Md. Code, General Provisions § 4–339

(a) Except as provided in subsection (b) of this section, a custodian shall deny inspection of the part of a public record that identifies or contains personal information about a person, including a commercial entity, that maintains an alarm or security system.

(b) A custodian shall allow inspection by:

(1) the person in interest;

(2) an alarm or security system company if the company can document that it currently provides alarm or security services to the person in interest;

(3) law enforcement personnel; and

(4) emergency services personnel, including:

(i) a career firefighter;

(ii) an emergency medical services provider, as defined in § 13–516 of the Education Article;

(iii) a rescue squad employee; and

(iv) a volunteer firefighter, a rescue squad member, or an advanced life support unit member.