Writ refused. the ruling of the trial judge is correct. A district attorney ad hoc has no authority to institute a new and different criminal prosecution against the defendant. Both Article 682 of the Louisiana Code of Criminal Procedure and the order of appointment are explicit on this point. Article 682 restricts the powers of the district attorney ad hoc to the cases in which he was appointed. The order of appointment provides: ". . . the said appointee shall act as district attorney ad hoc, in and for the parish of Orleans, with reference to these cases only . . ."