Acting in the Dark: During the scene when Jake plays cards with the Latino gangsters, Antoine Fuqua gave certain lines of dialogue to the actors playing the gangsters, without telling Ethan Hawke. This was done to further confuse him and add to the tension of the scene.
Actor-Inspired Element: To give to his character a much more authentic aspect, Denzel Washington decided to have the same look as disgraced L.A.P.D. Officer Rafael Perez.
Award Category Fraud: Ethan Hawke was nominated for Best Supporting Actor at the Oscars, despite playing the film's protagonist. This was presumably to avoid competition with Denzel Washington, who ultimately won Best Actor.
Cast the Expert: Cle Sloan, the gang Technical Advisor of this movie, managed to get on-screen real-life gang members from Rollin' 60 Crips, P.J. Watts Crips, and B.P. Stones Bloods.
A scene was filmed that reveals Alonzo wasn't always corrupt. Alonzo and Jake drive to a house belonging to a man called Spooky. Alonzo tells Jake that during his second week on patrol as an LAPD cop he pulled up outside Spooky's house and he witnessed an old man called Tufine beating a dog with a garden hose. Alonzo wanted to get out of the car and do something about it, but his partner wouldn't let him because Spooky paid Tufine to beat the dog to teach it to hate colored people. Alonzo adds that he'd almost quit and taken a bus back home right then and there.
Just before Jake gets on the bus and goes back to The Jungle to confront Alonzo, Smiley reveals that Alonzo wanted him to kill him by setting him on fire in front of his wife and child.
Fake Nationality: Smiley, a Latino gangster, is played by Cliff Curtis, a New Zealand actor of Maori descent.
Playing Against Type: Denzel Washington as the unrepentantly evil Alonzo Harris is one of the first examples of this trope many film buffs think of when asked.
Saved from Development Hell: David Ayer wrote the first draft in 1995, way before the Rampart Scandal made headlines in 1998. In the first draft, Alonzo was a Latino officer in charge of drug enforcement in the gang infested area of Pico-Union within the Rampart Division. He was a loner and didn't have any partner because of his reputation as a corrupt and racist cop. But the basics elements of the character were there: he wears expensive jewelry and drives a 1979 Monte Carlo.
That was an in the moment thing. His ego was so big that King Kong didn’t even register. I always tell people that in the end of Training Day, when he gets out of his car, he’s heading to his trunk to try and get some guns. He still thinks that he can get away with it. He was all about the ego.
Washington also improvised Alonzo scraping his two guns together as if he were sharpening knives.
Before Antoine Fuqua was involved in the project, Davis Guggenheim was set to direct with Samuel L. Jackson as Detective-Sergeant Alonzo Harris and Matt Damon as rookie Officer Jake Hoyt. When Denzel Washington accepted the role as Detective-Sergeant Alonzo Harris, Guggenheim was replaced per his request.
Tobey Maguire was seriously considered for the part of Officer Jake Hoyt. He even followed Undercover Narcotics officers in Los Angeles for two months and gained weight for the role. He was dropped when Ethan Hawke, Fuqua's first choice, was finally available for the shooting schedule. Eminem was offered the role, but he was busy with 8 Mile. Had he accepted the role, he would've shared scenes with Snoop Dogg and his mentor Dr. Dre. Christian Bale, Ryan Phillippe, Freddie Prinze Jr., Scott Speedman, Paul Walker and Mark Wahlberg were also considered.
Antoine Fuqua wanted Mickey Rourke to play Roger, but the studio turned him down.
The original ending of the script was Hoyt crashing the pad of Alonzo's girlfriend and find his training officer in the middle of an orgy with two young women. Hoyt shows him the money that Smiley was supposed to deliver to the Russians and tells him that there is a crew of hit men looking all over for him. Alonzo then commits suicide in front of Hoyt.
TV Series:
Died During Production: Bill Paxton passed away on February 2017 due to complications from surgery. CBS cancelled the series three months later (though due to its already-flagging ratings, Paxton's death was likely just the final nail in the show's coffin).
