4 Pa. C.S. § 1519
A peace officer, licensee or licensee's security employee or an agent under contract with the licensee who has probable cause to believe that criminal violation of this part has occurred or is occurring on or about a licensed facility and who has probable cause to believe that a specific individual has committed or is committing the criminal violation may detain the suspect in a reasonable manner for a reasonable time on the premises of the licensed facility for all or any of the following purposes: to require the suspect to identify himself, to verify such identification or to inform a peace officer. Such detention shall not impose civil or criminal liability upon the peace officer, licensee, licensee's employee or agent so detaining.
4 Pa.C.S. § 1519