Section 5904 - Subpoena of witnesses(a) Method of serviceIn addition to any other method of service provided by law, a subpoena may be served upon a witness in a criminal proceeding by registered or certified mail, return receipt requested, or by first class mail.(b) Proof of serviceA completed return receipt shall be prima facie evidence of service of the subpoena.(c) DurationA subpoena shall remain in force until the termination of the criminal proceeding.(d) Bench warrantsUpon proof of service of a subpoena, the court may issue a bench warrant for any witness who fails to appear in response to a subpoena. However, such warrant cannot be issued if service has been by first class mail.1978, Nov. 26, P.L. 1264, No. 301, § 3, imd. effective.