On December 8, 1883, a family in Leiden ate a pot of porridge and fell violently ill: Hendrik Frankhuizen, thirty-five, his wife Maria van der Linden, forty-three, and their six-month-old son, also Hendrik. The doctor who was sent for, Braakenburg, did not come, but wrote a prescription on the strength of the description he was given. When he came on December 13 the mother was dead, and the baby died the next day. Another physician, Wijnand Rutgers van der Loeff, had by then seen the father, suspected poison, and had him taken to the hospital, where he died on December 19 after more than a week of agony. The bodies went to the anatomy department of the university, where Professor Teunis Zaaijer and his assistant opened them and removed the intestines, liver, stomach and kidneys into stoppered jars for a second professor, the chemist and toxicologist Eduard van der Burg. His tests found arsenic. The woman who had been looking after them was Maria van der Linden's sister-in-law, the neighbor everyone called Goeie Mie, Good Mie.
The Frankhuizens lived in an upstairs flat on the Groenesteeg, above a widow named Zitman. That Saturday they went into town with the baby, leaving a pan of barley porridge on the stove and the door open, as everyone did; nobody on the street owned anything worth stealing. While they were out, Swanenburg climbed the stairs with a cup of poison hidden under her apron and stirred it into the pan. She came down more noisily than she meant to, and called up the stairs as if she had only just arrived, but the widow had heard someone coming down before anyone called, and when she looked out, there was Goeie Mie with a long story about a message for her brother-in-law. The family came home at half past nine and ate the porridge, though it was yellow-red and harsh on the throat. He fell ill that night, his wife the next morning. Swanenburg went to church and then dropped by; the next day she came back, drank coffee and watched them get worse. "They're all three going to die," she told an acquaintance. She sat up with them through the night of December 11, tried to keep a doctor away, and finally sent her husband for Braakenburg. When Zitman said she was afraid to be left alone in the house with two bodies, Swanenburg laughed at her and promised to come back that afternoon and make a nice cup of coffee.
Maria Catharina Swanenburg was born in Leiden on September 9, 1839, the sixth child of Clement Swanenburg and Johanna Dingjan and the first of their daughters to live to adulthood. She grew up and stayed in the city's poorest quarter. Her father, by the Leiden police commissioner's later account, drank what little he earned, and the family was so poor that on Saturdays she and her sister sometimes had to stay in bed while their only clothes were washed and dried. Before her marriage she had three children; two died in infancy and the third was legitimized when she married Johannes van der Linden, an ironworks laborer, on May 13, 1868. They had seven children together, several of whom also died young, as children in that district commonly did. She earned her nickname by being the neighbor who always came, to mind children, to nurse the sick and old, and to see to the laying out and the funeral.
She was not at first a suspect. The police heard her as a witness. But on the morning of December 13 she had gone to Van der Worms, the agent of the burial society De Nederlanden, with whom she had insured Hendrik Frankhuizen back in 1880, and offered him a guilder and a half, and as much again later, to deny to anyone who asked that Frankhuizen was in the "dead fund." That evening she came back with two women and asked him, in front of them, whether Frankhuizen was insured; he said no, he told the court, to avoid a quarrel. Her husband was sent round on the Saturday to tell the agent's wife that her husband should say nothing and hand over no papers, and could name his price. Then a nephew of her husband, Izak Ouwerkerk, went to the station to talk about how many members of the family had died, and mentioned that it was always Goeie Mie who arranged the funerals. She was arrested that Saturday, December 15, 1883, with Hendrik Frankhuizen's insurance papers in her pocket. She denied having been upstairs at the Frankhuizens', changed her story when faced with what the widow Zitman had heard, and confessed the day before Christmas.
The mechanism the investigation uncovered was burial insurance, then a new and loosely run business. Agents asked few questions; anyone could insure anyone, without the insured person knowing, and with several companies at once. Swanenburg took out policies on neighbors and relatives, paid the premiums punctually so there would be no dispute, and collected when they died. Where there was property she also worked through inheritance, and the investigation concluded she had killed families in the order that brought the estate to her. She got the poison from a bedbug remedy sold by apothecaries as operment, mostly arsenic, which the druggist was supposed to stir into a pail of whitewash and which was easy to skim off at home; hers came, by the city archive's account, from the De Ruyter drugstore. To learn how easy it was, the police sent two plainclothes officers to a druggist, and against every rule they bought the loose powder for ten cents, enough to kill a hundred people. When little Suzanna Aben lay dying in her care, Swanenburg charged the family two guilders seventy-five a week for nursing and one guilder ten for laying out the body, and said she did not know where a doctor lived and could not bear to fetch one because the child was so ill; when the mother sent another woman, Braakenburg did not come and sent a draught instead. Doctors seldom came into the quarter, often prescribed without seeing the patient, and signed off deaths after a glance. Arsenic poisoning looked like the stomach illnesses that killed people there constantly.
