Trivia

Director Larry Cohen wanted to film at various authentic locations but was repeatedly turned down for permission. However, when First Lady Betty Ford - a former dancer - found out that Dan Dailey was in Washington to make a film, she invited him and Broderick Crawford to the White House for lunch, as she had always liked Dailey's films and work. Larry Cohen then started calling locations such as the FBI's training facility in Quantico, Virginia, and said that he wanted to film there but couldn't do so the next day because the cast was having lunch at the White House. Every location, likely supposing that the film had official backing, soon made themselves available.

Several people who were real-life acquaintances of J. Edgar Hoover are featured in the film, including the barber who regularly cut his hair and his regular waiter at the Mayflower Hotel.

The film was shot at authentic locations such as J. Edgar Hoover's office and home, the FBI's headquarters in Washington, DC, and training facility in Virginia, and the Mayflower Hotel (where Hoover ate lunch daily).

The film had a formal screening at the Kennedy Center, but members of both parties in the largely political audience were irritated by the film's unflattering depiction of not only Republicans such as Richard Nixon, but also Democrats such as the Kennedys and Franklin D. Roosevelt.

According to Larry Cohen, in a 1997 interview with Creative Screenwriting Magazine, the insurance company refused coverage for actor Dan Dailey. Knowing that this would make it difficult for Dailey to get insured on future projects, virtually guaranteeing an end to his acting career, Cohen canceled the insurance coverage on the entire cast. In this way, the application for Dailey's insurance was torn up, and there was no record of his having been denied coverage. It also meant that Cohen and the production were vulnerable if any of the older cast members died or became incapacitated before shooting ended, but Cohen felt the risk was worth it for the sake of Dailey's career. As it turned out, Dailey broke his hip shortly after production ended and died 10 months after the film was released. This was his final film.