16 Pa. Stat. § 7710
If any district attorney, within this commonwealth, shall neglect or refuse to prosecute, in due form of law, any criminal charge, regularly returned to him, or to the court of the proper county; or if, at any stage of the proceedings, the district attorney of the proper county, and the private counsel, employed by the prosecutor, should differ as to the manner of conducting the trial, it shall be lawful for the prosecutor to present his or her petition to the court of the proper county, setting forth the character of the complaint, and verify the same by affidavit; whereupon, if the court shall be of the opinion that it is a proper case for a criminal proceeding or prosecution, it shall be lawful for it to direct any private counsel, employed by such prosecutor, to conduct the entire proceeding, and where an indictment is necessary, to verify the same, by his own signature, as fully as the same could be done by the district attorney; and this act shall apply to all criminal proceedings heretofore commenced, and still pending, as well as to those which shall be instituted hereafter.
16 P.S. § 7710