He was born Oskar Josef Leschziner in Oppeln, Upper Silesia, Germany to a Jewish family. Around 1893, possibly to evade military service, he moved to London, where he purportedly worked as a bookmaker using various names, including Anderson, before settling on Slater for official purposes. He was prosecuted for alleged malicious wounding in 1896 and assault in 1897 but was acquitted in both cases. In 1899, Slater moved to Edinburgh and by 1901 was living in Glasgow. He was known to be a well-dressed dandy, who billed himself variously as a dentist and a dealer in precious stones, but was believed to earn his living as a gambler.
In December 1908, Marion Gilchrist, a spinster aged 83 years, was beaten to death in a robbery at West Princes Street, Glasgow, after her maid, Helen Lambie, had popped out for ten minutes. Although she had jewellery worth £3,000 hidden in her wardrobe, the robber, who was disturbed by a neighbour, had rifled through Mrs. Gilchrist's personal papers and taken only a brooch. Slater left for New York five days after the murder and came under suspicion, as apparently before the murder, a caller to Gilchrist's house had been looking for someone called "Anderson", and Slater had coincidentally previously been seen trying to sell a pawn ticket for a brooch. The police soon realised that the pawn ticket was for an entirely different brooch and a false lead, but notwithstanding the contradictory evidence, still applied for Slater's extradition. While Slater was advised that the application would probably fail anyway, he voluntarily returned to Scotland to clear his name of the alleged crime.
Trial of Oscar Slater
At his trial presided over by Lord Charles John Guthrie, whose summing up was highly prejudicial, defence witnesses provided Slater with an alibi and confirmed that he had announced his trip to America long before the date of Mrs. Gilchrist's murder. He was convicted by a majority of nine to six. In May 1909, he was sentenced to death, with the execution to take place before the end of that month. However, Slater's lawyers organised a petition that was signed by 20,000 people, and the Secretary of State for Scotland, Lord Pentland, subsequently issued a conditional pardon and commuted the sentence to life imprisonment. Slater was to serve nineteen years at Peterhead Prison. The following year, the Scottish lawyer and amateur criminologist William Roughead published his Trial of Oscar Slater, highlighting flaws in the prosecution. The circumstantial evidence against Slater included his alleged "flight from justice". The prosecution's evidence and witnesses identifying Slater as a suspect, including maid Helen Lambie, were also criticized as fleeting and otherwise unreliable, prejudiced, tainted, or coached. In particular, Slater was conspicuously contrasted with nine off-duty policemen in a rigged identification parade.
''The Case of Oscar Slater''
Roughead's book convinced many of Slater's innocence; influential people included Sir Edward Marshall Hall; Ramsay MacDonald; Viscount Buckmaster; and Sir Arthur Conan Doyle. In 1912, Conan Doyle published The Case of Oscar Slater, a plea for a full pardon for Slater. In 1914 Thomas MacKinnon Wood ordered a Private Inquiry into the case. A detective in the case, John Thomson Trench, provided information which had allegedly been deliberately concealed from the trial by the police. The Inquiry found that the conviction was sound, and instead, Trench was dismissed from the force and prosecuted on trumped-up charges from which he was eventually acquitted.
1927 saw the publication of The Truth about Oscar Slater by William Park. The contents of the book led the Solicitor General for Scotland, Alexander Munro MacRobert, to conclude that it was no longer proven that Slater was guilty. An Act was passed to extend the Jurisdiction of the then recently established Scottish Court of Criminal Appeal to convictions before the original shut-off date of 1926. Slater's conviction was quashed in July 1928 on the grounds that Lord Guthrie had failed to direct the jury about the irrelevance of allegations relating to Slater's previous character. After serving an almost two-decades long prison sentence of hard labour, Slater received only £6,000 in compensation.
Aftermath
Detective-Lieutenant Trench died in 1919, aged fifty, and never lived to see justice done. In the 1930s, Slater married a local Scottish woman of German descent thirty years his junior and settled in the seaside town of Ayr where he repaired and sold antiques. As an enemy alien, Slater and his wife were interned for a brief time at the start of World War II, though Slater had long since lost his German citizenship and never returned to Germany. Most of Slater's surviving family, including his two sisters, ultimately died in the Holocaust. He died in Ayr in 1948 of natural causes. The lessons of the Slater miscarriage were considered, as late as 1976, by the Devlin Committee review on the limitations of identity parades. More recently, the Slater case has been revisited by several scholars and writers.
