Hello,
Maryland has a law that protects tenants who cannot "enjoy" their property. Please review the article at the following:
Constructive Eviction and Right to Quiet Enjoyment
Here is another article:
Breaking your lease.
You should submit a complaint in writing about the necessity for better locks. This will be helpful when you decide to move out.
It is difficult to break a lease in the state of Maryland, but you have good grounds. Also, the landlord is required to try to rent the apartment right away so no rent in lost.
Good luck to you.
Lawyer (JD)
Juris Doctorate Degree