Patrick Herbert Mahon was hung at Wandsworth in September 1924 for the murder of his mistress, Emily Beilby Kaye. Unintentionally, he had changed the Police’s crime scene investigation methods forever and presented Sir Bernard Spilsbury with the most challenging case of his career…

Mahon was a native of Liverpool, born in 1889 to a lower middle class family. He was a keen church goer, a Sunday school teacher and always a popular member of his community. He married his high school sweetheart, Jessie Hannah, in 1910 and then began a series of convictions and spells in prison that left Jessie with a daughter to provide for alone.

Jessie moved to Surrey whilst Mahon was serving a latter sentence in prison and began a job at a soda fountain manufacturers, where she was highly respected; So respected, that she managed to secure Patrick a position as a salesman with the firm when he was freed.

Mahon was a good salesman; he had the charm, the looks and a good head for business opportunities. During his course of business, he met and began an affair with a secretary at the London branch of the firm, Miss Emily Beilby Kaye. Miss Kaye was in her late 30’s, unmarried and fell deeply in love with Mahon. In the course of time, she pressed him to leave his wife and run away with her; something he was not prepared to do.

Emily Beilby Kaye

A bungalow was rented at a lonely stretch of shingle at Eastbourne, as a ‘love experiment’. Miss Kaye wished to prove herself to Mahon, prove that she could be a good wife to him, and hopefully persuade him to divorce Jessie and set up home with her. She was also pregnant; a fact that Mahon claimed not to have been aware of.

After a few days of the ‘experiment’, Mahon deposited a Gladstone bag at Waterloo station, and went about his business.

Meanwhile, his wife, Jessie, was becoming suspicious of her husband’s actions and whereabouts. She found the ticket for left luggage at Waterloo station, and she asked a friend of hers, a former Railway policeman, to accompany her to the luggage office and retrieve the bag. When the pair sneaked a look into the corner of the bag, their lives would never be the same again…. They replaced the bag and the ticket in Mahon’s pocket and then informed the police of their find

Little known to Mahon, when he collected the bag, the Police lay in wait for him. He was arrested on the spot on 2nd May 1924 and taken into custody. The contents of the bag included a bloodied knife, soiled lingerie and pieces of ripped bloodied material.

Events unfolded and Mahon told his story… He and Miss Kaye had become involved in a heated argument at the bungalow; she had hit her head on a coal scuttle in a struggle and died from the wound. Panicking – he hid her body in the spare bedroom for a few days, but eventually dissected the body into hundreds of pieces, disposed of some from train windows, he boiled some pieces of the body in a cooking pot, and hid some in biscuit tins and hatboxes in the cottage.


The Bungalow of Death.

Sir Bernard Spilsbury had the unenviable task of piecing together thousands of pieces of flesh, charred bones, and muscles of the dead woman, and claimed it was the most challenging case he had ever been involved with. When Spilsbury arrived at the bungalow, police at the scene were sorting through pieces of putrefying flesh and charred bone with their bare hands. Spilsbury saw this and created a ‘murder bag’, which consisted of gloves, tweezers, evidence bags, magnifying glass, ruler and swabs. This was created as a result of the gruesome ‘artefacts’ of this case. This bag is still used today at every homicide crime scene.


Due to overwhelming forensic evidence, Mahon was found guilty of murder and executed by Pierrepoint on 9th September 1924.

Apart from the case details, and newspaper reports of the time, I have also exposed an illegitimate child, born to Mahon’s wife, Jessie, in 1908 (2 years before their marriage). The child, grew up in an orphanage in Liverpool, and later moved to Surrey. I believe this was to be near her mother. This is a fact that is exclusive to my research, and I am in touch with the child’s descendants who have provided me with relevant documents.

I have also uncovered Patrick Mahon’s daughter, Patricia, and have documents to prove that she kept her father’s fate a secret, even from her husband for her whole life.

Jessie Mahon, died in 1974 in Surrey, and had never remarried.

Mahon was very popular amongst the female sex, who flocked in thousands to see him at each court appearance. His appearance and attire were commented on as much as his crime.


I am currently writing a full length book about the case.