The Fire Investigation Unit (A/FIU) conducts investigations of major alarm fires and other fires when mandated by Department policy. In addition, the FIU investigates those fires that appear to be of significance in Fire Prevention practices. They interview witnesses, collect and preserve evidence, write reports and maintain comprehensive files on fires investigated, and conduct training programs for Departmental personnel.

As part of their duties and as a consequence of their investigations, FIU personnel are required to testify in both criminal and civil court cases. Because some fires investigated are of suspicious origin, this unit must work very closely with the Sheriff’s Arson/Explosive Unit as well as other law enforcement agencies. The FIU is responsible for arson and criminal investigations in 15 cities. It is also necessary for this Unit to work with representatives of other fire departments; State Fire Marshal’s Office; State of California Resources Agency Departments of Forestry (CDF); United States Forest Service (USFS); Consumer Product Safety Commission; National Fire Protection Association; Alcohol, Tobacco, and Firearms, arson task forces, insurance industries, and private investigators. This unit is staffed by one Captain and seven Investigators. The unit also has an Accelerant Detection Canine Team comprised of a trained dog and handler.