(720 ILCS 5/31-4)(from Ch. 38, par. 31-4) Sec. 31-4. Obstructing justice. A person obstructs justice when, with intent to prevent the apprehension
or obstruct the prosecution or defense of any person, he knowingly commits
any of the following acts: (a) Destroys, alters, conceals or disguises physical evidence, plants
false evidence, furnishes false information; or (b) Induces a witness having knowledge material to the subject at issue
to leave the State or conceal himself; or (c) Possessing knowledge material to the subject at issue, he leaves the
State or conceals himself. (d) Sentence. (1) Obstructing justice is a Class 4 felony, except
as provided in paragraph (2) of this subsection (d).
(2) Obstructing justice in furtherance of streetgang
related or gang-related activity, as defined in Section 10 of the Illinois Streetgang Terrorism Omnibus Prevention Act, is a Class 3 felony.