In Internal Affairs (1990), Richard Gere's character Dennis Peck says to his partner Van Stretch, "How many cops you know, huh? Got nothing. Divorced, alcoholic, kids won't talk to them anymore, can't get it up. Sitting there in their little apartments, alone in the dark, playing lollipop with a service revolver?". In this film Richard Gere plays an NYPD cop who is doing just that in an opening scene: sitting alone in a dark apartment and putting his service revolver in his mouth.
Wesley Snipes' first US theatrical film in over five years since his starring role in Blade: Trinity (2004). In between those years, his films had either been released straight-to-DVD or suffered distribution problems (Chaos (2005)) before being released to DVD.
When Tango and Lt. Bill Hobarts meet for the first time in the restaurant, the song "The Great Pretender" by the Platters (1955) can be heard in the background. That can be seen as a reference to Tango's job as an undercover cop.
In the scene where Duggan (Gere) is getting dressed towards the beginning of the film, he has a conversation with two hostile fellow officers. One of the officer's duty shirt is unbuttoned and his Kevlar vest can be seen. The vest, however, is way too low on his abdomen and would not cover his heart and lungs. Any patrol officer would know better than to wear his vest like this, and the straps would have to be adjusted significantly for the vest to be worn properly.
The trivia items below may give away important plot points.
Towards the climax of the film, all the key Police characters in the film are in one long scene, shot with no cuts. As 'Sal' arrives to the project tower block to see the informants, he waits to cross the road as the van with the missing woman being pimped out passes him, followed by 'Eddie' tailing the van in his car. At the other side of the road, we see 'Tango' getting out of his car. All the characters are oblivious to each other however.
The original ending as shown in Sundance had Eddie (Richard Gere) committing suicide after his retirement following the climax, which serves as to bookmark the ending from the opening. Director Antoine Fuqua eventually decided to end the film instead with a freeze frame of Eddie's face with blood and eyes swollen because he pointed out that the face, in metaphor represents America, dazed and confused, but still moving forward. He added, "There's still some hope, we still have a chance. We've taken some hits, but we're still standing. It kind of came out of everything that was happening."