Out of control child: How to tell the parents I think he needs professional help?

Wow, that really sucks. That poor kid, obviously something pretty tragic has happened in his life that he is keeping bottled up. The best advice that I can think of is persistence. Start making nonchalant comments to the mother AND the father everyday. Hopefully one of them will take the hint and start listening to you. I hope it all works out for you and for the boy.