FIAT began in the 1970s as a group of small police departments in DuPage County, Illinois, identified the need to pool detectives for major investigations. Smaller law enforcement agencies having only a few detectives needed to "borrow" more investigators for crimes such as murder, sexual assault, robbery, or burglary. When FIAT began, all the chiefs of police (and the DuPage Co Sheriff) signed a mutual aid agreement which formalized the process of requesting additional detectives. With a single telephone call, a process to gather these detectives could be underway.