A. In addition to other student discipline policies, each school district shall adopt a policy providing for the expulsion from school, for a period of not less than one year, of any student who is determined to have knowingly brought a weapon to a school under the jurisdiction of the local board. The local school board or the superintendent of the school district may modify the expulsion requirement on a case-by-case basis. [...]
C. For the purposes of this section, "weapon" means:
(1) any firearm that is designed to, may readily be converted to or will expel a projectile by the action of an explosion; and
(2) any destructive device that is an explosive or incendiary device, bomb, grenade, rocket having a propellent charge of more than four ounces, missile having an explosive or incendiary charge of more than one-quarter-ounce, mine or similar device.