Maryland Criminal Law Section 4-303
(a)   Except as provided in subsection (b) of this section, a person may not:
(1)   transport an assault pistol into the State; or
(2)   possess, sell, offer to sell, transfer, purchase, or receive an assault pistol.
(b)   A person who lawfully possessed an assault pistol before June 1, 1994 and who registered the assault pistol with the Secretary of the State Police before August 1, 1994 may continue to possess the assault pistol.