Conn. Gen. Stat. § 52-486: Mandamus. Return. Judgment for costs.

When the party to whom a writ of mandamus is directed makes a return sufficient on its face and the return is denied by the other party, the court shall inquire into the truth of the return. If the return is found untrue, the court may issue a peremptory mandamus in the same manner and on the same principles as if the return were insufficient, and may render judgment for the complainant to recover his costs, and grant execution for such costs. If the return is found to be true and sufficient, the court may render judgment for costs in favor of the party complained of.