My kids' school district has a Parent/Student Handbook that has a "Weapons" section that reads as follows:
A student who uses, possesses, controls, or transfers a weapon, or any object that can reasonably be considered, or looks like, a weapon, shall be expelled for at least one calendar year, but no more than two calendar years. The Superintendent may modify the expulsion period and the School Board may modify the Superindentent's determination, on a case-by-case basis. A "weapon" means possession, use, control, or transfer of: (1) any gun, rifle, shotgun, a weapon as defined by Section 921 of Title 18, United States Code, firearm as defined in Section 1.1 of the Firearm Owners Identification Act, or use of a weapon as defined in Section 24-1 of the Criminal Code, (2) any other object if used or attempted to be used to cause bodily harm, including but not limited to, knives, brass knuckles, billy clubs, or (3) "look-alikes," of any weapon as defined above. Any items such as a baseball bat, pipe, bottle, lock, stick, pencil, and pen is considered to be a weapon if used or attempted to be used to cause bodily harm. The Building Principal or designee shall notify the criminal justic or juvenile delinquency system of any student who brings a firearm or weapon to school."
Section 921 of Title 18 of United States Code (firearms only):
http://caselaw.lp.findlaw.com/casecode/uscodes/18/parts/i/chapters/44/sections/section_921.html Illinois Firearm Owners Identification Card Act (firearms only):
http://www.ilga.gov/legislation/ilcs/ilcs3.asp?ActID=1657&ChapAct=430 ILCS 65/&ChapterID=39&ChapterName=PUBLIC+SAFETY&ActName=Firearm+Owners+Identification+Card+Act.
Illinois Criminal Code, Section 24-1 (this one related to knives):
http://law.onecle.com/illinois/720ilcs5/24-1.html