Md. Code, Public Safety § 5–121

(a) On receipt of a firearm application, the Secretary shall conduct an investigation promptly to determine the truth or falsity of the information supplied and statements made in the firearm application.

(b) In conducting an investigation under this subsection, the Secretary may request the assistance of the Police Commissioner of Baltimore City, the chief of police in any county maintaining a police force, or the sheriff in a county not maintaining a police force.