The worst female poisoner of all time, who is even listed in the Guinness Book of World Records, was Maria Catharina Swanenberg, better known as “Goeie Mie,” which means “Good Mia” in English. Good Mia is said to have been responsible for more than 100 victims, 27 of whom died. On September 9, 1839, Mia was born in the slums of the Dutch city of Leiden, the birthplace of the legendary Baroque artist Rembrandt. Leiden was an industrial city with a population of more than 48,000. Mia’s father toiled as a factory worker for 10 hours a day, six days a week. Despite this, he could barely support the family, who lived in a ramshackle shack, on his meager wages. Their main food was potatoes; that was all they could afford. When Mia’s father started drinking out of sheer frustration, the family soon could no longer pay the rent. They ended up on the street. Mia was already working at the age of 12. She babysat, cared for the sick, or did laundry for others. She helped wherever she could, which earned her the nickname “Good Mia.” After Mia gave birth to two daughters, she married Johannes van der Linden, a factory worker five years her junior, in May 1868. Mia’s life seemed to have finally taken a turn for the better. But the loss of six of her nine children in 11 years plunged her into a deep crisis. Like her father, she began drinking in 1877. In 1879, Mia began her career as a poisoner. Her deadly weapon was arsenic, a pesticide that was easily available. Mia purchased this at the De Ruyter drugstore in the form of a bedbug remedy. The arsenic powder was sold mixed with white lime; since this mixture was often not thoroughly blended, it was possible to skim off some of the poison. Mia did just that and poisoned her neighbors and acquaintances, and she did not even spare her own family members. Her victims died an extremely agonizing death. The victims endured diarrhea and vomiting coupled with cramps and pain, as well as confusion and visual disturbances, until their death from dehydration or organ failure. But why did Mia kill? Her motive was quite simple: greed! Mia took out funeral insurance policies on strangers, and a person could be insured multiple times. All she had to do was pay the premiums on time, which Mia did. So she eagerly insured her acquaintances, neighbors, and relatives. She then killed them with arsenic and collected the insurance payout. Afterward, she selflessly organized the funerals, from which she also profited. Through her murderous schemes, Mia amassed a small fortune. Mia also poisoned her sister-in-law Cornelia and her nephews Willem and Arend de Hees in 1881, which netted her 149 guilders. Piet, the nephews’ brother, survived. But as a concerned aunt, she sent him poisoned rolls to the hospital. People in Mia’s circle were dropping like flies, yet no one harbored even the slightest suspicion against kind-hearted Mia, who selflessly stayed by the victims’ deathbeds and cared for them until their deaths. Even when her neighbor’s daughter Suzanna and her cat—to whom Mia had given poisoned milk—died, no one suspected Mia. Since the victims came from the lowest social class, a doctor was often not called, and when one was, the examination was quite superficial. But over time, Mia began killing more and more people. At the neighbor’s daughter’s funeral, for instance, she poisoned all the mourners for no reason. The poisonings had become like a drug she could no longer give up. It had taken hold of her. She felt powerful when she killed someone. Mia poisoned little Hendrik, as well as his mother, Maria Frankhuizen, and her husband. Before he died, he managed to see a doctor, who suspected that the family had been poisoned and filed a report. In the course of the investigation, Mia came under the investigators’ scrutiny. A witness had seen Mia enter the Frankhuizen family’s home even though they were not there. Other witnesses testified that Mia often dealt with funeral insurance policies. Investigators searched Mia’s home, where they found a funeral insurance policy issued in the name of little Hendrik Frankhuizen. On December 15, 1883, Mia was arrested by the police. Shortly thereafter, she confessed to the murder of the Frankhuizen family, whose bodies were autopsied. In addition, 13 bodies were exhumed. All showed traces of arsenic. In total, the police investigated Mia for 1.5 years, during which they examined 90 deaths. On April 23, Mia’s trial began at the Court of The Hague. At first, she denied the charges. Then she admitted to having put some pepper or chlorine in the Frankhuizen family’s food because she wanted to make them sick. She wanted to take revenge for the Frankhuizen family’s father having sexually harassed her. Ultimately, Mia broke down and confessed to having poisoned the family with arsenic. Throughout the entire trial, Mia showed no remorse whatsoever. Even her lawyer, C.A. Vaillant, said in his closing argument that never had a “greater monster sat in the dock.” On May 1, 1885, Maria Catharina Swanenberg was sentenced to life imprisonment for triple murder, even though she had poisoned 65 people, 24 of whom died. Her appeal was rejected by the Court of Cassation on June 29, 1885. The trial made Maria Catharina Swanenberg world-famous; she went down in criminal history as the Poisoner of Leiden. On April 11, 1915, Mia died in the Gorinchen prison.



