In 1924, he was working as a lecturer in radio-telephony,[2] when he met Mabel Jones in Biarritz; she had gone there to recover from a breakdown.
On the morning of 29 March Alfred Jones came downstairs and took his habitual glass of Bromo-Seltzer as a hangover remedy from a bottle in the bar parlour, where Vaquier had already been sitting for some time.
[5] Vaquier was arrested three weeks later and a chemist in London identified him as the customer who had bought 0.12 grams (2 grains) of strychnine, signing the poisons book as "J. Walker".
The trial took place in July 1924 at Guildford Assizes before Mr. Justice Avory, with Sir Patrick Hastings as Attorney General (who traditionally prosecuted in person in poisoning cases[6]) and Sir Edward Marshall Hall for the prosecution;[7][8] Vaquier was defended by Henry Curtis Bennett.
He was found guilty and hanged by Robert Baxter at HM Prison Wandsworth.