The Attorney General shall investigate suspected criminal violations of this subtitle and may require assistance from any State’s Attorney for that purpose. The Attorney General shall commence and try all prosecutions under this subtitle with the State’s Attorney for the county where the prosecution is brought. With respect to the commencement and trial of the prosecution, the Attorney General has all the powers and duties vested by law in State’s Attorneys with respect to criminal prosecutions. A prosecution for any offense in violation of this subtitle shall be commenced within four years after the offense is committed. The Attorney General may not commence prosecution under this subtitle against any person while the person is a defendant with regard to a pending complaint, information, or indictment which: Involves substantially the same subject matter; and Is filed by the United States for violation or alleged violation of the federal antitrust statutes, including the statutes enumerated in § 11-202 and any similar act passed in the future.