Unlike Dorothy Sayers, who wrote an engaging analysis of the Wallace murder in Liverpool, Agatha Christie is not usually thought of as a writer who was concerned, or drew direct inspiration from, “True Crime”. However, she did use actual criminality as a point of departure for several of her tales. The best known of these is the Lindbergh kidnapping (clearly discernible in “Murder on the Orient Express”). Others are explored in Mike Holgate’s “Agatha Christie’s True Crime Inspirations”. To me, the most interesting is “The Affair at the Victory Ball” (1923), an early Poirot case, with undeniable overtones of the Billie Carleton affair. This story concerning both cocaine and “fast” young women is one of the early fictional renditions of the set that Elvira was later to encounter.
Although not mentioned by Holgate, there is another Poirot story that may have been suggested by a real case – that of Elvira Barney. In her notebooks Christie writes,
“The Mares of Diomedes
Old racing man – his “gals” very wild – one of them shoots someone – (Mrs.Barney?)”
The story. which appeared as “The Horses of Diomedes” in “The Labours of Hercules” (1947), is about rich young women and cocaine.
“One night, Poirot is telephoned for help by a young medical acquaintance, Dr Michael Stoddart. Going to the address given to him, Poirot finds Stoddart in one of the flats where a party had been taking place before the medical man got there. The flat is owned by a lady called Patience Grace and the party involved the use of cocaine. Mrs Grace had an argument with her boyfriend, Anthony Hawker, and she attempted to shoot him as he left the flat……Stoddart’s concern is for Sheila Grant whom he met at a hunt ball in the country. She is one of four daughters of a retired army general and there is every sign that Sheila and her three sisters are starting to go wild, getting into a bad set where the cocaine flows freely. Sheila was at the party, is still at the flat having just woken up and is feeling terrible after the high of the drugs.” (from Wikipedia)
This does sound as if the germ of the plot was indeed the Barney case.
The original Horses of Diomedes fed on human flesh. In Christie’s version drugs and drug dealing fulfil the same function.
It has often been suggested that the mother and daughter, Lady Bess Sedgwick and the Honourable Elvira Blake, in Christie’s At Bertram’s Hotel are partly based on Elvira, for which a case, albeit a tenuous one, can be made.
There is nothing comparable to A Pin to See the Peepshow, by F.Tennyson Jesse about Edith Thompson, or Cause Celebre, by Terence Rattigan about Alma Rattenbury, that derives from the Mews shooting. But, given the sheer weight of detective novels churned out in the 1930s and the publicity surrounding the trial, it would not surprise me if other works of fiction utilised some aspects of the case.If anyone can confirm this, I’d be more than grateful.
More on fiction here https://elvirabarney.wordpress.com/2012/03/13/fiction/