conduct unbecoming

i met a disturbing child today.
6 years old, emotionally detached, without empathy. hurts animals, punches and kicks his brothers. yet, seeing him in the office today, you'd never guess that he could be so disturbed. he was pleasant, smiling, behaved himself tolerably well. but there was also a coldness to the quality of his interactions, even with his dad and stepmother.
i asked his father if he ever cried, like when he fell down and scraped his knee or something. "no, never." his father replied.
this is a child with conduct disorder. at the age of 6, this is indicative of something terrible happening to him at a very young age.
the goal of treatment for this child is to keep him out of jail. that is what would be success for him. if he learns to empathize with other people, that would be a bonus.
i left work today with this heaviness in my heart. what happened to this boy to make him so insecure in his world?