A family member of mine has a 17-year old son with a history of aggressive outbursts and impulse issues. He has threatened her, thrown things at her, destroyed public property (and got arrested for it), and has done other things I'm sure we don't know about. Apparently, this is not new behavior for him, since in kindergarten he drew a picture of one of his teachers hanging from a noose.

When his mother refused to let him see his girlfriend again (he had been sneaking over there and spending the night with her), he threw a knife at the wall and threatened to purchase a gun and shoot everyone ("everyone" being his mother, his mother's boyfriend, and his sister) before running away. This is all a shock to me because her son was always very polite and nice to me. Since they're several hours away from me there's nothing I can personally do, but what can I recommend for her to do in the current situation she's in? Would calling his parole officer and telling him/her that her son has gone missing help? She already tried talking to her ex-husband, but he's going on a business trip so he can't take him.