16 Pa. C.S. § 14309
If a district attorney neglects or refuses to prosecute in due form of law a criminal charge regularly returned to the district attorney or to the court or if at any stage of the proceedings the district attorney and the private counsel employed by the prosecutor differ as to the manner of conducting the trial, the prosecutor may present a petition to the court, specifying the character of the complaint, and verify the petition by affidavit. If the court is of the opinion that it is a proper case for a criminal proceeding or prosecution, the court may direct a private counsel employed by the prosecutor to conduct the entire proceeding and, if an indictment is necessary, to verify the indictment by the private counsel's own signature as fully as the indictment could be done by the district attorney.
16 Pa.C.S. § 14309