In July 1872, a parish official in West Auckland, County Durham, named Thomas Riley asked Mary Ann Cotton whether she would help nurse a woman in the village who had smallpox. She said she could not, because of the boy. Charles Edward Cotton was seven, the last surviving son of her late husband Frederick, and she asked Riley whether he could be put into the workhouse. Riley told her he could go only if she went in with him. The boy was sickly, she said, and she would not be troubled with him long. "He'll go like all the rest of the Cottons."
On July 12, she told Riley that Charles was dead. By one account the boy had looked perfectly healthy six days earlier. Riley went to the village police and asked the doctor, William Byers Kilburn, to hold off on a death certificate until someone had looked into it. Mary Ann's first call after the death was not to the doctor but to the insurance office, where she learned that nothing would be paid until a certificate was signed.
An inquest was held at the Rose and Crown Inn on West Auckland's Front Street, next door to her house, and its jury returned a verdict of natural causes. Mary Ann said she had given the boy arrowroot to settle his stomach, and that Riley was making accusations because she had turned down his advances. That might have been the end of it. But the local papers had started asking questions, and what they found was a woman who had moved from one pit village and shipyard town to another across the North East and left behind her three husbands, a lover, a close friend, her own mother and a long line of children, nearly all of whom had died of what doctors called gastric fever. Kilburn had kept samples from the boy's body. When they were tested, they showed arsenic. Mary Ann was arrested on July 18, 1872, and charged with murder.
She had been born Mary Ann Robson on October 31, 1832, at Low Moorsley, near Hetton-le-Hole, the daughter of Michael Robson, a colliery sinker, and his wife, Margaret. When she was nine, in February 1842, her father fell 150 feet down a shaft at Murton Colliery. His body came home to her mother in a sack stamped as property of the South Hetton Coal Company. The cottage went with the job. Her mother remarried a miner, and at sixteen Mary Ann went into service as a nursemaid in a colliery manager's household, then trained as a dressmaker. The Wesleyan Sunday school superintendent at Murton remembered her, at the time of her trial, as a regular and exemplary pupil, notable for her clean and tidy appearance.
In 1852, at twenty, she married William Mowbray, a colliery laborer, at the Newcastle register office, and they went to the southwest of England for several years. Reports at the time of her trial said four or five of their children died young there. None of those deaths was registered; registration was compulsory on paper, but the law was not enforced until 1874. Back in the North East, their daughter Margaret Jane died in 1860, and a son, John Robert William, died of gastric fever at a year old in 1864. William himself died of an intestinal complaint in January 1865. The family was insured with the British and Prudential, and Mary Ann collected thirty-five pounds on her husband, about half a year's wages for a laboring man, and two pounds five shillings on the boy. A second Margaret Jane, three and a half, died soon after.
Working as an attendant at the fever hospital in Sunderland, she met a patient, an engineer named George Ward, and married him in August 1865. He was ill for most of the marriage, with paralysis and intestinal trouble, and died in October 1866. His doctor later testified that he had been surprised the end came so suddenly. She collected on him too.
Within weeks she was housekeeper to James Robinson, a widowed shipwright in Pallion. His baby, John, died of gastric fever a month after she arrived. She became pregnant by Robinson. Then she went to nurse her mother in Seaham Harbour through an illness, and her mother, who had begun to recover, started complaining of stomach pains and died nine days after Mary Ann got there. Mary Ann's surviving daughter from her first marriage, Isabella Mowbray, came back to the Robinson house and died, and so did two of Robinson's children, Elizabeth and James. All three were buried within about two weeks in the spring of 1867. She collected five pounds ten shillings and sixpence on Isabella.
Robinson married her anyway, that August. Their daughter Margaret Isabella was born that November and died in February 1868. A son, George, followed in June 1869. It was Robinson who first saw something. She kept pressing him to insure his life. He found that she had run up sixty pounds of debt behind his back, had kept more than fifty pounds he had given her to bank, and had been sending his older children to the pawnshop with household things. He threw her out and kept George.
