The funeral scene footage was actual footage from the funeral of NYPD police officer Eric Hernandez, who was killed in the line of duty.
Nick Nolte was originally cast as Francis Tierney, Sr., but an old knee injury flared up and Nolte found himself unable to perform when he came to the set. Nolte later revealed in his memoir that he quit the film because he couldn't stand Edward Norton's "cocky" attitude.
In 2001, Mark Wahlberg and Hugh Jackman were in talks to star. Production was scheduled to begin in February 2002. After the September 11, 2001 attack on New York City and the celebrated heroics of the city's police, however, it was deemed inappropriate to make a film featuring corrupt NYPD officers at the time.
The film was made back in 2006 and left on the shelf at New Line Cinema, destined not to see the light of day until Warner Brothers picked up New Line Cinema's content.