Lamson fought during the
Franco-Prussian War with the French Ambulance Corps during the 1871 siege of Paris, receiving a
Legion of Honour for his work. Lamson was tried at the Old Bailey in March 1882 before
Mr Justice Hawkins and a jury;
Montagu Williams acted for his defence: he was found guilty of murdering Percy in order to secure his share of the family trust fund, some £3,000 which Percy would have inherited on coming of age. He had poisoned his victim with
aconitine in the cake, a substance which Lamson had learned about from Professor
Robert Christison at
Edinburgh University. Christison had taught that aconitine was undetectable, but forensic science had improved since Lamson's student days and the poison was easily identified, as well as Lamson's purchase of it from a London pharmacist. Lamson's execution was delayed when
U.S. president Chester Arthur, Lamson was hanged by
William Marwood at
Wandsworth Prison on 28 April 1882, having admitted his morphine addiction and effectively his guilt of murdering Percy John. ==See also==