In the earlier first two drafts of the script, Lorna had the same personality, but was still completely different, had a different name, and wasn't a woman, and was actually just as lethal and crazy as Riggs, which made that character his match. Riggs did, however, still had a different love interest in those drafts. He was actually having an affair with Roger's older daughter Rianne, which explains a couple of parts in the finished film, where Roger suspects that Riggs and Rianne are having an affair, those parts are only bits left from the original drafts, where the two of them were a secret couple.
It was Richard Donner
's decision to change the parts of the original scripts, which included changing Lorna into a woman, and turning her into Riggs' love interest, bringing back Leo Getz (in the original script, it was explained that Leo moved to New York City, and all of the scenes with him were written in afterwards), toning down some of the bigger action parts of the scripts, refusing to develop the villains of the script, and instead focusing more on the relationship between Riggs and Murtaugh.
Screenwriter Jeffrey Boam
didn't really like Donner's changes that he made on his script, but he also wasn't very angry about it. Boam was fired after he wrote his first two drafts of the script, since Donner wasn't interested in reading it, and because he didn't liked some parts of it. After Robert Mark Kamen
was hired to re-write the script, Boam was brought back a couple of weeks later, when filmmakers didn't like Kamen's re-writes. Boam tried to work with Kamen, but he would always end up re-writing everything that Kamen wrote, so in the end, he asked to work alone on the re-writes, and Kamen left. Much like he had to keep re-writing the script for Lethal Weapon 2
(1989), during both pre-production and filming, Boam had to keep re-writing his script for third film the entire time during a four month long production, from October 1991 till January 1992. All of the actors and actresses didn't like the constant re-writes of the script, and by the end of production, the script was re-written over forty times. Carrie Fisher
, who at the time worked as a script doctor, also worked on the script for this movie, mostly on dialogue, and she wrote most of Rene Russo
's dialogue in the final film.
In a 2012 interview for craveonline, Kamen said how he actually did a lot of work on the scripts for Lethal Weapon 2 and 3, when he was working as an uncredited screenwriter for Warner Brothers, and would often do lot of re-writes on their films, and how a lot of the stuff he added in the script for this movie, are still in the film, which is why he is credited as writer, along with Boam. Kamen didn't get a credit for his work on Lethal Weapon 2, although lot of the stuff he added during re-writes, ended up in the film, like all of the parts with the South African villains. See more
We can't shoot a dog. People? Okay, but not dogs.