There are several different issues here:1) First, it's not automatically a given that they can ask your son to not return. If the lease itself does not state that people may be evicted for criminal convictions, then they probably cannot make him go--the lease is a contract, and binds both parties (landlord and tenant); the landlord cannot add new requirements or terms. So unless the lease provides for eviction in this case, your son probably does not need to go. (Exception: if he committed crimes against the landlord, they could evict him.)2) If you have to give 60 days notice, then you need to provide 60 days notice--i.e. pay rent for a period of time. If you son is on the lease, you may be able to argue that by evicting one person on the lease, they are effectively evicting you, too, thought it's not certain that would be winning argument; however, if he's not on the lease, there is no doubt but that they could evict him while still holding you to the 60-day notice.