Legal Question in Real Estate Law in Maryland

Re: lease

Legally, if he is on the lease he has the right to be in the premises until the lease is expired. However, if he has stopped paying the rent, you should send him a letter or email saying that if he doesn't immediately refrain from entering the premises, you intend to sue him for half the rent since he stopped paying. You can go to court and request a peace order, or if there has been some threat of violence against you, a civil protection order.

You could ask the landlord for permission to change the locks if you want to bear that expense, but if you're planning on leaving in November, that doesn't sound like a good investment.