John Tawell (1784–1845) was a British murderer. In 1845, he became the first person to be arrested as the result of telecommunications technology.
Returning to England, he married a Quaker lady as his second wife. He confessed to the murder of his mistress, Sarah Hart, by prussic acid, his motive being a dread of their relations becoming known.
 Early life and criminal career
Tawell started out as a shopworker in London and for some years worked in a number of shops owned by the Quakers. At 22 he married Mary and worked in a chemist's. They had two children.
In 1814 Tawell forged a £10 note from Smith's Bank, a capital offence, for which he was sentenced to death. However, Smith's was Quaker owned and, being opposed to the death penalty, they had his sentence commuted to transportation. Tawell prospered in Australia where he opened a chemist's shop and his family joined him there in 1823. Tawell became a respected member of the Quaker community.
In 1831 the Tawell's returned to London. Both children soon died of tuberculosis in the polluted city. Mary fell ill in 1838 and also died by the end of the year. Tawell had employed a nurse, Sarah Lawrence, later to change her name to Sarah Hart, to look after Mary and now began an affair with her. This relationship bore two children and Tawell installed all three of them in a cottage in Salt Hill, Slough where he paid £1 per week to maintain them.
Tawell had kept Sarah Hart well away from his second wife, but by 1843 he was having financial problems and eventually decided to get rid of her. On 1 January 1845 he bought two bottles of Steele's acid, a treatment for varicose veins containing hydrogen cyanide, and travelled to Salt Hill where he poisoned Sarah while sharing a beer in her cottage.
 Arrest by telegraph
Between six and seven o'clock one morning in 1845 a woman named Sarah Hart was found dead in her home at Salt Hill, and a man had been observed to leave her house some time before. The police knew that she was visited from time to time by a Mr John Tawell, from Berkhamsted, where he was much respected, and on inquiring and arriving at Slough, they found that a person answering his description had booked by a slow train for London, and entered a first-class carriage.
The police telegraphed at once to Paddington Station, giving the particulars, and desiring his capture. 'He is in the garb of a Quaker,' ran the message, 'with a brown coat on, which reaches nearly to his feet.' There was no 'Q' in the alphabet of the two-needle instrument, and the clerk at Slough therefore spelt the word 'Quaker' with a 'kwa'. 'Kwaker' was understood, but only after several requests to repeat. Tawell was followed from the platform at Paddington by a seargent of the railway police, William Williams, who had put on a long civilian overcoat. Williams followed him into a New Road omnibus where Tawell mistook him for the conductor and gave him 6d for the fare. Tawell went to a coffee tavern and then home, all the while with Williams following. Willliams came back the following morning with Inspector Wiggins of the Metropolitan Police and they arrested Tawell in the same coffee house.
Tawell was tried for the murder of the woman, and revelations were made as to his character. His defense was handled by Sir Fitzroy Kelly, who tried to make a plausible case that the prussic acid that killed Sarah Hart was from eating the pips (pits) of apples (a large barrel of apples was in the house). The rather silly nature of this argument led the distinguished barrister to be known as "Apple-pip" Kelly for the rest of his life. Kelly also called a number of character witnesss to show that Tawell was well respected. One was the South Sea whale ship captain and explorer Peter Dillon.
Tawell was hanged in public on 28 March 1845 at Aylesbury with over 10,000 people watching. The notoriety of the case brought the telegraph into repute. Its advantages as a rapid means of conveying intelligence and detecting criminals had been signally demonstrated, and it was soon adopted on a more extensive scale. It was also the first known homicide case where the criminal attempted to flee the scene of the crime by a railway train.
- "Physiology in regard ot the laws of increase, and the influence of parents on offspring" Journal of Health and Disease, page 121, volume 1, November 1845
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- Tawell the Quaker — Glimpses into the 19th Century Broadside Ballad Trade