As the hour of Davis execution nears, calls for clemency grow louder.

The scheduled execution of Georgia death row inmate Troy Davis is just hours away as I write this. As the appointed time of 7 p.m. approaches, protests are mounting and calls for clemency are growing louder here in the United States and around the globe.

Davis, 42, was convicted of the 1989 killing of off-duty police officer Mark MacPhail. Representatives of the NAACP, Amnesty International, along with Pope Benedict XVI and former President Jimmy Carter are among those who have called for a halt to the execution of Davis. Davis has steadfastly maintained his innocence and his conviction came despite a lack of physical evidence and the failure to find the murder weapon. In addition, a key witness subsequently recanted his testimony. The murdered police officer's family members maintain that prosecutors had the right man and Davis is not innocent.

Is Georgia planning to execute an innocent man? I don’t know the answer to that question. I do know that there have been instances where inmates under the sentence of death have been exonerated due to DNA evidence. The Innocence Project maintains a searchable database of such individuals. Established in 1992at the Benjamin N. Cardozo School of Law at Yeshiva University, The Innocence Project lists its mission as “nothing less than to free the staggering numbers of innocent people who remain incarcerated.”

The National Criminal Justice Reference Service also provides some numbers that give one pause. In addition to statistics about the demographic characteristics of death row inmates, the average elapsed time between sentencing and execution and the method of execution in individual states the agency also provides data about the number of people who have been removed from the list. Why were they removed: Some were executed, some died of natural causes while on death row, some had their sentences commuted and still others were exonerated.

Perhaps the most chilling resource I discovered was a list maintained by the Death Penalty Information Center, a non-profit organization established in 1990 to provide the media and the public with analysis and information on issues concerning capital punishment. They maintain a list of the "Executed but Possibly Innocent" that details the case against the individuals, their conviction, and execution. It also provides links to court documents, journal articles and media reports related to those cases.

The above photo of Troy Davis comes from Amnesty International.