C.R.S. § 19-3-504

(1) Any person summoned or required to appear as provided in section 19-3-503 who has acknowledged service and fails to appear without reasonable cause may be proceeded against for contempt of court. (2) If after reasonable effort the summons cannot be served or if the welfare of the child requires that he be brought immediately into the custody of the court, a bench warrant may be issued for the respondent or for the child.