The 68-year-old actress, who won an Oscar for her portrayal of Sister Helen Prejean, a real-life nun who grows close to a man on death row, in "Dead Man Walking", is on a crusade to help save the inmates life, reported People Magazine.
"Sister Helen Prejean called me and convinced me that this guy, Richard Glossip, was innocent and needed another chance to have better representation to present new information that would establish a reasonable doubt as to his guilt and save him from being executed," Sarandon said.
A man named Justin Sneed confessed to the murder, but told investigators that Glossip, the motel's handyman at the time, paid him to commit the murder. Glossip was sentenced to the death penalty in 1988.
In addition to signing her own name on petitions on websites like MoveOn.Org and change.Org, Sarandon has helped amass more than 150,000 signatures from people hoping to convince Oklahoma Governor Mary Fallin to allow Glossip, who is scheduled for lethal injection on September 16, to live.