Leaving tenant wouldn't let me in and wants to use security deposit for rent

[Natalia Perlova]

Hi BP Fam, 

I would love to get your advise on the following situation: tenant (rent by the room) notified me that he's leaving at the end of July, great. But then he told me that i can not show his room to potential tenants because he's "packing and has sensitive documents". Now he has not paid the rent, and wants to use the security deposit for that. The lease clearly states that i can access the property and security deposit cannot be applied to cover last month. He also parks in the back without paying for parking. The unit is rent by the room, but he installed a lock on his door. 

What would you do? Is it worth it to get a lawyer if he's on his way out?
Thank you!

[Colleen F.]

@Natalia Perlova I would issue a pay or quit notice since he has not paid rent, even though he says he is leaving going through the process in case he doesn't. He is using his security deposit which you told him he could not do.  I would also arrange an inspection and issue a repair bill for any issues like lock removal. Looks like you are in Massachusetts so there are specifics related to security deposits.