Williamson County Sheriff's Office


Williamson County Sheriff's Office

Williamson County Sheriff's Office
404 N. Van Buren
Marion, IL  62959
Tx:  618-997-6541
Office Fax:  618-998-2296
Dispatch Fax:  618-997-1301


Jeff Diederich, Sheriff

The Williamson County Major Case Squad was created in 1993 as a way to focus law-enforcement efforts during the investigation of a major crime.

The Major Case Squad is made up of investigators and officers from the Williamson County Sheriff's Office, Illinois State Police, and the municipalities in Williamson County.

The premise behind the inception of the Major Case Squad is to bring together specially trained, extremely motivated and highly experienced investigators from around the Williamson County area to aggressively investigate major crimes.  During the tenure of the Major Case Squad it has been so successful in solving these major crimes, it averages nearly an 80% clearance rate.  During a Major Case Squad call-out between 15 to 25 investigators, from all different departments, will respond to the command post within three hours of the discovery of the crime bringing a wealth of law enforcement knowledge and experience.  The Major Case Squad is also highly specialized in new and advanced investigative techniques.

The Major Case Squad is activated at the request of the department that has primary jurisdiction over the crime.

Sheriff Jeff Diederich


The Criminal Investigation Division (CID) of the Williamson County Sheriff's Office is commanded by Lieutenant Karl Gusentine.

The division consists of a squad of criminal investigators (detectives) that do follow-up investigations on crimes such as homicide, rape, robbery, burglary and forgery. The squad has 4 criminal investigators.