physical evidence found linking him to the murder, the conviction relied heavily on the testimony of justin snooed, the man who confessed to the actual murder and is currently serving a life sentence in prison. >> reporter: sister helen has been at the poreforefront. >> you think richard is innocent, yes? >> yeah. >> why? >> there's no forensic evidence at all to implicate him. >> reporter: the film version of her book "dead man walking." sarandon herself has taken up this cause. >> he's a perfect example of what's wrong with the death penalty. he's clearly innocent. and on top of that, the guy who actually killed the person is in a minimum security prison for the rest of his life. >> reporter: sarandon brought the story to "the dr. phil show" to garner support, breaking down after reading a letter he wrote. >> it's very upsetting. you believe that if you're unjustly accused that people will realize it and it's just -- i'm heartbroken for the state of our judicial system as much as i'm heartbroken for this man. >> reporter: his family maintains he was set up, and that the prosecution failed to sho