Former FBI Director William S Sessions is calling on the state of Georgia to halt the execution of death row inmate Troy Davis.

Davis was convicted of the murder of a Savannah, GA police officer back in 1991 and was recommended for execution by jury. Since that trial, however, seven of the nine witnesses called by the prosecution have either taken back their testimonies or altered their stories. Coupled with the lack of a murder weapon and physical evidence linking Davis to the crime, activists have long protested his persecution and continue to rally for his innocence.

It’s been a long two decades for Davis on death row, and with the execution slated to occur in mere days, activists have stepped up to speak about his innocence. Along with Pope Benedict XVI and former President Jimmy Carter, Sessions is the latest of high-profile personalities to speak up for Davis’ freedom.

"Serious questions about Mr. Davis' guilt, highlighted by witness recantations, allegations of police coercion and a lack of relevant physical evidence, continue to plague his conviction," Sessions writes in an editorial published to the Atlanta Journal-Constitution Thursday. He adds that "pervasive, persistent doubts" exist regarding the supposed guilt of Davis, and that the execution, scheduled for September 21 at 7 pm, should be stopped.

Sessions served Director of the FBI under Presidents Ronald Regan, George HW Bush and Bill Clinton.

Activist Deirdre O'Connor has joined the ranks of Carter, Sessions and the rest in her support of Davis. Speaking to RT earlier this year, O’Connor said the case is an example of the court system searching out for a guilty party at all costs, regardless of innocence.

“It becomes less about who did it and less about the search for truth, and more about holding someone accountable,” O’Connor said to RT. She added that “because people of African descent and minorities and people who don’t have money are treated as expendable, it doesn’t matter if we get to the truth.”

More than 100 events are slated to take place internationally on Friday of this week as activists gather across the world to rally in support of Davis. More than a thousand are expected to attend a march in Atlanta, GA led by the NAACP, CBS News reports.