Haw. Rev. Stat. § 806-87: Evidence at hearing on motion to dismiss.

(a) The defendant may introduce evidence at the hearing. The defendant may also subpoena and call witnesses if the motion is accompanied by a declaration stating that counsel for the defendant (or the defendant if appearing without counsel) has a good faith basis to believe that each witness subpoenaed will provide specific testimony to help demonstrate that the information and its exhibit or exhibits do not establish the existence of probable cause to believe that the offense charged has been committed or probable cause to believe that the defendant committed the offense charged.

(b) The court may, in its discretion, permit the State to call witnesses, introduce evidence, or otherwise supplement the exhibit or exhibits appended to the information.