Md. Code, Criminal Procedure § 2–205

A police officer without a warrant may arrest a person if:

(1) the police officer has probable cause to believe the person has engaged in stalking under § 3-802 of the Criminal Law Article;

(2) there is credible evidence other than the statements of the alleged stalking victim to support the probable cause under item (1) of this section; and

(3) the police officer has reason to believe that the alleged stalking victim or another person is in danger of imminent bodily harm or death.