(a) The Department has the power to appoint, subject to the Personnel Code, persons to be members of a police and security force. Members of the police and security force shall be peace officers and as such have all powers possessed by policemen in cities and sheriffs, including the power to make arrests on view or on warrants of violations of State statutes or city or county ordinances. These powers may, however, be exercised only in counties of more than 500,000 population when required for the protection of Department properties, interests, and personnel or when specifically requested by appropriate State or local law enforcement officials. Members of the police and security force may not serve and execute civil process.
     (b) The Director must authorize to each member of the police and security force and to any other employee of the Department exercising the powers of a peace officer a distinct badge that, on its face, (i) clearly states that the badge is authorized by the Department and (ii) contains a unique identifying number. No other badge shall be authorized by the Department.