The Fire Investigation Unit is composed of two teams of six firefighters and police officers, taking advantage of the specialized knowledge, training and skills of the respective public safety branches. The unit may be called to investigate any fire or bomb incident, especially any serious, fatal or questionable incident. Any fire or police supervisor may request the response of the unit.
The unit has at its disposal various pieces of equipment, including computers, evidence collection equipment, cameras, video recording equipment, lights, hand and power tools, vehicles and communication equipment. In addition, the unit may use the services of the state fire marshal; the Illinois State Police; the Bureau of Alcohol, Tobacco and Firearms; the Federal Bureau of Investigation and their associated forensic labs. The services of private sector engineers and investigators have also been used, as well as information from insurance companies.