Did the ‘South Croydon poisoner’ really get away with murder?

True crime author JEANETTE HENSBY on how a series of six mysterious deaths around a well-off family in the inter-war years drew her to investigate

When I was a child, my grandma told me how a friend of hers had confided that in the 1930s,her brother had murdered a girl.

I found an account of the crime in a book and was horrified to read that they appeared to have hanged the wrong man. I researched the case, uncovered a miscarriage of justice and wrote my first book The Rotherham Trunk Murder. That was it: I had caught the writing bug. The only problem I had was what to write about next.

After a bit of searching I found a very intriguing case that appeared to suggest that if you are a woman of great beauty and charm (and you know how to use it) who belongs to the upper-middle classes, you can get away with a string of murders which would see your average working-class labourer heading straight for an appointment with the hangman.

This would be the subject of my second book: The South Croydon Poisonings.

Grace Duff: ‘the devil incarnate’, according to some

Grace Duff was the granddaughter of Thomas Sidney, who had been Lord Mayor of London from 1853 to 1854. Being blessed with an abundance of beauty and charm, beautiful big blue eyes and the right social connections, she could have had her pick of men. Her choice was Edmund Duff, who she married in 1911 despite the disapproval of her family who considered him to be of lower social status.

After a career in the Colonial Services, Edmund Duff returned to England in 1919 after their seven-year-old daughter, Margaret, had died suddenly. He held a well-paid job in the Civil Service but in 1924, for reasons that are not known, he was dismissed from his post.

He had to take a lowly job as a clerk in a paper factory. Soon afterwards, the Duffs’ two-year-old daughter, Suzanne, became suddenly ill and died.

Mystery: Edmund Duff

Edmund was not one to accept the significant change in the family’s financial circumstances caused by his new employment, and he refused to change the lifestyle to which he had become accustomed. They were not without money because Grace’s father had left her with a substantial inheritance, but as well as his extravagant lifestyle, Edmund seemed to consider himself a whizz at financial investing – which he wasn’t. He was losing money hand over fist.

With mounting debts, Grace took the decision that they needed to downsize and they moved to a smaller house in South Park Hill in Croydon before making another move to 29 Birdhurst Rise, to be closer to Grace’s mother and unmarried sister.

The Duffs took in a lady of some financial means, Miss Anna Maria Kelvey, as a “paying guest”. Kelvey died suddenly and unexpectedly in January 1927, leaving gifts of £25 – worth around £1,500 in today’s terms  – to each of Grace’s two surviving children.

Did Grace decide a year later that Edmund’s profligacy with money was another problem that she needed to resolve? On April 23, 1928, when apparently in excellent health, he went to enjoy a short fishing holiday with an old Colonial friend. Within a day of returning home, on Thursday April 26, Edmund died in excruciating agony.

He was buried in Queen’s Road cemetery and after paying the funeral bills, there was nothing left in his estate. The two life insurance policies taken out on him, though, would help the family finances enormously: in today’s values, they equated to about £81,500.

Mystery: Anna Maria Kelvey

If Grace was indeed systematically murdering people, she certainly upped her game a few months after Edmund’s death.

In January 1929, her 40-year-old sister Vera started exhibiting signs of debilitating illness. After a family lunch on February 13, to which her Aunt Gwendoline was invited, Vera died an excruciating death, just as Edmund had done a few months earlier.

Aunt Gwendoline became seriously ill as well. She told anyone who would listen that she had been poisoned.

While Gwendoline survived, Grace’s mother Violet wasn’t so lucky.

After Vera’s death she also started exhibiting the same signs. She, too, was telling people that she was being poisoned, but nobody intervened to save her and 18 days after the death of her daughter Vera, Violet was also dead.

The interesting thing about this case is how Grace was treated. The coroner at the inquests into the deaths seems to have been completely in thrall to her. When she was in the witness box at the inquest into Edmund’s death, the coroner arranged for her to be provided with a pot of tea. Ever the bountiful lady, Grace insisted that the ladies in the public seats behind her had to be given tea as well.

How could all these deaths continue as they did? Was she, as some suspected, having an affair with Dr Elwell, the family doctor who dealt with all the deaths? Was he also involved in the murders?

Some, however, could see behind Grace Duff’s mask of feminine gentleness and charm.

William Fearnley-Whittingstall, the family’s legal defence counsel at the inquests, told his wife that Grace was the “devil incarnate”.

And why did the Reverend Deane, who presided at the death of two-year-old Suzanne, say that Grace appeared “quite unmoved and callous and not a bit like a mother”?

Did Grace use arsenic to poison those who died?

Was she ever charged and put on trial?

The answers to these and many more questions are all there in the book, as the account of this most intriguing and unusual case unfolds.

The South Croydon Poisonings, by Jeanette Hensby (pictured right) is available, £3.99 in paperback, from Amazon. Kindle edition 99p. Free to read on Kindle Unlimited

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About insidecroydon

News, views and analysis about the people of Croydon, their lives and political times in the diverse and most-populated borough in London. Based in Croydon and edited by Steven Downes. To contact us, please email inside.croydon@btinternet.com
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1 Response to Did the ‘South Croydon poisoner’ really get away with murder?

  1. TV Viewer says:

    Julian Fellowes in an episode of “A Most Mysterious Murder” (Touchpaper TV production) makes a very convincing case that the poisoner was the brother Tom Sidney as unlike the other suspects, he had the motive, means, and opportunity to commit each murder, and as a result was able to fund his family´s emigration to the USoA in order to follow his career as an entertainer which had fallen flat in England.

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