§ 135.02 REFUSING TO AID AN OFFICER.
   No person, upon command, shall refuse or knowingly reasonably fail to aid a person known by him to be a police officer in:
   (A)   Apprehending a person whom the officer is authorized to apprehend; or
   (B)   Preventing the commission by another of any offense.
(ILCS Chapter 720, Act 5, § 31-8) Penalty, see § 130.999