, it is a social media campaign to stop Davis' execution that is drawing much support from others around the world from celebrities, Nobel laureates and national leaders.

They have all joined the NAACP, Amnesty International and the grass-roots group to urge Georgia authorities to show mercy to Davis, according to USA Today, which reported that people are sending out several tweets a minute through Twitter, signing online petitions and planning  rallies across the globe.

On Thursday, the Georgia Board of Pardons and Paroles received petitions with 663,000 names urging clemency. The board will convene on Monday to consider the case.

The board is all that stands between Davis and what his supporters believe will be a wrongful execution. The board is made up of five members. Just a simple majority is needed to make a decision.

Laura Moye, the Death Penalty Abolition campaign director for Amnesty International USA, told the Agence France-Presse that a march was planned in downtown Atlanta at 6 p.m. on Friday, which will be followed by a service at Ebenezer Baptist Church, the spiritual center of the civil rights movement in the 1960s under Martin Luther King.

Moye also said rallies for Davis started earlier in Hong Kong. Those rallies went on throughout the day in the United States, Latin America, Europe and Asia. There were 10 events in France on behalf of Davis, Moye also told the AFP.

We hope the message they hear is that there is too much doubt in this case, Moye said. Can we even rely on the conviction of Troy Davis? Can we be sure we are not going to execute someone who is innocent?

American Civil Liberties Union attorney Tanya Greene also told AFP that the events will carry on over the weekend.

There is a great mobilization, this is more than I have known in recent history... because it's so clear that he was railroaded, the witnesses lied, she said. We have all the evidence now.