WILHELM SCREAM: Immediately following the bus tire being shot out a wilhelm scream can be heard.
The gun used by all the cops was the Glock 19 which is chambered in 9 mm.
Several of the phones used by characters in the movie were the Nextel Motorola i670.
Bruce Willis' character's name "Jack Mosely" is derived from Robert De Niro's character in Midnight Run (1988), where he was in a similar situation playing a bounty hunter who had to bring his subject across the country whilst being chased by the mob and the FBI. The character was called "Jack Walsh" and for most of the movie was using a stolen FBI badge and going under the name "Alonso Mosely".
Mos Def'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 in Quentin Tarantino's Reservoir Dogs (1992).
In order to make Det. 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.
The empty bottle Jack pulls from his desk drawer near the beginning is a bottle of Gosling's Black Seal Rum, from Bermuda.