The family register shows how close the deaths came. Her husband's sister-in-law Maria van der Mark died in October 1879, and his brother Lambertus in February 1881. His sister Cornelia van der Linden, a widow, died on May 30, 1881, and Swanenburg took in her three children. Willem de Hees died that July, and his older brother Arend on November 1, 1881, a date the court judgment gives as November 3. When only the youngest, Petrus Jacobus, was left, he was a soldier; poisoned, he dragged himself back to his barracks and into the military hospital, and she sent poisoned sandwiches after him. Two other soldiers who ate them fell ill with the same symptoms, and no one recognized arsenic. He lived and became one of the main witnesses against her. Her own mother died on April 16, 1882, her father on June 30, 1882, and her sister Petronella and Petronella's husband Johannes Lepelaar in the first months of 1883. Some of these deaths were among those investigated; not all were charged, and the order in which popular accounts list them varies.
The Leiden police spent a year and a half on the case. They interviewed dozens of neighbors and relatives, and bodies were exhumed and tested; accounts give thirteen or sixteen exhumations, with arsenic found in most. After her arrest she confessed to the Frankhuizen poisonings, and at different times blamed drink and claimed Hendrik Frankhuizen had made an indecent proposal to her. Zaaijer later published a forensic study of the exhumed bodies that disproved the common belief that arsenic poisoning mummifies a corpse. The judicial inquiry ranged over more than ninety suspicious deaths and illnesses. The popular figures of at least 102 people poisoned and 27 dead, sixteen of them relatives, are repeated widely but do not come from the court. At the trial her own lawyer, Vaillant, counted sixty-five poisoning attempts, of which twenty-four had killed.
The trial opened in The Hague on April 23, 1885, with fifty-one witnesses and six experts, foreign journalists in the room and a seat reserved for the United States minister. When she was brought in, a stifled cry of horror went up from the public. The prosecutor called her a creature unworthy of the name human. While she waited for trial she had tried to poison a fellow prisoner with zinc white, suspecting the woman of flirting with her husband on a visit, and witnesses recalled her laughing about the Frankhuizens' agony to an acquaintance. She broke down in court when the medical report was read and spoke of murders committed for pleasure. The prosecution charged only the cases it could prove best. The court found her guilty of poisoning committed three times, the third count covering the Frankhuizen couple together, so four named victims: her nephew Arend de Hees; a child, Suzanna Aben; and Hendrik Frankhuizen with his wife. The judgment records her own confession on the first count, that she killed the boy deliberately to collect the burial money due on his death, and the court accepted that motive. The judge also had sharp words for doctors who certified deaths without visiting the patient. Even Vaillant told the court there had never been a greater monster in the dock, and that he carried out his task with disgust and horror; he called her a psychic anomaly, an erreur de la nature, and questioned whether she could be held responsible, but the medical report ordered by the examining magistrate found she had acted in full possession of her faculties. She spoke no word of remorse, only one request on her own behalf: "A merciful sentence, please." The Netherlands had abolished the death penalty in 1870, and although many people, journalists among them, wanted an exception made for her, the prosecutor asked for life and on May 1, 1885, she received it, with costs, and an extract of the judgment was ordered posted publicly in The Hague and in Leiden. An appeal was lodged and then argued on no grounds at all. The figure of forty victims often printed with her name comes from an unsourced commentary paragraph that appeared beside the published judgment, not from the court.
She was held outside Leiden for fear that a crowd would storm the prison. On July 2, 1885, she was moved to the women's prison at 's-Hertogenbosch, and on March 8, 1887, to the women's prison at Gorinchem; she never came out. Her husband divorced her; the dissolution is dated December 29, 1885, in the city archive and January 29, 1886, elsewhere. The insurance companies went to court to recover what they had paid her and lost, because their policies had not excluded murder. Her children, who had done nothing, were shunned and called names in the street. After the case it became harder to buy strong poisons such as arsenic or to insure another person's life, and doctors became less casual about examining the bodies of poor patients in the working districts. Swanenburg died in the women's prison at Gorinchem on April 11, 1915, at seventy-five, and was buried in the Catholic cemetery there without a headstone. By the number of poisonings attributed to her she is counted among the most prolific killers in Dutch history, though the number the court established is three counts and four deaths.
September 9, 1839: born in Leiden.
May 13, 1868: marries Johannes van der Linden, an ironworks laborer.
1880: insures Hendrik Frankhuizen with the burial society De Nederlanden.
November 1, 1881: her nephew Arend de Hees dies (the court judgment gives November 3).
December 8, 1883: the Frankhuizen family eat porridge she has poisoned with arsenic; Maria van der Linden and her baby son die within days, and Hendrik Frankhuizen dies on December 19.
December 15, 1883: arrested with Hendrik Frankhuizen's insurance papers in her pocket; she confesses the day before Christmas.
April 23, 1885: her trial opens in The Hague.
May 1, 1885: convicted on three counts covering four deaths and sentenced to life.
July 2, 1885: moved to the women's prison at 's-Hertogenbosch, and on March 8, 1887, to Gorinchem.
April 11, 1915: dies in the women's prison at Gorinchem, at seventy-five.