The hearing provided for pursuant to §§ 37.2-814 through 37.2-819 may be conducted by the district court judge or a special justice at the convenient facility or other place open to the public provided for in § 37.2-809, if he deems it advisable, even though the facility or place is located in a county or city other than his own. In conducting such hearings in a county or city other than his own, the judge or special justice shall have all of the authority and power that he would have in his own county or city. A district court judge or special justice of the county or city in which the facility or place is located may conduct the hearing provided for in §§ 37.2-814 through 37.2-819.