Marie Becker was a dressmaker in Liège who, in her fifties, earned her living as a companion and private nurse to elderly women. In October 1936 she was arrested after an anonymous letter to the Liège prosecutor's office questioned the deaths of two widows she had known. After an investigation of seventeen months, she stood trial before the Liège Assize Court in June and July 1938. The jury found her guilty of eleven premeditated murders by poisoning, of attempted murder, of theft and of forging a will, and the court sentenced her to death. As was usual in Belgium at the time, the sentence was commuted to life imprisonment. She denied the charges to the end and died in Forest prison, in Brussels, in June 1942.
She was born Marie-Alexandrine Petitjean. Sébastien Baudart, writing for the Ghent archive Liberas in 2025, describes her as the daughter of a farming family in Flemish Brabant who made her way up to become a seamstress and dressmaker, and later a companion who also worked as a private nurse. Her exact date and place of birth have not been reported. She was 57 when she was arrested in October 1936, according to the same account.
She took her married name from her husband, who died in 1933, according to Liberas. Liberas gives no cause for his death, and his death was not one of the counts at her trial.
Writing for RetroNews, the press history site of the Bibliothèque nationale de France, Michèle Pedinielli describes her as a former shopkeeper who turned to work as a companion and nurse ("garde-malade") after money troubles. Many of the people in her care, Pedinielli writes, died not long after she began looking after them.
The deaths around her did not go unnoticed. In 1933, and again in 1935, the police received anonymous letters expressing surprise at the sudden deaths of two women close to her, according to RetroNews. Each time, the lack of evidence meant the matter was filed away.
A third letter reached the Liège prosecutor's office on October 12, 1936. As the French newspaper Le Journal reported on October 20, 1936, it raised the deaths, under "suspicious conditions," of two widows, aged 90 and 76. Without naming its subject, the letter pointed to a woman who had cared for them, and it also recalled the death of another widow the year before.
Money was at the center of the case, as RetroNews puts it, and money set off the judicial inquiry. Le Journal reported that she had tried to have one of her last patients make a will in her favor, and that this attempt helped draw the attention of the authorities. Once the inquiry was public, the paper added, fifteen families came forward to tell investigators about deaths they now regarded as suspicious.
The arrest came in mid-October 1936. The Liège investigating judge, Destexhe, issued the warrant for the 57-year-old woman, according to Liberas. Questioned, she admitted that she had known two of the dead women and that she had made tea for them, but she denied putting anything in it.
Early reports differed on what the police found. Le Journal reported on October 20, 1936, that a search turned up a small bottle hidden in a handkerchief, which the paper described as containing mercury oxycyanide. The case that went to trial rested on a different substance. According to Liberas, the poison at issue was digitoxin, sold under the name digitaline, a heart medicine, and she had a small bottle of it with her when she was arrested.
Police also recovered jewelry, trinkets and clothing that had belonged to the dead women, RetroNews reports. Le Journal reported that the homes of clients who lived alone had been emptied of valuables before their relatives arrived.
The investigation lasted seventeen months, according to both RetroNews and Liberas. By the time it closed, the prosecution was ready to charge her with eleven killings by poison. RetroNews gives the charge as eleven murders and five attempted murders; Liberas gives eleven counts of murder, with attempted murder, theft and forgery of a will.
The case was followed closely in the Belgian press. The weekly Pourquoi Pas? put her on its cover on June 24, 1938, in a drawing by Jacques Ochs, according to Liberas.
The trial began before the Liège Assize Court on June 7, 1938, according to Liberas. It lasted a little more than a month, with 25 days of hearings and nearly 300 witnesses, Liberas writes. Three lawyers defended her.
She denied every charge. The French newspaper L'Excelsior reported on July 1, 1938, on an exchange in court in which the presiding judge remarked that she seemed to be enjoying herself. "Yes, because these are lies," she replied, according to the paper.
As the hearings closed, her lawyer, Maître Chevalier, told the jurors that they would acquit her. The newspaper Le Populaire reported his words on July 6, 1938: "Vous allez acquitter Marie Becker" ("You are going to acquit Marie Becker").
The jury did not acquit her. On July 8, 1938, after about three hours of deliberation, it found her guilty of premeditated murder in eleven cases of poisoning, as well as attempted murder, theft and forgery, according to Liberas. Le Journal, reporting the verdict on July 9, 1938, gave the finding as guilty of the eleven murders and the five attempted murders.
The court sentenced her to death. At the bar she maintained her innocence; Le Journal quoted her as saying, "Je vous avoue que je suis innocente" ("I confess to you that I am innocent").
Her sentence was commuted to life imprisonment, as was usual in Belgium, according to Liberas; RetroNews also reports the commutation to life.
She appealed. The Court of Cassation rejected the appeal on January 31, 1939, according to Liberas, and the conviction became final.
She spent the rest of her life in prison. She died in Forest prison, in Brussels, on June 11, 1942, about four years after the verdict, according to RetroNews and Liberas. No cause of death has been reported.
Several points in the case remain uncertain.
The number of deaths. The jury's verdict covered eleven murders. Press reports in October 1936 spoke of more suspicious deaths, and Le Journal wrote that fifteen families had approached investigators. Deaths outside the eleven counts were never the subject of a verdict, and they cannot be attributed to her as fact.
Her husband's death. Her husband died in 1933, according to Liberas. He was not among the people she was convicted of killing, and no finding of any court connects her to his death.
The poison found at her arrest. The first newspaper reports described a bottle of mercury oxycyanide; the case at trial concerned digitaline. Which substance was found where, and when, has never been settled.
Her motive. Both RetroNews and Liberas describe the case as one driven by money: debts she ran up with the women she cared for, and hopes of being named in their wills. She never accepted that account and maintained her innocence at the verdict.
Born Marie-Alexandrine Petitjean, to a farming family in Flemish Brabant (date not reported).
1933: Her husband dies.
1933 and 1935: Police receive anonymous letters about the sudden deaths of two women close to her; each time the matter is filed for lack of evidence.
October 12, 1936: An anonymous letter to the Liège prosecutor's office raises the deaths of two elderly widows and recalls another death the year before.
Mid-October 1936: Arrested in Liège on a warrant from investigating judge Destexhe.
October 20, 1936: Le Journal reports the letter, the search and the approaches of fifteen families.
June 7, 1938: Trial opens before the Liège Assize Court, after a seventeen-month investigation.
June 24, 1938: Pourquoi Pas? puts her on its cover.
July 1938: The defense asks the jury to acquit.
July 8, 1938: Found guilty of eleven premeditated murders by poisoning, attempted murder, theft and forgery; sentenced to death, commuted to life imprisonment.
January 31, 1939: The Court of Cassation rejects her appeal.
June 11, 1942: Dies in Forest prison, Brussels.