In order to make Detective Jack Mosley's limp look realistic on screen, Bruce Willis put a pebble in his shoe and kept it there throughout the length of the shoot.
Yasiin Bey's character has the name "Edward Bunker". Edward Bunker is a real-life criminal turned actor (thus proving that people can change, in line with the theme of the movie), who appeared as Mr. Blue in Quentin Tarantino's रेज़र्वायर डॉग्स (1992) and as Jonah in Runaway Train (1985) which he also co-wrote. When he was sent to prison, Bunker was the youngest man there.
Eddie Bunker, played by Yasiin Bey, cites Chuck Berry as an example of a man who was able to change his life after getting out of prison. Two years later, Yasiin Bey played the part of Chuck Berry in the movie Cadillac Records (2008).
Yasiin Bey appears credited in this movie by his then artistic name, Mos Def. He changed it to Yasiin Bey in 2011.