The character of Jupp (Denholm Elliott) was based on disgraced Flying Squad commander Kenneth Drury.

John Thaw once said of this movie for its publicity: "The Sweeney really is your urban western. But the team, the cameramen and the director, are almost semi-documentary in style, and therefore you get much more sense of reality than you would in a studio set-up. And we never work in a studio."

The movie was filmed during November and December 1977.

This movie launched in cinemas in mid 1978 around eighteen months after Sweeney! (1977) debuted.

The term "blagger" is frequently heard in the movie, it is a slang colloquial expression for "bank robber".

Neither this movie nor Sweeney! (1977) had a title that conformed with its source television series title, The Sweeney (1974), dropping the word "The" in both cases. It would not be until The Sweeney (2012) was made, that this would occur.

The name of the police unit was "The Flying Squad". This is in real life an actual police division. Wikipedia explain it as being "a branch of the Specialist Crime & Operations section, within London's Metropolitan Police Service. The Squad's purpose is to investigate commercial armed robberies, along with the prevention and investigation of other serious armed crime. Possibly one of the best known operations of the squad was their foiling of the Millennium Dome raid".

Dennis Waterman once commented on the violence in The Sweeney (1974) while doing publicity for this movie by saying: "It's certainly no more violent than the real Flying Squad. The stories that we hear from policemen that we know are terrifying. We don't introduce gratuitous violence, but it is, in real-life, a violent job, and to pretend otherwise would be ridiculous."

In the Season 4 episode Hard Men, which was made the same year as this movie, 1978, James Warrior, who plays the quirky detective Jellyneck, was directed to do certain things to distinguish his character, including picking his nose, which he does in several scenes in this movie as well, including one that also opens the trailer: when the men are looking at women crossing the street during a stakeout.

There was a big buzz excitement for the cast and crew about travelling to an exotic locale like Malta for some of the filming.

Director Tom Clegg did not direct Sweeney! (1977), but had directed many of the episodes of The Sweeney (1974).

The movie's signature weapon was a gold-plated Purdey (James Purdey & Sons) sawed-off shotgun. This movie was released four years after The Man with the Golden Gun (1974).

The movie's signature stunt, the driving of a car through a shop-front window, or a "death defying car leap" as the publicity exclaimed, was filmed in one take with three cameras. The window was on a mezzanine floor, about ten feet (three metres) above the ground.

This movie and Sweeney! (1977), spin-offs from the source television cop series The Sweeney (1974), were released while the series was still being broadcast.

The production shoot for this movie ran for five weeks.

Shooting in Malta, John Thaw returned there for the filming of the Sherlock Holmes television movie The Sign of Four (1987).

During the film's prologue involving Denholm Elliott as a crooked police chief, Regan tells a lawyer that his boss is so crooked, he can hardly straighten the pictures on his office wall. This sounds like one of Regan's many quips. But in the next flashback scene, we learn he's speaking literally as a picture of Elliott's Jupp and Regan is crooked on the wall near the door.

It's likely this film takes place over three years after the television series ended since, like the first theatrical film, Sweeney!, Haskins is not in charge of The Flying Squad. Instead, for the last three years, Denholm Elliott's character had been in charge, and he'd been doing Haskins' job as Chief, and was not in the first feature.

Bearded and overweight actors James Warrior, as Jellyneck, and Barry Stanton, as Big John, both playing Flying Squad detectives, look very similar except that Jellyneck is short and Big John is tall. And while we see Jellyneck's short stature throughout the movie, we only see Big John one time, sitting inside a vehicle. After which, off-screen, he's injured and has his foot removed: leaving only Jellyneck in the movie. So make note that the overweight bearded guy throughout the entire movie is James Warrior as Jellyneck. Meanwhile, cameo Barry Stanton is billed five actors before James Warrior.

Throughout the entire series and in the first theatrical film, Bill the Driver, played by Tony Allen, is Regan's faithful driver. In this movie, he makes a brief cameo, driving Regan away from the courthouse. Since an entire subplot involves Regan's newest driver, Big John, losing his foot (in the very beginning) in a crash, and then Regan clashing with sophisticated vegetarian driver replacement, Bill isn't used much here.

This was the last time we'd ever see these characters; particularly Jack Regan (John Thaw) and George Carter (Dennis Waterman), who, in the series and the films, are basically womanizers, and successful at that. But the last women they wind up with, despite the character names only naming their jobs (Telephone Operator and School Teacher), are both sarcastic, quick-witted, and neither give in quickly to Regan or Carter's charms, keeping them off-guard (in Regan's case, until the very, very end). So perhaps these "birds" (as woman are called in this movie and the show) will remain significant others in the unknown and unseen future.

Final "Sweeney" movie in what became a 1970s British two movie franchise until The Sweeney (2012).

Final "Sweeney" movie until The Sweeney (2012).

In the credits and throughout the movie Ken Hutchison's character, the lead bank robber, has the name of Hill (his wife, Mrs. Hill). But in one scene his first name is quickly mentioned as Frank.

Much of the movie was cast by Director Tom Clegg.

Sir Nigel Hawthorne played Dilke, a police superior character, who was the equivalent of the police superior character that had been played by Garfield Morgan in the television series, The Sweeney (1974). Morgan was absent from both Sweeney feature films due to theatrical commitments.

Several scenes from this film are used in the video for The Flying Lizards 1979 single, "Money-That's what I Want" (a cover of The Beatles original).

The name of the Mediterranean island to which the detectives travelled was Malta.