Md. Code Ann., Cts. & Jud. Proc. § 5-612

The police officers and other officers, agents, and employees of any county or municipal corporation, when acting under the authority of § 2-105 of the Criminal Procedure Article or other lawful authority, beyond the territorial limits of the county or municipal corporation within the State shall have all the immunities from liability enjoyed by them while performing their respective duties within the territorial limits of the county or municipal corporation.