Nebraska Revised Statutes Chapter 29. Criminal Procedure § 29-1902. Return of subpoenas

If the subpoena be served by such special deputy, it shall be his duty, after serving the same, to return thereon the manner in which the same was served; and also to make oath or affirmation to the truth of such return, before some person competent to administer oaths, which shall be endorsed on such writ; and the same shall be returned according to the command thereof by the person serving the same through the post office or otherwise.