I rent an apartment in Rhode Island with one roommate. Her boyfriend has been staying here for months now, claiming it's temporary, but he keeps pushing back the date he plans to leave (currently it's vague...sometime in the future). Although he has not been paying any rent (seeing as he's a "visitor") he just decided to start paying my roommate half of her rent (he's not paying the landlord--just chipping in to my roommate for her half).
He has moved all of his belongings into our apartment. Our lease specifies that no other tenants may live there who are not on the lease (only me and my roommate). My roommate argues that she pays half the rent and can have whatever guests she likes stay with her. Our lease does not specify what length of time is "living" there versus "visiting," so I don't know what argument can be made there, but it has been going on for months with an indefinite future.
Furthermore, the boyfriend has threatened me before (including to beat me up) when I have done things that he or his girlfriend, my roommate, did not like. I probably should have contacted the police right after those times, but I guess I didn't put much stock in them at the time. It's been a while since that has happened, so I do not know if that makes a difference.
What can I do? I have hesitated to contact my landlord, as my impression is that he'd rather have nothing to do with it as long as the rent gets paid. Should I contact him and see if eviction would be possible? Or should I contact the police first?