Conn. Gen. Stat. § 14-148: Abandoned markers.

(a) Any person who has found, or has in his possession, any number plate or number plates, or identifying part thereof, currently in use, which plate or plates were not issued to him, shall immediately deliver the same to the commissioner or to any officer. Such officer shall, within twenty-four hours, notify the commissioner that he holds such number plate or number plates or identifying part thereof to his order.

(b) Any officer may remove any number plate or number plates from any motor vehicle when such motor vehicle is apparently abandoned or when such number plate or number plates have been or are being used illegally and shall forward them to the commissioner with a statement of the reason for such removal.

(c) Violation of any provision of subsection (a) of this section shall be an infraction.