The Franklin Park Fire Department operates a Fire Investigation Unit (F.I.U).  The FIU is responsible for investigating all suspicious fires, fires where there is a large loss, and fires involving injuries or fatality within the Village of Franklin Park.

The FIU is also responsible for the Juvenile Firesetter's Program.  This program was established to combat the growing problem of juveniles who start fires or display an unusual curiosity of fire.

The FIU is an active part of the MABAS Division 20 Fire Investigation Team.  This team is made up of members from most fire departments and a few police departments within the Division 20 surrounding communities.  This team responds to all requests for assistance from any department that may need help with investigating a fire in their community.

Currently, the FIU has four members consisting of Lt. Jack Berry, Lt. William Brehm, Firefighter Nick Steker and Firefighter Douglas Halverson.  All members are Certified Fire Investigators in the State of Illinois, as well as State Certified in the Juvenile Firesetter's Program.