Conn. Gen. Stat. § 29-19
Special police officers for utility and transportation companies. Special police officer for the Connecticut Airport Authority.
(b) The commissioner may, upon the application of any railroad, express company or steamboat company, engaged in the business of transportation in this state, or upon the application of any corporation owning or having control of the roads in any private residence park, or upon the application of the Connecticut Airport Authority, commission, during the commissioner's pleasure, one or more persons designated by such company or by such corporation, or one person designated by such authority, who, having been sworn, may act, at the expense of such company, corporation or authority, as a police officer or police officers, as the case may be, upon the premises used by such company or authority in its business, or upon its cars, vessels or airplanes, or upon the roads and land owned by or under the control of such corporation or authority, and each police officer so appointed may arrest and take before some proper authority any person in the police officer's precinct for any offense committed therein. When any such commission is issued or revoked, the commissioner shall notify the clerk of the superior court for each judicial district in which it is intended that such police officer shall act. Each such police officer shall, when on duty, wear in plain view a shield bearing the words “railroad police”, “steamboat police”, “express company police” or “special police”, as the case may be, and the name of the company, corporation or authority for which the police officer is commissioned.
See Sec. 25-44 re appointment of special police for protection of water supplies.