Bruce McKain talks to an author who believes he has solved the mystery who really murdered Marion Gilchrist in 1908

MORE than 80 years after the brutal murder of 82-year-old Marion Gilchrist the case of Oscar Slater retains its fascination as one of the great unsolved mysteries and major scandals in Scottish legal history.

Slater's fate is a sobering reminder that miscarriages of justice are by no means a recent phenomenon nor confined to the English legal system.

It has long been accepted that Slater was not the real murderer, and for many years suspicion has centred on Dr Francis Charteris, a relative of the elderly victim. Charteris died in 1964 after a distinguished career as Professor of Medicine at St Andrews University.

Now a former history teacher and Hong Kong policeman has written a book, confidently entitled Oscar Slater: The Mystery Solved, revealing in print for the first time the name of the man the author is convinced is the real killer.

Thomas Toughill also alleges that Slater was the victim not of a simple miscarriage of justice but of a conspiracy which extended to the highest levels of the legal system.

He claims that the prosecuting authorities hoped and expected that proceedings to extradite Slater from America would fail. Unfortunately Slater ruined the master-plan by volunteering to come back, certain that a fair trial would clear his name. His faith in the system was sadly misplaced and he was sentenced to death, saved from the rope only by a last-minute reprieve.

Slater was pardoned on the extraordinary condition that he spend the rest of his life in prison. The Government broke the terms of the pardon by freeing Slater after he had spent 18 years in Peterhead, then passed an Act of Parliament to allow him to appeal (successfully) against his conviction.

Mr Toughill, who is now looking for a publisher for his book, grew up in Glasgow in the late 1950s and the 60s when memories of the case were still strong. ''I thought it was probably the greatest Scottish murder mystery this century, let's have a crack at solving it. I believe I've done that.'' At this stage he does not wish to jeopardise the chances of publication by revealing the name of the killer but is certain that his researches have unlocked the key to the mystery.

''Dr Charteris was suspected for many years of being the murderer but although he was involved he was not the man who bludgeoned Miss Gilchrist to death in her Glasgow flat in December 1908.'' Mr Toughill is certain that the murder arose out of a family dispute over Miss Gilchrist's estate. Charteris was related to Miss Gilchrist's niece and she was originally the heir to the old lady's #80,000 fortune.

Towards the end of 1908 Miss Gilchrist, who had no love for the Charteris family, apparently changed her mind and decided to leave the great bulk of her money to a family called Ferguson, whose mother had at one time been her maid. ''There's no doubt that the whole reason for getting into that flat was to get hold of the will or a document,'' says Thomas Toughill. ''Time was urgent because Miss Gilchrist was dying from chronic kidney failure. Charteris was a doctor and may well have known this.''

Mr Toughill believes that Charteris was in Miss Gilchrist's flat with the killer and was seen leaving by Helen Lambie, the old woman's maid. He is also sure that Francis's brother, Archibald Hamilton Charteris, was waiting outside.

The official version is that Slater came to the attention of the Glasgow police on Christmas Day 1908, four days after the murder, but Mr Toughill has no doubt that this is a ''pack of lies''. ''Oscar Slater, a German Jew, was already known to the police as a pimp and a shady character. Slater himself claimed that the police had been keeping his flat under surveillance and that they in fact watched him leave Glasgow on his way to America.'' This was portrayed as a flight from justice but Slater had already made plans to leave Scotland for reasons unconnected with the murder.

Thomas Toughill thinks the police knew the identity of the real killer within hours and that like the Charteris brothers, he was protected by the authorities.

''Someone in the case pointed out the physical resemblance that existed between Slater and the Charteris brothers, in particular the curious dip at the bridge of the nose which the three men shared. A plot was hatched between Procurator-fiscal James Hart and John Ord, head of the CID, to blame Slater for the murder.

''The Charteris family was very influential. They were personal friends of Alexander Ure, who, as Lord Advocate, prosecuted the case.

''His performance at the trial was nothing short of disgraceful. Instead of taking an impartial view he conducted a ferocious assault on Slater's character. He invented facts and his jury speech was full of inaccuracies, all to Slater's detriment.

''As far as the extradition proceedings are concerned, the object was that they would fail. That's why the evidence produced at the proceedings was so weak. The Americans would never have returned Slater on the basis of that evidence. Mary Barrowman, a 14-year-old message girl, gave evidence that Slater merely resembled a man who had run out of Miss Gilchrist's close on the night of the murder. Helen Lambie said she did not even see the man's face. She recognised him by his walk.

''Failure to extradite Slater would have been the perfect solution. The authorities would obviously feign outrage and the Charteris family would be free to carry on with their lives. Slater spoiled the whole plan by volunteering to come back. He was outraged at this assault on his character and after all the hatred that had been whipped up in the press there was no alternative but to go ahead with the prosecution.

''Helen Lambie and Mary Barrowman were re-programmed and told to identify Slater as the man, whereas before they had merely said he resembled the man. In the late 1920s, just around the time that Slater was released, Mary Barrowman signed a statement stating that she had been browbeaten by the Procurator-fiscal into changing her evidence.''

Around the same time Helen Lambie was reported to have made a statement to the Empire News which seemed to point to Francis Charteris, not Slater, as the man she saw in her mistress's flat on the night of the murder. Thomas Toughill's book is dedicated to John Thomson Trench, the Glasgow policeman who tried to bring out the truth about the Slater case after the conviction.

The author says: ''I don't think Trench realised the extent of the conspiracy. He never had any chance of winning and was going to be squashed. That is why he was kicked out of the force and later prosecuted on a ridiculous trumped-up charge.

''An attempt was made to clear his name in 1969 while his widow was still alive but that came to nothing because of a lack of evidence. I don't see how anyone could read this book and conclude that there is no evidence. Trench was telling the truth. The man who walked aross that floor was Dr Francis Charteris and Trench was told that by Helen Lambie.

''Obviously I want my book to be published but I would also like to see justice done. Trench acted out of the highest motives. What he did was a remarkably courageous thing and his name should now be cleared.''