I also have the drunk neighbor issue. Mine isn't really too agressive, but scary still. He comes in my yard when Im not home and bangs on the door to bother my dog (who hates him), and dig through my shed and take what he wants. Another neighbor alerted me to this behavior. I have since installed video cameras and put up signs.

It shows what alcohol can do to people. I hope the police do something about yours. Good luck with this. I know how frustrating it can be.