- Breakthrough Hit: For Shane Black.
- Career Resurrection: Gary Busey credits the film for saving his career.
- Dawson Casting: Rianne was supposed to be around 17-19, played by then 25-year old Traci Wolfe.
- Deleted Scene: Riggs originally had a different introduction. In it, Riggs is sitting alone in a bar getting drunk. He finishes off one bottle of Jack Daniels and orders another, but the bartender, both concerned for and wary of Riggs, cuts him off. Riggs stumbles into the back and is accosted by two hoodlums. He tries to warn them off, but they don't listen. He ends up crippling them and the bartender is not surprised. He tells Riggs as a friend to get out. Richard Donner felt it was too dark to open the film with. He felt that with the show of violence, viewers would judge Riggs' character before they got the chance to know him. Hence, he changed Riggs' introduction to the lighter, funnier morning scene in his trailer.
- The Blu-Ray release contains deleted scenes not in the Director's Cut. Murthaugh's family scene was longer, with him interacting with Carrie and chastising Rianne for spending money on shoes; the jumper scene is longer; the fight in the pool is longer; Josuha surprises Rianne and her boyfriend before kidnapping her (which happens offscreen); and Riggs reassuring Carrie they'll rescue Rianne.
- Dyeing for Your Art: Gary Busey dyed his hair blonde to play Mr. Joshua.
- Enforced Method Acting: In the scene where Riggs is contemplating suicide, there is an actual bullet in the chamber which Mel Gibson was pointing at his head, thinking that it would allow for a greater sense of portraying the scene realistically and dramatically—and foolishly.
- In Memoriam: The film was dedicated to legendary stuntman Dar Robinson, who was killed in a motorcycle accident shortly after principal photography was finished.
- Inspiration for the Work: Shane Black was inspired by Dirty Harry to create an "urban western" where a violent character "reviled for what he did, what he is capable of, the things he believed in" is eventually recruited for being the one that could solve the problem.
- Missing Trailer Scene: Theatrical and TV trailers for the film show few deleted and extended scenes that were never released in full on any DVD or Blu-Ray release of the movie; Murtaugh saying "New Partner?" after he gets thrown to the floor by Riggs when they first meet and when he is told that Riggs is his new partner, Riggs and Murtaugh driving in the car and Murtaugh telling Riggs "Don't kill anybody" and Riggs repeats the same line, couple shots of short deleted scene where Murtaugh is shooting his gun at target range alone, Riggs beating up two guys who try to rob and kill him while he is in the bar (original introduction scene for his character), and Riggs saying additional line "Nobody can touch me" after Murtaugh asks him is he really that good as he says he is.
- Name's the Same: The Big Bad of this film is Peter McAllister, not Peter McCallister.
- No Stunt Double: Jackie Swanson did perform the high fall on her own. Trained by legendary stuntman Dar Robinson. Also, the stunt was done using an airbag covered with a life-size painting of the driveway and cars, which, like a foreground miniature, visually blends into the real scene. Thus, the editor is able to hold the shot until just as she makes contact with the airbag, for greater realism.
- Star-Making Role:
- Whilst Mel Gibson had commercial success in the Mad Max films and critical success in Gallipoli and The Year of Living Dangerously, the original Lethal Weapon was the film that established him as an A-lister.
- Danny Glover was primarily a character actor in supporting roles before the original film proved that he was a capable leading man.
- Underage Casting: Danny Glover was only 40 years old when he was playing 50 year old Murtaugh. Even more amusing is that the actress who's playing his younger wife, Darlene Love, was actually five years older than Glover in real life.
- Riggs is supposed to be in his late thirties to early forties, but Mel Gibson was only 30 at the time of filming.
- Unintentional Period Piece: The film establishes that Murtagh and Riggs are both Vietnam War veterans, as are the villains.
- What Could Have Been:
- According to a 2016 interview with Joel Silver, Ridley Scott was his first choice to direct the film. Due to Scott's still recent tensions with Warner Brothers, during the making of Blade Runner, the studio refused to offer him the job.
- Leonard Nimoy was one of the choices considered for directing, but he didn't feel comfortable doing action movies, and he was working on Three Men and a Baby at the time.
- Shane Black wanted William Hurt for Martin Riggs, but studio executives informed him that Hurt was too obscure for the part. Alec Baldwin, James Belushi, Michael Biehnnote , Jeff Bridges, Pierce Brosnan, Nicolas Cage, Kevin Costner, Willem Dafoe, Robert de Niro, Michael Douglas, Harrison Ford, Richard Gere, Jeff Goldblum, Rutger Hauer, Don Johnson, Michael Keaton, Kevin Kline, Christopher Lambert, Michael Madsen, Liam Neeson, Al Pacino, Sean Penn, Dennis Quaid, Christopher Reeve, Eric Roberts, Kurt Russell, Arnold Schwarzenegger, Tom Selleck, Charlie Sheen, Sylvester Stallone, Patrick Swayze, John Travolta and Bruce Willis were also considered.
- Stephen Lang and Ron Perlman was considered for Riggs and Mr. Joshua.
- Peter Boyle, Bruce Dern, Robert Duvall, James Earl Jones and Lee Marvin were considered for General McAllister.
- Keith Carradine, Scott Glenn, Tommy Lee Jones, John Saxon, Christopher Walken and James Woods were considered for Mr. Joshua.
- Shane Black's original draft was much darker and more violent. The sniper scene in the Director's Cut one dead kid being carried on a gurney and the draft ended with a big chase scene including a police helicopter which gets blown up by Joshua who fires napalm missile at it causing it to crash into the Hollywood sign and start a huge fire, Murtaugh killing General McAllister while he is driving a a trailer truck full of heroin and guns which then crashes and explodes over Hollywood Hills causing for heroin to start snowing over the burning Hollywood sign, and Riggs killing Joshua by stabbing his finger through Joshua's eye right to the brain.
- Riggs was a much different character in the first draft than he is in the movie, and lot more mentally unstable. For example, in the original version of the scene where he kills a sniper who is shooting at the kids, instead of using his gun Riggs uses a rocket launcher to blow up the sniper after he shot and killed several kids. In another part of the script he also uses ninja throwing stars to wound one of the villains and then tortures him for information. He and Murtaugh both had flashbacks of their time in Vietnam, with Murtaugh at one point remembering how he accidentally killed a young soldier with his bare hands during intense military training even before he went to war, and Riggs remembering how great killing machine he was and how much people he killed working as an assassin for CIA, which is why US and VC soldiers considered him a legend.
Trivia / Lethal Weapon (1987)