Detective Chief Superintendent Tommy Butler was a key player in solving the Great Train Robbery which took place at 3am on the 8th of August 1963 in Buckinghamshire, England.

The daring heist, which involved the meticulous planning and coordination of a two gangs that totalled around 17 criminals, hadn’t banked on the diligent detective work of Tommy “One Day” Butler.

He didn’t crack the case alone.

Among the key players were the involvement of the public and railway employees, who provided vital information regarding the train’s schedule and security measures, played a significant role in piecing together the evidence.

The Buckinghamshire Police and Scotland Yard Detectives, who employed innovative investigative techniques of the time, utilizing witness statements, forensic evidence, and extensive surveillance operations to track down the gang responsible.

Additionally, the media coverage surrounding the robbery also added pressure on the police to resolve the case swiftly, highlighting the public’s demand for justice and accountability, which ultimately led to several arrests and convictions in the years that followed.

For the last month or so, our Talk Dialect Detectives have been helping hunt out Buckinghamshire dialect words and phrases. Unsurprisingly, we have stumbled into and discovered many many police and crime dialect words too.

Here are the some of the key people and keywords from The Great Train Robbery, the crime of the 20th century in Great Britain 🇬🇧🕵️‍♂️

🌾 THE TIP-OFFS & CIVILIAN LEADS

The local herdsman — the single most important civilian tip. Following a tip-off from a herdsman who used a field adjacent to Leatherslade Farm, a police sergeant and constable visited the property five days after the robbery. The herdsman told police there had been unusual activity and various vehicles he hadn’t seen before. The farm was deserted but the vehicles and mountain of forensic evidence remained.

His name was John Maris. The police and the Investigation Branch received many tip-offs in the following days, one of which was from a farm worker in Leatherslade named John Maris. Mr Maris first became suspicious of the neighbouring property when he heard that the new occupants had offered a hundred pounds over the asking price, they also did not seem to do any work, and particularly suspiciously had blacked out all the windows. After the robbery, several vehicles appeared in the yard.

John Maris explained at the time: “My suspicions were aroused by the fact that all the windows were blacked out, and a motor lorry standing in an outbuilding was covered by a tarpaulin, with only the yellow bonnet showing.”

Perhaps, somewhat embarrassingly for the police, it was reported that the police had delayed acting on the tip and had missed the robbers by just 8 hours. The police stated it was “one of hundreds and hundreds” of tips and that “all had to be dealt with”.

🤫 THE GRASSES & INFORMANTS

The Informants — Who Were They?

The Lawyer in the West End Club

The breakthrough came when DCS Millen met a distinguished barrister in the smoking room of an exclusive West End club, who told him that someone was willing to inform on the gang.

Crucially, the process of talking to the informant was handled exclusively by Hatherill and Millen — and they never divulged the identity of the informant to any of the detectives under their command. The barrister’s name has never been made public.

The unnamed jailbird informant — perhaps the most critical human source. The informant was behind bars at the time of the robbery and had associations with several of the men involved.

He didn’t know all the names perfectly, but a second female informant was able to fill in the gaps.

The names matched up with prints taken from the farm — but photos of the suspects were then published against the wishes of the Flying Squad, and the robbers subsequently went to ground.

🚔 THE POLICE

Malcolm Fewtrell — the first senior officer on the scene. Chief Superintendent Fewtrell, head of Buckinghamshire CID, arrived at the abandoned postal carriages at 5am and supervised evidence-gathering. After interviewing witnesses, he deduced that about 15 hooded men in blue boiler suits were involved, and crucially, that the gang’s hideout couldn’t be more than 35 miles away — because one robber had foolishly told staff not to move for 30 minutes. By lunchtime the next day he realised he needed Scotland Yard’s help.

Local Constable John Woolley — responding to reports of suspicious activity, he entered the recently vacated property and observed signs of hasty departure, including food remnants, clothing, and vehicles consistent with the robbery’s aftermath.

Tommy “One-Day” Butler — the main man. On 12 August 1963, the Home Secretary appointed DCS Tommy Butler, head of the Metropolitan Police Flying Squad, to lead the investigation. He immediately formed a compact six-man Train Robbery Squad handpicked from the Flying Squad. Butler was renowned for how quickly he caught criminals — hence his nickname “One-Day Tommy.” He was famously secretive — Jack Slipper later wrote that “he wouldn’t even tell his own left hand what the right one was doing,” meaning squad members were often dispatched on errands with no knowledge of how they fitted into the wider investigation.

Jack Slipper (“Slipper of the Yard”) — a tall man with a pencil moustache who became a household name for his work on the case and his long cat-and-mouse pursuit of Ronnie Biggs. Slipper became famous for his dogged attempts to bring the gang to justice, even chasing Biggs to Brazil.

