Anecdotes

The movie, notable for its car chase, was produced and directed by Philip D'Antoni, who had also produced Bullitt (1968) and French Connection (1971), two pictures which were also notable for their car chases.

None of the car chase was rehearsed, as the producers knew that if the police and authorities assisting the shoot, saw what was planned, they would never have given permission for it to proceed.

The vehicle that Roy Scheider is seen driving is a 1973 Pontiac Ventura Sprint coupe.

According to Dennis Farina in Episode #3.1 of "Dinner for Five" (2004), this film was the most realistic in its depiction of cops. Farina was once a cop who worked in Chicago.

This was the only film directed by Philip D'Antoni.