D.C. Code § 16-3103: Summons; failure to appear or give evidence.

A summons issued by the Probate Court to a person concerned in the affairs of a deceased person, or to a witness or other person whose appearance in the court is deemed necessary or proper, is returnable at the discretion of the court. When it is necessary or proper on the return of the “summoned”, and failure of the person to appear, to enforce his appearance, or when a witness before the court refuses to give evidence, the court may exercise its contempt power, or it may have his estate, or a part thereof attached and sequestered as provided by section 16-3104 .