The Criminal Investigation Division is under the direct command of Lieutenant Brian Cleary, a 21 year veteran of the Decatur Police Department.

The Criminal Investigations Division consists of a combined total of 50 sworn / civilian employees; responsible for the investigation of general crimes, vice crimes, juvenile crimes, covert investigative assignments, intelligence gathering, sex offender registration, fugitive apprehension and terrorism related criminal investigations.

The Criminal Investigations Division consists of three investigative branches; Adult Investigations Unit, Juvenile Investigations Unit and Street Crimes – Narcotics Unit. Providing intelligence to each of these units, as well as the Patrol Division, is the Crime Analysis Unit.