There was this one man who raped a little girl and killed her. When he was jailed, the prisoners sliced open his belly with a broken bottle then used his intestines to hang him. A rather barbaric execution if you ask me but he obviously since he'd killed that little kid, he didn't deserve to live. I also heard of another man who had also raped a little girl. He was raped by his fellow prisoners then stabbed more than 10 times.
Pedos and the like I believe get to pay for their crimes in kind when they're in prison.