Oscar-winning actress Susan Sarandon is on a mission to help save an inmate's life.

The 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 the film "Dead Man Walking" - is seeking to stay the execution of death row inmate Richard Glossip, 52.

"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, 68, told people.com.

Glossip was arrested in 1997 for killing a man named Barry Van Treese, who was beaten to death with a baseball bat in an Oklahoma motel. 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, according to The Washington Post.

After striking a plea deal, Sneed received a life term in prison without parole, while Glossip was sentenced to death in 1988.

"Since the only real option we had is press, because (Glossip) has gone through a number of trials and has exhausted that route, I decided to help," said Sarandon.

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 to receive a lethal injection on September 16, to live.