Honestly I'd just tread lightly around someone like that.

Simple fact of the matter is that scum bags like that cat always get what is coming to them... you just need to make sure you are inside when the sky falls to land on him.... ie.. don't try and catch him or mess with him... he'll get whats coming to him... the sherriff knows whats up.... he will no doubt get his shortly.

Sorry to hear about the trouble... nothing more frustraiting than bad neighbors.