The story that Ethan Bishop (Austin Stoker) tells about his father sending him to a police station when he was six years old with a note is actually a true story told about his childhood by Alfred Hitchcock. Hitchcock told this to François Truffaut in Truffaut's book "Hitchcock".
The assault takes place on Precinct 9, Division 13. Many have noted the title misnomer, since there is no "Precinct 13" in the film. At first John Carpenter wanted to call the film "The Anderson Alamo" (the original title of his screenplay), and at one point he changed the working title to "The Siege." CKK, the film's distributor, was responsible for the misnomer; it rejected Carpenter's titles and came up with the name "Assault on Precinct 13" (which it felt was more ominous sounding) during post-production.
Darwin Joston's portrayal of convict Napoleon Wilson is inspired by Charles Bronson's character "Harmonica" in Once Upon a Time in the West (1968) ("Once Upon a Time in the West"); when asked to explain themselves and their actions, both respond, "Only at the point of dyin'." As Wilson explains why he has killed so many people, he recalls that when he first saw a preacher, the preacher told him, "Son, there is something strange about you. You got something to do with death." This quote belongs to Jason Robards' character Cheyenne in "Once Upon a Time in the West" and is the title of Christopher Frayling's biography of Sergio Leone.
Following the release of his first feature, Dark Star (1974), John Carpenter was approached by a group of investors who gave him carte blanche to make whatever kind of picture he wanted, albeit with a very limited budget. Although Carpenter wanted to make a Western, he knew he wouldn't have the resources to make a period piece. He wrote this film as a highly stylized, modern-day western, essentially remaking Rio Bravo (1959), which was directed by Carpenter's hero, Howard Hawks. Carpenter acknowledges this debt to Hawks and "Rio Bravo" by using the pseudonym of John T. Chance for his film editor's credit, which was the name of John Wayne's character in "Rio Bravo".
This was a bigger hit in Britain than it was in America, largely because British audiences understood and enjoyed the film's similarities to American Westerns, whereas US audiences were too familiar with the Western genre to fully appreciate the movie.
John Carpenter wrote the score in three days. He made three to five separate pieces of music and edited them in accordingly. It didn't become available to buy until 2003, through the French label Record Makers.
During the filming of the dialogue-heavy scene between Darwin Joston and Charles Cyphers on the prison bus, the bus was being driven, rather than towed. Joston couldn't hear his own voice, because the bus' loud engine was directly underneath him.
In 1983, Sydney-based rock and roll band New Christs released a single "Born Out Of Time". The song was inspired by that line in the movie, the back of the sleeve features "Dedicated to Napoleon Wilson".
Napoleon Wilson talks about riding in the bus for hours as they go to Sonoma to put him on Death Row. Obviously he is going to San Quentin State Prison located in Marin County, which borders Sonoma County.
The trivia items below may give away important plot points.
The MPAA threatened an "X" rating if the shocking "ice cream scene" wasn't cut. The distributor advised John Carpenter to give the MPAA a version with the scene excised to get an "R" rating, and then simply distribute the original version complete with the scene. The ruse worked.
The film received a wave of unexpected, unsolicited publicity in the late 1990's due to an interview with Mel Gibson where he described how he liked movies that "went too far" and then described the "ice cream scene" in this movie in detail, adding he was sitting stunned in an Australian theatre watching a little girl get shot in the chest and die a bloody death. Fans of Gibson who mostly had not heard of the film began seeking it out and the good word-of-mouth turned into a major success on the video rental market.