William Petersen has revealed that he was able to leave CBS's Csi Crime Scene Investigation without his character being killed off after being promised a role in a movie version of the hit series. In an interview with the London Daily Telegraph , Petersen said, "I'd love to see us make a CSI film. That's the reason Grissom [his character] isn't going to die of a brain tumor." Petersen indicated that the movie may be coming soon. Noting that such films are usually produced after a series completes its TV run, Petersen said, that will not be the case with a CSI movie. "It's about finding the right story -- there has got to be a real reason to do it. You don't just do it because you want to make money, you do it because there's a story that can't be told on TV and needs to be told from CSI 's perspective and the audience wants it. And we can't wait for CSI to end of Grissom will be about 90."