They don't mention the teen's parents in the story. What sticks to my mind is something we learned in school long ago...."violence begets violence". I'm sure this teen didn't learn this stuff by himself, sounds like he might have ben slammed around as a child himself. Nurtured kids never act this way , not that I've witnessed at least. But I have witnessed neglected, abused kids who are now acting out in the same way as adults.