I suggest that you send a letter to the school board and principle and ask for a copy of the student dsicplinary policy that addresses this kind of behavior. You may also want to copy your local police chief. If there is no policy or no enforcement or they refuse to enforce the policy you should contact the Illinois State Board of Education. I have pasted the statute below. Good luck.
105 ILCS 5/10-20.14
Sec. 10-20.14. Student discipline policies; Parent-teacher advisory committee.
(d) The school board, in consultation with the parent-teacher advisory committee and other community-based organizations, must include provisions in the student discipline policy to address students who have demonstrated behaviors that put them at risk for aggressive behavior, including without limitation bullying, as defined in the policy. These provisions must include procedures for notifying parents or legal guardians and early intervention procedures based upon available community-based and district resources.
(Source: P.A. 91-272, eff. 1-1-00; 92-260, eff. 1-1-02.)