She was on the streets when her friend Margaret Cotton introduced her to her brother Frederick, a pitman at Walbottle in Northumberland whose wife had died and who had lost two of his four children. In March 1870 Margaret died of a stomach ailment nobody could name. By one account Mary Ann had learned that Frederick stood to receive sixty pounds under his sister's will. She married Frederick at St. Andrew's in Newcastle on September 17, 1870, bigamously, since James Robinson was alive, and their son Robert was born early in 1871. When she learned that her old lover Joseph Nattrass was living free of his marriage in West Auckland, some thirty miles off, she moved the family near him. Frederick died of gastric fever that December. His life had been insured, and so had his sons'.
Nattrass moved in as a lodger. Mary Ann took a job nursing an excise officer through smallpox and became pregnant by him; he has come down in the popular accounts as John Quick-Manning, though no one of that name appears in the records, and a customs and excise officer named Richard Quick Mann does. In March 1872 ten-year-old Frederick Jr. died, then the baby Robert, then Nattrass, of gastric fever, shortly after changing his will in her favor. That left Charles, whose life was also insured.
The poison was easy to get and the illness was easy to mistake. Arsenic was sold over the counter, mixed with soft soap to kill bedbugs or into flypaper, and its symptoms, vomiting, stomach cramps, diarrhea, fever, looked like the gastric illnesses that killed working people constantly in those towns. She kept moving, and every marriage gave her a new name and a new doctor to sign the certificate. Post-mortems were rarely done on deaths that looked natural. By 1872 there was a reliable chemical test for arsenic, the Reinsch test, and after the arrest the police used it. The bodies of Charles, Frederick Jr., Robert and Joseph Nattrass were exhumed and examined by Thomas Scattergood of the Leeds medical school, and all four held arsenic. She was charged with four murders and tried for one, which was the practice of the time: a conviction on a single count meant death, and the others could be held back in case of an acquittal.
The trial was delayed while she was pregnant, and in January 1873 she gave birth in Durham Gaol to a daughter she named Margaret Edith Quick-Manning Cotton. The choice of prosecutor caused its own delay. The Attorney General, Sir John Duke Coleridge, passed over the barrister first considered, a Mr. Aspinwall, for his friend and protégé Charles Russell, and the appointment was questioned in the House of Commons. It stood. It was the first of the famous poisoning cases Russell would prosecute; Adelaide Bartlett and Florence Maybrick came later.
The trial opened at the Durham Assizes before Mr. Justice Archibald on March 5, 1873. Her counsel, Thomas Campbell Foster, argued that Charles had breathed in arsenic from the green wallpaper in the house, where arsenic compounds were used in the dye and cleaning with soft soap could raise a poisonous dust. It was not an absurd argument in 1873. Russell answered that at least ten of the people in question had never been in that room, and he could show that she had bought arsenic. An assistant chemist, Thomas Detchon, testified that on January 21, 1869, a woman came into his master's shop between two and three in the afternoon and asked for threepence worth of soft soap and arsenic to kill bedbugs. He told her he could not sell it without a witness and offered her a ready-made bug killer instead. She said she would rather have the other. She had given her name as Mary Ann Booth, and he identified her as the woman in the dock.
The jury was out, by most accounts, for about ninety minutes. Archibald put on the black cap and urged her to seek the only refuge left to her in the mercy of God. "Oh no! Oh no!" she cried, and she was carried from the dock. She wrote from her cell insisting she was innocent, and petitions for a reprieve went to the Home Secretary, some of them for the sake of the baby. He refused. Five days before the execution, Margaret Edith was taken from her and given to William and Sarah Edwards, a childless couple from Johnson Terrace in West Auckland.
She was hanged in the exercise yard of Durham County Gaol at eight in the morning on Monday, March 24, 1873, by William Calcraft and his assistant, Robert Anderson. In her last hours she told a minister that she might have killed the boy. Her last words were "Lord Jesus receive my spirit." The drop was no more than about two feet, and the rope was set too short, possibly deliberately. Her neck did not break. She struggled on the rope for around three minutes before she died of strangulation. The under-sheriff was reported to have fainted.
Twenty-one people close to her died in the twenty years before her arrest: three husbands, a lover, her mother, her sister-in-law, and children and stepchildren. Estimates of how many of them she murdered run from fourteen or fifteen to all twenty-one. Of the thirteen children she bore, two outlived her. One was Margaret Edith, raised by the Edwards family, who lived until 1954. The other was George Robinson, who survived because his father grew suspicious, put his wife out of the house, and kept his son.