(a) A judge may refer to a magistrate any matter arising out of a criminal case involving:
(1) a negotiated plea of guilty or nolo contendere before the court;
(2) a bond forfeiture;
(3) a pretrial motion;
(4) a postconviction writ of habeas corpus;
(5) an examining trial;
(6) an occupational driver's license;
(7) an appeal of an administrative driver's license revocation hearing; and
(8) any other matter the judge considers necessary and proper.
(b) The magistrate may not preside over a trial on the merits, whether or not the trial is before a jury.