Md. Code, Criminal Law § 6–409

(a) A person may not refuse or fail to leave a public building or grounds, or a specific part of a public building or grounds, during the time when the public building or grounds, or specific part of the public building or grounds, is regularly closed to the public if:

(1) the surrounding circumstances would indicate to a reasonable person that the person who refuses or fails to leave has no apparent lawful business to pursue at the public building or grounds; and

(2) a regularly employed guard, watchman, or other authorized employee of the government unit that owns, operates, or maintains the public building or grounds asks the person to leave.

(b) A person may not refuse or fail to leave a public building or grounds, or a specific part of a public building or grounds, during regular business hours if:

(1) the surrounding circumstances would indicate to a reasonable person that the person who refuses or fails to leave:

(i) has no apparent lawful business to pursue at the public building or grounds; or

(ii) is acting in a manner disruptive of and disturbing to the conduct of normal business by the government unit that owns, operates, or maintains the public building or grounds; and

(2) an authorized employee of the government unit asks the person to leave.

(c) A person who violates this section is guilty of a misdemeanor and on conviction is subject to imprisonment not exceeding 6 months or a fine not exceeding $1,000 or both.