Hawaii Revised Statutes Division 5. Crimes and Criminal Proceedings § 835-3

(a) A proceeding to adjudge a person a material witness must be commenced by application to the appropriate court, made in writing and subscribed and sworn to by the applicant, demonstrating reasonable cause to believe the existence of facts, as specified in section 835-2(a), warranting the adjudication of the person as a material witness.

(b) If the court is satisfied that the application is well-founded, the prospective witness may be compelled to appear in response thereto as follows:

the court may issue a warrant addressed to a police officer, directing the officer to take the prospective witness into custody within the State and to bring the prospective witness before the court forthwith in order that a proceeding may be conducted to determine whether the prospective witness is to be adjudged a material witness.