(A) Whoever enters upon land supported in whole or in part with state funds, or federal funds administered or granted through state agencies or any building on the land, after receiving, immediately prior to the entry, notice from the state or its representative that the entry is forbidden, or remains upon the land or in the building after receiving notice from the state or its representative to depart, and who interferes with another person's lawful use or enjoyment of the building or land, commits a misdemeanor.
(B) A person has received notice from the state within the meaning of division (A) of this section if he or she has been notified personally, either orally or in writing, or if a printed or written notice forbidding an entry to him or a group of which he is a part, has been conspicuously posted or exhibited at the main entrance to the land or the forbidden part thereof.
(C) Whoever enters upon land supported in whole or in part with state funds, or federal funds administered or granted through state agencies or any building on such land by presenting false documents or falsely representing his or her identity orally to the state or its representative in order to obtain permission from the state or its representative to enter the building or land; or remains upon such land or in such building by presenting false documents or falsely representing his or her identity orally to the state or its representative in order to remain upon such land or in such building, and who thereby interferes with another person's lawful use or enjoyment of such building or land, commits a Class A misdemeanor.
(D) Division (C) of this section does not apply to a peace officer or other official of a unit of government who enters upon land supported in whole or in part with state funds, or federal funds administered or granted through state agencies or any building on such land in the performance of his or her official duties.
(ILCS Ch. 720, Act 5, § 21-5) Penalty, see § 130.99