DI Frank Williams — a quiet but vital member of the Train Robbery Squad, whose speciality was handling informants. He had the best working knowledge of the South London criminal fraternity of anyone in the force.

Ernest “Ernie” Millen — the detective who made the crucial informant connection. The breakthrough came when DCS Millen met a well-known lawyer in the smoking room of an exclusive West End club, who told him that someone was willing to inform on the group.

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The Biggest Mystery? — “The Ulsterman”

The “Ulsterman” was the inside man who fed the gang their intelligence in the first place. The plan was based on information from an unnamed senior security officer within the Royal Mail who had detailed knowledge of the amounts of money carried. His real identity was never officially established – Wikipedia

Gordon Goody, living in Spain in his 80s, said he first heard of the robbery plan through crooked solicitor’s clerk Brian Field. He met “the Ulsterman” — a slightly balding middle-aged man with a Northern Irish accent — at Finsbury Park, giving information in stages across multiple meetings.

Most sources now suggest a Salford postal worker called Patrick McKenna provided the original information that piqued the interest of Buster Edwards and Gordon Goody — though McKenna wasn’t identified as the inside man until 2014.

🔬 THE PHYSICAL EVIDENCE

Much of the case was also cracked by the gang’s own carelessness:

• A thorough examination of Leatherslade Farm found fingerprints on the Monopoly board and a ketchup bottle. These, combined with other enquiries, led to the offenders being identified one by one.
• Six thieves were hired to burn down the farmhouse but did such a poor job that police found everyone’s fingerprints. With this and other evidence, 12 of the 15 robbers were caught and convicted.
• Police recovered over 200 items of direct evidentiary value, forensically linking at least eight suspects.

In short, it was a combination of smart detective work by seasoned investigators like Butler and Fewtrell, who meticulously pieced together the evidence, brilliant informant handling by Williams and Millen, who knew how to extract crucial information from reluctant sources, a lucky tip from a diligent herdsman whose curiosity proved invaluable, and the gang’s own sloppiness that ultimately unravelled one of the most audacious crimes in British history.

This intricate web of factors not only highlights the dedication of law enforcement but also showcases how even the smallest detail can turn the tide in a high-stakes investigation.

The team synergy of the great British public and police work led to the cracking of a case that had captured the public’s imagination for many obvious reasons.

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What 63 Years Has Taught Us About Crime & Detection

🧠 Why Crimes Are Committed

Rational Choice Theory — Criminals weigh up risk vs reward. The Train Robbers calculated the odds carefully — inside intelligence, a remote location, military precision. Modern criminology confirms most serious crimes are planned, not impulsive. The gang’s downfall proves the theory too: small irrational choices (keeping the Monopoly board, not burning the farm) undid months of rational planning.

Opportunity + Motive + Means — The classic triangle still holds. The Ulsterman provided the opportunity (inside knowledge), greed provided the motive, and Reynolds assembled the means (the gang). Remove any one leg and the crime doesn’t happen. Modern crime prevention focuses almost entirely on removing opportunity.

Social Networks & Criminal Capital — We now understand that serious crime is almost never solo. It runs through trusted social networks built over years. Reynolds knew who to call because of shared criminal history. Modern organised crime research shows these networks are remarkably stable and operate like businesses.

Strain Theory — Post-war Britain in 1963 had enormous inequality. Many of the gang were working-class men who saw wealth all around them but had no legitimate route to it. Criminologists like Robert Merton argued decades ago that when society holds up wealth as the goal but blocks legitimate paths to it, crime fills the gap.

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🔍 How Crimes Are Solved

Forensics changed everything — In 1963, a ketchup bottle and a Monopoly board were enough. Today, a single skin cell, a hair, or a partial DNA profile can close a case. The Train Robbery was actually a turning point — it demonstrated the value of forensic examination of everyday objects, not just weapons or documents.

Informants remain the single biggest factor — Despite 63 years of technological advances, the majority of serious crimes are still solved the same way this one was: someone talks. CHIS (Covert Human Intelligence Sources) legislation in the UK now formally governs how informants are handled, protecting both them and the integrity of prosecutions. The Train Robbery showed both the power of informants and the danger of mishandling them — publishing the suspects’ photos against Butler’s wishes let most of the gang flee.

The 80/20 Rule of Criminals — Modern research consistently shows that a small number of prolific offenders commit the vast majority of serious crimes. Butler knew this instinctively — he went straight to the known South London criminal fraternity. Today, police use Organised Crime Group mapping and repeat offender databases to do the same thing systematically.

