Maryland Criminal Law Section 3-403
(a)   A person may not commit or attempt to commit robbery under § 3-402 of this subtitle:
(1)   with a dangerous weapon; or
(2)   by displaying a written instrument claiming that the person has possession of a dangerous weapon.
(b)   A person who violates this section is guilty of a felony and on conviction is subject to imprisonment not exceeding 20 years.