One of the darkest tales from the North-East starts in County Durham in October of 1832. Mary Ann Cotton (nee Robson) was born in Low Moorsley, now part of Houghton-le-Spring in County Durham. Around even before the times of Victorian killer Jack the Ripper, Mary Ann Cotton is cited as Britain’s First Serial killer.

The British nurse and housekeeper who was believed to be Britain’s most prolific female serial killer, allegedly poisoned up to 21 people. For nearly a decade in the mid-Victorian era, Mary Ann Cotton poisoned a string of her husbands for their insurance money as well as anyone else who got in her way, including 11 of her own children.

Mary Ann also worked as a hospital nurse in nearby Sunderland, where she easily poisoned a handful of her victims.

Mary Ann’s downfall came when a parish official, Thomas Riley, asked her to help nurse a woman who was ill with smallpox. She complained that the last surviving Cotton boy, Charles Edward, was in the way and asked Riley if he could be committed to the workhouse. Riley, who also served as West Auckland’s assistant coroner, said she needed to accompany him. She told Riley that the boy was sickly and added: “I won’t be troubled long. He’ll go like all the rest of the Cottons.”

Five days later, Mary Ann told Riley that the boy had died. Riley went to the village police and convinced the doctor to delay writing a death certificate until the circumstances could be investigated.

Mary Ann’s first visit after Charles’ death was not to the doctor but the insurance office. There, she discovered that no money would be paid out until a death certificate was issued. An inquest was held and the jury returned a verdict of natural causes. Mary Ann claimed to have used arrowroot to relieve his illness and said Riley had made accusations against her because she had rejected his advances.

Local newspapers latched on to the story and discovered Mary Ann had moved around northern England and lost three husbands, a lover, a friend, her mother, and 11 children, all of whom had died of ‘stomach fevers’.

Rumour gave rise to suspicion and scientific investigation. Doctor William Byers Kilburn, who had attended Charles, had kept samples, and tests showed they contained arsenic. He told the police, who arrested Mary Ann and procured exhumation of Charles’ body. She was charged with his murder, although the trial was delayed until after the delivery in Durham Gaol on 10 January 1873 of her thirteenth and final child, whom she named Margaret Edith Quick-Manning Cotton.

Cotton’s trial began on 5 March 1873. The jury retired for 90 minutes before returning a guilty verdict. She was hung just under 3 weeks later at Durham Goal on 24 March 1873.

Over 100 years later, in the early 1990s, when Durham Jail was being modernised, the graves of some of those executed were disturbed, including that of Mary Ann Cotton. A pair of shoes belonging to her were found along with her bones. The bodies were removed and all were later cremated.