The gun shop used in the film was a real shop based in Park Street, St. Albans in Hertfordshire and is still going strong today.
On the board on the front of the gun shop, the telephone number has had the area code changed from 0727, St. Albans, Hertfordshire to 0273, Brighton, East Sussex where the film is set.
There was some mild controversy over this film after it's UK video release after the press started attacking violent content in films after the 1993 Jamie Bolger murder outrage and the supposed link to the killers enjoying watching violent films. At this point the UK press turned on any film with violent content. This was one of the handful of films that was vilified by the press.
The white BMW, registration number G716 SKX, that can be seen parked outside David's house, is the same BMW driven by Mr Brown later in the film.