Royalty, politics, scandal and an inconvenient murder

It’s an international mystery that has endured for a century. Was the murder of a policeman covered up on the orders of the Prime Minister and Home Secretary to protect the Prince of Wales?

Full story of the murder of Sgt Thomas Green during the Epsom riot of 1919 in Scotland Correspondent magazine

Full story in Scotland Correspondent magazine

It is 100 years since Police Sergeant Thomas Green was killed on 17 June 1919 by a Scots-Canadian soldier identified as the ring leader of a riot involving more than 400 angry and embittered troops in Epsom, Surrey.

Following the end of World War One many Canadian units were billeted on the outskirts of Epsom. They were among the last troops to be sent home because there were too few transport ships and Britain needed to keep soldiers on standby until Germany officially signed the Treaty of Versailles.

Full story and more images in Scotland Correspondent magazine

Bored, homesick and angry resentment among the waiting troops spilled over and, on the fateful day, a brawl broke at The Rifleman pub in Epsom between soldiers and local residents.

The police were called and a Canadian soldier was arrested, along with another trooper who tried to intervene.

At nearby Woodcote Army Camp, where more than 2,000 Canadians had been billeted, a bugle call to arms succeeded in forming a rescue party of more than 400 soldiers who marched on the town to free their comrades, smashing windows and tearing down fences on the way.

Police Inspector Charlie Pawley and a Canadian army officer tried to reason with the mob but were forced to retreat when the soldiers began hurling rocks, smashing windows and ramming the front door of the police station with a large fence post ripped up from a nearby garden.

In a pitched battle between the soldiers and the besieged police several officers were injured, including Sergeant Thomas Green, 51, who was hit over the head with an iron bar. He died the following morning from his injuries.

Police Sergeant Thomas Green murdered during a riot by Canadian soldiers at Epsom on 17 June 1919

Sgt Thomas Green 1912

Unfortunately the riot could not have happened at a more politically sensitive time. Many people in countries throughout the Commonwealth were asking why so many of their young men had been killed or wounded during the First World War.

In early 1919, Lloyd George suggested a Royal Tour of the Commonwealth countries that had answered Britain’s call to arms as a gesture of thanks. It was decided Edward, Prince of Wales, would embark on a series of visits starting in August. But the events of June 17 plunged the tour into jeopardy

“Somebody within the government must have realised that unless the situation was brought under control a large number of Canadian soldiers were going to be arrested and charged with affray. Some might even be charged with murder and hanged just as the Prince was visiting Canada. It was the worst public relations disaster possible,” said Edward Shortland, a retired Scotland Yard police detective who spent five years investigating the cold-case.

He believes the killer escaped execution for fear of jeopardising a visit to Canada by the Prince of Wales and that any cover-up must have involved the Prime Minister, David Lloyd George, the Home Secretary, Winston Churchill, and the Metropolitan Commissioner. Only they would have had the power to influence the investigation and subsequent trial.

According to Mr Shortland the police investigation into Sgt Green’s death was full of anomalies and lost opportunities from the start. There were delays in the questioning of a vital witness; there was no search for the potential murder weapon; and the main suspect was never put into an identity parade.

“They couldn’t cancel the tour and if they sent the Prince while Canadian soldiers were facing jail or even execution it might put him at risk. The only alternative was to play down the incident as a lively brawl which had unfortunately ended in tragedy,” said Mr Shortland.

Leading the investigation into the riot and death of Sgt Green was a highly experienced police officer, Inspector John Ferrier.

Allan James MacMaster who confessed to killing Police Sergeant Thomas Green during a riot by Canadian soldiers at Epsom on 17 June 1919

Allan James MacMaster

On 19 June 1919 Ferrier went to the Canadian camp and arrested anybody who appeared to have been in a fight. One of the men detained was Allan James MacMaster, 30, a private in the 3rd Canadians, who suffered a head wound in the riot. MacMaster was an imposing 6ft tall former blacksmith and suspicion immediately fell on him.

Witness testimony pointed to MacMaster being the ringleader and the killer but Insp. Ferrier did not follow up the lead until four days later, by which time the Canadians had closed ranks.

While the investigation was going on Sgt Green was laid to rest in the Ashley Road Cemetery, Epsom. Thousands of mourners lined the route, including 800 police officers and river police, 60 special constables, fire brigade members, council workers and officers from the Canadian army. Every shop on the route was closed and most of the houses had their blinds drawn.

As detailed in the book by Martin Knight, ‘We Are Not Manslaughterers’ published by Tonto Books, seven Canadian soldiers were eventually tried at Guildford Assizes for manslaughter and rioting.

Among them were James Connors, born in Montreal in 1899; Robert Alexander McAllan, born in Glasgow in 1874 but emigrated to Canada in 1907; Allan James MacMaster, born in 1889 at Lower Hillsdale, Judique North, Nova Scotia – a descendant of Scottish immigrants; David Wllington Yerex born in 1887 in Galt, Ontario; Frank Howard Wilkie born in 1897 at Guelph, Ontario; Alphonse Masse born 1892 of Montreal and Robert Todd, an ex-Barnado’s Boy from Belfast who had emigrated to Canada and joined the army as a bugler.

We are Not Manslaughterersby Martin Knight, the full story of the muddier of Sgt Thomas Green during a riot by Canadian soldiers at Epsom on 17 June 1919

Martin Knight’s book

At the end of the two day court case, just 36 days after the murder, verdicts of “not guilty” were returned on two of them, Todd and McAllan. The remainder were found “not guilty” of manslaughter but “guilty” of rioting and were sentenced to 12 months imprisonment. Less than five months later they were pardoned and sent home.

A few years later Sgt Green’s daughters went to live in Canada while the men involved in their father’s premature death tried to put the past behind them. All of them except MacMaster.

Ten years after the riot Allan James MacMaster walked into a police station in Winnipeg and confessed to the murder to ease his conscience.

The Canadian police cabled London with the message: “Am detaining Allan MacMaster, who admits being murderer of Police Sergeant Green at Epsom on June 17, 1919. Do you want him? Wire instructions.”

Scotland Yard cabled back: “MacMaster sentenced in connection with this affair and he is not wanted.”

In 1939, aged 50, Allan James MacMaster killed himself.