Mary Ann Cotton

One of my favourite historical figures is Thomas Scattergood, a forensic toxicologist based in Leeds. Britain’s “first” female serial killer, Mary Ann Cotton, was perhaps Scattergood’s most “famous” case. Mary Ann Cotton has been heralded as Britain first serial killer (murdered more than 3 people in under 30 days) by Professor David Wilson (criminologist), and was operating two decades before Jack the Ripper but seems to have fallen from history. The media frenzy around Mary Ann wasn’t anywhere near as intense despite her crimes. Perhaps because her murders weren’t as bloody or as quickly discovered, or because she was based in the north and the papers didn’t grab the headline as hard. When she went to court she rallied some sympathy because she was pregnant, this was further compounded when her execution was botched.

Second, it was readily available. Although by this stage, the authorities had started regulating the sale of arsenic, a high concentration could still be obtained in a substance known as ‘soft soap’, a household disinfectant.

There was a third reason, too: as Mary Ann well knew, the symptoms of arsenic poisoning were vomiting, diarrhoea and dehydration. A busy and unsuspecting doctor was always more likely to diagnose this cluster of symptoms as gastroenteritis or cholera– especially in patients who were poor and undernourished – than to suspect murder.

It is unclear exactly how many people Mary Ann murders, but it’s likely she killed 3 husbands, 1 lover, a friend, her mother, and 11 of her 13 children. According to the death and burial certificates, all her victims had died of gastric ailments. It seems she also played the role of the grieving wife and mother to perfection, making it all the more difficult to be precise about the number of people she may have killed. Her motivation was life insurance, she got about £35 for her first husband (6 months’ salary). She moved around a lot so her past seems to have been kept hidden in each new chapter of her life.

Eventually her actions caught up with her. In 1872, in the town of West Auckland in Co. Durham, her son Charles Edward died rather suddenly, and suspicion was compounded by the fact that Mary Ann visited the insurance office, not the doctor when he died. The newspaper’s got hold of the story and discovered the trail of death that haunted Mary Ann. her son had bee buried in the garden of the local GP Dr Kilburn. (it is unclear why they were buried there) and was exhumed along with three other potential victims.

Sgt Hutchinson clearly travelled to Leeds from Co. Durham, and Scattergood was careful to indicate chain of custody in his notes – the samples from various organs were actually received by someone called Lockwood, who was presumably an assistant, who locked them in his desk and took them out for Scattergood.

One of Scattergood’s note books contains details of the evidence he provided for the murder trial of Mary Ann Cotton. Scattergood was called in to confirm the suspicions of the local doctor and coroner, and conducted toxicological analyses of the remains of 4 individuals between 26 July and 16 October 1872, all of whom were proved to have been poisoned by arsenic. Scattergood’s notebooks show his analyses that he did on the samples of viscera (guts) received for the first victim, 7-year-old Charles Edward Cotton.

In the later cases he also analysed the soil in which the bodies had been buried. Organs examined included the stomach, bowels, liver, heart, lung, spleen and kidney. He also conducted a microscopic analysis of the contents of the second victim, Joseph Natrass’s intestinal canal (a former lodger with whom Mary Ann Cotton had an affair) as well as Reich Tests whose body parts arrived in a hamper.

This case occupies the 27 pages of the notebook. In fact the first page of this lengthy toxicological investigation details the tests that Scattergood made on his chemicals, to ensure their purity.

Mary Ann Cotton was executed at Durham Gaol on Monday 24 March 1873, five days after giving birth to her last child. Her execution was botched and the executioner was obliged to push down on her shoulders to finish it

On 14 March 1873, a week after Mary Ann Cotton’s trial, conviction and death sentence, Scattergood followed up on a point made by her defence counsel Mr Campbell Foster, that the arsenic in the bodies might have been due to arsenical wallpaper or accidental ingestion of a mixture of arsenic in soft soap (used for keeping insects at bay). He concluded that, regarding the wallpaper theory, “this would not account for the presence of solid AsO3 in the stomach”, while soft soap “could not possibly have been powdered any more than butter could have been powdered.”