The department may issue separate licenses to security alarm system contractors, private college security forces, private security police, and private security guard agencies. This section does not prevent a private detective or private investigator licensed under the professional investigator licensure act, 1965 PA 285, MCL 338.821 to 338.851, from performing the services of a private security guard or private security police except that a private security guard or private security police may not perform the services of a private detective or private investigator without obtaining a private detective or private investigator license.