The real John McVicar is seen briefly at the bar wearing a green top about 11 mins before the end of the film
Due to a home office ban forbidding film crews filming UK prison exteriors/ interiors; all the prison scenes were filmed in Ireland.
Although in the book on which the film is based, McVicar was in prison with many infamous criminals of his day, the majority of characters in the film have fictitious names. For example, the character of Cody is based on the notorious Moors Murderer Ian Brady, and his girlfriend, mentioned during the riot scenes (as McVicar and others read the transcription from Cody's trial), is Myra Hindley.
When the picture was completed, Roger Daltrey said that he wanted to make a film that would show that a life of crime is a waste.
Sadly, the real life John McVicar's son, Russell Grant McVicar, decided to follow in his father's footsteps before he was reformed. The younger McVicar was jailed for the 1998 robbery of a Picasso painting in London. He is still serving time.