Section 740 ILCS 147/25 - Venue(a) In an action brought under this Act, venue shall lie in any county where an act charged in the complaint as part of a course or pattern of gang-related criminal activity was committed.(b) It shall not be necessary for all offenses necessary to establishing a course or pattern of criminal activity to have occurred in any one county where the State's Attorneys of several counties, or their designees, each complaining of any offense, elected to join in a complaint. In such instance, it shall be sufficient that the complaint, taken as a whole, alleges a course or pattern of gang-related criminal activity, and each count of any such joint complaint shall be considered as cumulative to other counts for purposes of alleging or demonstrating such a course or pattern of activity.(c) Where a course or pattern of activity is alleged to have been committed or to have occurred in more than one county, the State's Attorney of each such county, or their designees, may join their several causes of action in a single complaint, which may be filed in any such county agreed to by or among them, but no such joinder shall be had without the consent of the State's Attorney having jurisdiction over each offense alleged as part of the course or pattern of activity.