I'm thinking of a movie.?

There's a movie I can't remember who was in it. It's a thriller about a black man who's in jail (maybe even on death row) and a defense attorney who thinks he's been wrongly accused is trying to get him off. The defense attorney used to be a prosecutor. I think it turned out the black man had been wrongly accused of and castrated several years ago and the attorney had something to do with it. If you have any info about this pick please let me know.