In my state if someone has been living at a residence for a short amount of time (forget exact number but isn't long) it is considered their residence and they pretty much have to be evicted to get them out. Like the formal eviction process.
Here is to hoping and praying that he just leaves. Maybe if you did have the cops around that would just freak him out enough to leave.
I'm sorry you are in this situation. Good luck and stay strong!