“Peace officer” means (i) any person who by virtue of his office or public employment is vested by law with a duty to maintain public order or to make arrests for offenses, whether that duty extends to all offenses or is limited to specific offenses, or (ii) any person who, by statute, is granted and authorized to exercise powers similar to those conferred upon any peace officer employed by a law enforcement agency of this State.
     For purposes of Sections concerning unlawful use of weapons, for the purposes of assisting an Illinois peace officer in an arrest, or when the commission of any offense under Illinois law is directly observed by the person, and statutes involving the false personation of a peace officer, false personation of a peace officer while carrying a deadly weapon, false personation of a peace officer in attempting or committing a felony, and false personation of a peace officer in attempting or committing a forcible felony, then officers, agents, or employees of the federal government commissioned by federal statute to make arrests for violations of federal criminal laws shall be considered “peace officers” under this Code, including, but not limited to, all criminal investigators of:
         (1) the United States Department of Justice, the