Legal Question in Real Estate Law in Maryland

The tenant is in breach of the lease if they vacate before it terminates, so you are entitled to those 3 months from them, unless there was a provision in the lease allowing them to vacate early in certain situations. . However, you have a duty to try and find a replacement tenant who might possibly move in during those last 3 months. If so, you'd be entitled to whatever months you lost plus the money you paid the realtor to find a new tenant. So you can use the security deposit to offset those losses, assuming you don't incur additional expenses occasioned by the condition in which the tenant leaves the premises. You need to follow the procedure set up in the landlord tenant law regarding an inspection of the premises and notice of damage to the tenant in order to properly withhold the security deposit. Incidentally, it's unusual to pay a realtor in advance like you did--usually a fee is taken from the first month's rent once they find a new tenant.