need help for my father, he has been living in a rent control apt for the last 30 years had kids there. But his name was not on the lease, originally he was sharing cost with a roommate making playment via bank checks, and that just continued even when his roommate moved out. Now the LL is changing keys on the building and will not give keys to my father because he does not have "proof" that he is living there and his name is not on any lease. He is 75years old and scared. We have birth certificates with the address, taxes filed at that address and years of bills under his name.... what can he do? PLEASE HELP...