When I was 5 years old and starting kindergarten, I met another boy the same age who I quickly decided would end up in jail as an adult. He certainly wasn't the only one who misbehaved frequently or did cruel things to other children, but I could tell he was different somehow. He never seemed to need to feel justified in his cruelty.
In 1998, at age 19, he took part in a murder. He was sentenced to 20 years with 5 suspended. I think he's out on parole now.