okay, here's how to resolve the situation in a non-violent way.
Throw away his bong, pot, and hide his knife.
Lock your door and cover it with Styrofoam or egg shell cartons, this way his consistent jack-assery will be quieted down and you can get some rest.
Next is Black-Mail, threaten him that you will tell his girlfriend he was cheating with proof of PHOTOS. If that doesn't work say you'll report him to the police for his knife or the pot.