Historic police footage captured in Chesterfield will be screened to a global audience at an international film festival.
The video, shot in 1935 from a shop window, shows the activities of a group of street betters in the market place and is the earliest known police surveillance film to be used as evidence in a criminal prosecution.
According to the British Film Industry, the footage was played in the trial of 39 defendants at Chesterfield Police Court in May, 1935.
At the time, press reports said the court building had to be transformed into a temporary 'cinema' to screen the video.
The short film, Evidence, will be shown at Doclisboa Film Festival in Lisbon in October after Derbyshire Police and Crime Commissioner Hardyal Dhindsa agreed to a temporary copyright license for the organisers.
Mr Dhindsa said: "I am very proud of Derbyshire Constabulary's role in legal history and feel privileged and feel privileged to be able to share this historic footage with an international audience.
"Policing has come a long way since those early days and film evidence today including CCTV and body-worn video is routinely used as prosecution evidence in our courts.
"Advances in technology continue to push the boundaries of police investigation and capability and it's humbling to think Derbyshire played such a critical role in this evolution."
Captured by PC Saunders, the footage - which was unearthed at the College of Policing in Bramshill - also shows a troop of circus elephants.
To view the film, visit player.bfi.org.uk/free/film/watch-evidence-1935-online