HotRod Lincoln stole my answer. I say talk to a lawyer. This doesn't seem like too complicated of a situation, so it isn't like he'll be billing you for hours upon hours of work. The amount you save in both money and headache would make a legal professional well worth the up-front cost.
If you're not willing to deal with those bottom feeders, then make sure you talk to the police or go to small-claims court before you go nuts on the guy. There's no reason to go to jail on account of his being a jacka$$.
