Conn. Gen. Stat. § 54-56b: Right to dismissal or trial on nolle.

A nolle prosequi may not be entered as to any count in a complaint or information if the accused objects to the nolle prosequi and demands either a trial or dismissal, except with respect to prosecutions in which a nolle prosequi is entered upon a representation to the court by the prosecuting official that a material witness has died, disappeared or become disabled or that material evidence has disappeared or has been destroyed and that a further investigation is therefore necessary.