The investigation is a 1963–64 detective case: a farm, prints and a national manhunt.
Steps below are what police did after the bags left the train, not how the train was stopped.
Agencies
- Buckinghamshire Constabulary — First force on the bridge and the force that found Leatherslade Farm.
- Scotland Yard Flying Squad — Lead London detectives on the gang, later famous for hunting Biggs.
- General Post Office / Royal Mail — Victim organisation; counted bags and notes and changed later TPO practice.
- Aylesbury Crown Court — 1964 trial court under Mr Justice Edmund Davies.
What followed
- Secure the line
Officers treated Bridego Bridge and the train as a crime scene and took first accounts from Mills and Whitby.
- Find the farm
Local inquiry and search located Leatherslade, converting a rural hideout into a forensic scene.
- Match prints and vehicles
Fingerprints and stolen-vehicle trails produced names. Arrests followed through late 1963 and 1964.
- Try the gang at Aylesbury
The 1964 trial produced the thirty-year terms that defined the legal afterlife.
- Hunt the absconders
Wilson's recapture in Canada and the long Biggs pursuit were extradition and celebrity-police stories on top of a finished conviction.
- Catch Reynolds
The 1968 arrest of the planner closed the leadership file the first sweep had missed.
Turning points
- Leatherslade discovered — The farm turned a successful night into a prosecutable one.
- The thirty-year tariff — Edmund Davies's sentences told the public this was not to be romanticised as a prank.
- Biggs in Brazil — The escape did not unpick the verdict; it created a second, tabloid case that lasted until 2001.
After the fact, two police forces and a stern judge closed the who question. The notes were another matter.
Public-record encyclopedia. Not legal advice. Not a how-to. Graphic detail is withheld. Wars belong in a separate atlas.