Any person granted the powers enumerated in this subsection (a) may exercise such powers only during the actual investigation of the cause, origin and circumstances of such fires or explosions that are suspected to be arson or arson-related crimes.
For purposes of this subsection (b), a "State Fire Marshal Arson Investigator Special Agent" does not include any fire investigator, fireman, police officer, or other employee of the federal government; any fire investigator, fireman, police officer, or other employee of any unit of local government; or any fire investigator, fireman, police officer, or other employee of the State of Illinois other than an employee of the Office of the State Fire Marshal assigned to investigate arson.
The State Fire Marshal must authorize to each employee of the Office of the State Fire Marshal who is exercising the powers of a peace officer a distinct badge that, on its face, (i) clearly states that the badge is authorized by the Office of the State Fire Marshal and (ii) contains a unique identifying number. No other badge shall be authorized by the Office of the State Fire Marshal, except that a badge, different from the badge issued to peace officers, may be authorized by the Office of the State Fire Marshal for the use of fire prevention inspectors employed by that Office. Nothing in this subsection prohibits the State Fire Marshal from issuing shields or other distinctive identification to employees not exercising the powers of a peace officer if the State Fire Marshal determines that a shield or distinctive identification is needed by the employee to carry out his or her responsibilities.
20 ILCS 2910/1