Park’s book sparked great interest on the part of the press: the time at last seemed to be right. In the years after World War I, the perceived threat to the genteel classes was shifting. By the 1920s, bourgeois anxieties, once focused on foreigners, had begun to attach themselves to first-wave feminism and the woman suffrage movement, socialism, and the dehumanizing use of technology. Amid these concerns, it seems likely that a lone, aging Jewish rogue did not cut the menacing figure he once did. What was more, most of the actors who might have been tarred by the public investigation of his case—including Lord Guthrie, the judge; Hart, the procurator fiscal; and Sheriff Millar—were now dead.
While the press interest was welcome, Conan Doyle knew that news coverage alone would not suffice. In September 1927, resolving to catch the attention of the British government at the highest level, he sent a copy of Park’s book to Ramsay MacDonald, who in 1924 had become Britain’s first Labour prime minister. Though the Labour government had been swept out of office by the Conservatives late that year, MacDonald, now the leader of the Labour Party, remained one of the most powerful men in Britain.*
In MacDonald, Conan Doyle found an influential ally. “I have been going further into the case and am quite convinced that this man has received a most horrible injustice and that the matter must be wound up, not only by releasing him, but by clearing him,” he wrote to Conan Doyle on September 26. “Everybody must be exceedingly grateful to you for the magnificent way you have stuck to the case, in [the] face of so much discouragement and apparent failure.”
Park’s book also moved the English journalist Ernest Clephan Palmer to action. Writing under the pseudonym The Pilgrim, Palmer produced a multipart investigative series on the Slater affair that ran in the Daily News of London from mid-September to mid-October 1927. “Each day Palmer attacked some fresh aspect of the case, the inaccuracies in the Lord Advocate’s speech, Mary Barrowman’s acrobatics, the almost lunatic behaviour of the murderer supposing that he was Slater,” Peter Hunt has written. “He tested Mary Barrowman’s story in West Princes Street and declared that her detailed description of the man running past her was impossible.”
On October 23, the Empire News, based in Manchester, published its own explosive story—touted in its pages, with noteworthy immodesty, as “one of the most dramatic developments in a criminal case ever recorded.” The article was a first-person account by Helen Lambie, who had disappeared from Scotland and was widely presumed dead. The Empire News had found her, living with her husband in America, near Pittsburgh. Her story, stemming from an interview with her there, appeared under the headline “Why I Believe I Blundered over Slater.” It read in part:
It has been said and denied that when first questioned by the police as to whether I had any idea of the identity of the man leaving the house of my mistress on the evening of the murder, I mentioned the name of a man who was in the habit of visiting here.
It is quite true that I did so, because when I returned from buying the evening paper and encountered the strange man coming from the house he did not seem strange to me.
Otherwise, I should have wanted to know more about his presence there….
When I told the police the name of the man I thought I recognised they replied “Nonsense! You don’t think he could have murdered and robbed your mistress!” They scoffed so much at the notion of this man being the one I had seen that I allowed myself to be persuaded that I had been mistaken….
I had my reasons for not looking too closely. The man I thought I saw coming out of the flat had been visiting Miss Gilchrist on another occasion, and I happened to mention his name to my mistress afterwards.
She flew into a temper with me and told me that if I ever displayed the slightest curiosity again about any of her visitors she would discharge me….
There were many circumstances to make it easier for me to accept the notion that Slater was the man….Moreover, we were told that he had been caught trying to escape to America with some of the property of my mistress….
I am convinced that the man I saw was better dressed and of a better station in life than Slater. The only thing they had in common was that when standing end on the outlines of the faces from the left were very much the same.
“What a story!” Conan Doyle wrote afterward. “What a scandal! She says that the police made her say it was Slater. Third degree! What a cess pool it all is! But we have no words of hope from those wooden-headed officials. I shall put on the political screw and I know how to do it. I’ll win in the end but it has been a long fight.”
Park, meanwhile, was trying to locate Mary Barrowman, who had vanished into the Glasgow slums and was believed to have become a prostitute. “She is in the streets & has been in prison,” he wrote to Conan Doyle in the autumn of 1927. “A denial from her would finish the Crown case.” Assisted by Palmer and an unnamed ex-convict, Park found her, and on November 5, 1927, the Daily News printed her recantation:
I, Mary Barrowman, who was a witness at the New York proceedings and at the trial in Edinburgh, desire in the interests of justice to make the following statement: …
Regarding the proceedings at New York, where I was confronted with the prisoner for the first time…I did not feel warranted in then saying after my viewing of him, that Oscar Slater was positively the man I had seen coming down the steps of the house in West Princes Street where Miss Gilchrist was murdered.
I only thought at the time that he was very like the man I had seen, and I did not say in my identification that he positively was the man.
It was when I returned to Glasgow that the question of Slater being positively the man was brought before my notice. This was done by Mr. Hart, the Fiscal.
This gentleman was most severe in his treatment of me as a witness. He made me appear at his office day after day to have a meeting with him.
I should say that I was in attendance at his office for the purpose of going over my evidence on at least 15 occasions. I am positive that is an under- rather than an overstatement of the number of my appearances in his office.
It was the same routine every day. He went over my evidence, himself doing all the talking and I for the most part listening. He was so much the director of the things that were to be said that I had no opportunity or very little to have my say.
It was Mr. Hart who got me to change my statement from being “very like the man” to the emphatic declaration that Slater was the man.
The furthest I wanted to go was to say he was very like the man, and it was Mr. Hart who really used the words “the man,” and applied them to my statement.
I want to state most definitely that I thought Mr. Hart’s demeanour was not what it should be. He was the party who was laying down what was to be said….
I was just a girl of fifteen years of age then, and I did not fully appreciate the difference between saying that Slater was the man instead of very like the man; and if I had it to say now all I would declare is that he was very like the man—and that is what I said when I first saw him.
The recantations made it impossible for the government to stonewall Slater’s supporters any longer. On November 10, Sir John Gilmour issued a statement: “Oscar Slater has now completed more than eighteen and a half years of his life sentence, and I have felt justified in deciding to authorise his release on license as soon as suitable arrangements can be made.”
The news reached Slater on the prison bush telegraph. Reverend Eleazar Phillips, his champion from the beginning, was summoned in secret to Peterhead to escort him out. On Monday, November 14, 1927, at 3:00 p.m., the gates that separated the prison from the world swung open, and Oscar Slater passed through them, after eighteen years, four months, and six days, a free man.
* MacDonald would serve as prime minister again between 1929 and 1935.