Criminals always make mistakes — This is perhaps the most consistent finding across 63 years. No matter how meticulous the planning, human error creeps in. The gang were told to burn the farm. They didn’t. One man told the postal workers not to move for 30 minutes — accidentally telling police their radius. Modern behavioural science calls this “leakage” — stress and haste cause people to act against their own interests.

Digital footprints are now unavoidable — The Train Robbers’ biggest problem was physical evidence and informants. Today, every phone call, bank transaction, ANPR camera sighting, and social media post leaves a trace. The modern equivalent of the Monopoly board fingerprints is metadata — and it’s everywhere. Very few serious criminals successfully operate without leaving a digital trail.

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🤐 The Informant Problem — Then & Now

The Train Robbery showed something that still defines policing today: the tension between using informants and the rule of law. Hatherill and Millen kept the informant completely secret — even from their own team. This got results but created accountability problems. The 2000 Regulation of Investigatory Powers Act (RIPA) and later legislation tried to fix this by regulating exactly how informants are recruited, handled, and rewarded. Yet informant-based policing remains controversial — the same system that solves crimes can be abused to protect criminals who are “useful.”

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🏃 Why Some Criminals Are Never Caught

The Ulsterman — the most important person in the entire conspiracy — was never identified in his lifetime. This mirrors what criminology now tells us: the people who plan crimes but don’t physically commit them are the hardest to prosecute. Physical presence leaves evidence. Intellectual involvement rarely does. Modern conspiracy law tries to address this, but it remains one of the justice system’s persistent weaknesses.

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🔄 The Bigger Picture

Perhaps the most humbling lesson of 63 years is that the fundamentals haven’t changed much. Crimes are still committed for the same reasons — greed, inequality, opportunity, social bonds. And they’re still mostly solved the same way — someone talks, someone makes a mistake, or a small overlooked detail gives the game away. Technology has made both committing and solving crime more sophisticated, but the human element — vanity, loyalty, fear, greed — remains the decisive factor almost every time.

The Train Robbery is really a masterclass in all of it, which is exactly why it’s still talked about 63 years on.

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Here are the some of the keywords from the crime of the 20th century in Great Britain 🇬🇧🕵️‍♂️:

• £2.6M pounds in cash – a fortune then and a fortune now.
• Barrister (unnamed) — Distinguished West End lawyer who secretly brokered the deal between Millen and the prison informant.
• Biggs, Ronnie “Biggsy” – Ronnie Biggs was a participant and organiser in the Great Train Robbery, but he became famous not for planning the crime, but for his spectacular prison escape and years as a fugitive
• Butler, Tommy (“One-Day”) — DCS, Flying Squad. Led the Train Robbery Squad. Nicknamed for how fast he caught criminals.
• Female Informant (unnamed) — Secondary grass who filled gaps in the male informant’s knowledge, giving police 18 names total.
• Fewtrell, Malcolm — Buckinghamshire CID chief. First senior detective on scene; deduced the 30-mile hideout radius.
• Brian Field — Solicitor’s clerk and inside man who connected the Ulsterman to the gang. Never fully convicted.
• Hatherill, George — Scotland Yard Commander. Jointly handled the secret informant with Millen; compiled an almost perfect suspect list.
• Jailbird Informant (unnamed) — Already in prison when he grassed — named most of the gang in exchange for a lighter sentence. Identity kept secret to this day.
• Ketchup Bottle — Overlooked item at Leatherslade Farm. Fingerprints lifted from it helped convict gang members.
• Leatherslade Farm — Gang’s hideout near Oakley, Buckinghamshire. Never burned down as planned. Goldmine of forensic evidence.
• Maris, John — Local farm worker whose tip-off led police to Leatherslade Farm. Police missed the gang by just 8 hours.
• McKenna, Patrick — Salford postal worker, now widely believed to be the Ulsterman. Never identified until 2014; never prosecuted.
• Millen, Ernest (“Ernie”) — DCS and original Flying Squad head. Met the mystery barrister; kept the informant’s identity secret even from Butler.
• Monopoly Board — Left at the farm after the gang played with real stolen money. Fingerprints on it were key prosecution evidence.
• Royal Mail Night Train – driven by Jack Mills and David Whitby.
• Reynolds, Bruce – The mastermind of The Great Train Robbery
• Slipper, Jack (“Slipper of the Yard”) — Detective Sergeant on the case; famous for his decades-long pursuit of Ronnie Biggs to Brazil.
• “The Ulsterman” — Royal Mail insider who gave the gang their intelligence. Northern Irish accent. True identity debated for 50+ years.
• Williams, Frank — DI on the Train Robbery Squad; the squad’s informant-handling specialist with deep knowledge of South London’s criminal world.
• Woolley, John — Local constable; first officer to enter Leatherslade Farm after Maris’s tip-off.