Looking for an older prison film?

Hello, I've been looking for a movie for so long and I just can't find it.

It's about a man whose wife is murdered. He pursues the man until she is stopped by the police. He is acquitted at trial because the murderer's father is a politician. He kills the man in court. In prison, the man is beaten and trains every day; a butterfly appears to him and flies into his cell. He befriends a black man and they plan to escape. Unfortunately, the black man is murdered but the man whose wife was murdered managed to escape. I would be grateful if someone could help me.

Best regards.