Marianne Nölle was a carer in Cologne who looked after old people in their own homes. In 1993 the Cologne regional court sentenced her to life imprisonment for murder. The court found it proven that she had killed six people in her care between 1984 and 1992, and prosecutors said she had done it out of greed. Police believed the true number was far higher, but only six cases came to judgment. She denied the killings throughout the investigation, said nothing at her trial, and died in prison in 2022 at the age of 84.
The tabloid press called her the "Todesengel von Köln," the angel of death of Cologne. German newspapers reporting on the trial shortened her name to Marianne N., as the German press usually does with defendants; later reports, among them the Berliner Kurier in 2025, printed her full surname.
According to the Berliner Kurier, she was born in 1938. The Nürnberger Nachrichten, reporting on the verdict, gave her age at the trial as 57 and described her as an untrained carer. She was not a qualified nurse. She had a criminal record before any of the deaths came to light, with convictions for theft, fraud, forgery of documents and embezzlement.
None of the people who relied on her knew this. Her patients and their relatives did not know it, the Nürnberger Nachrichten reported, and neither did the family doctors who placed her with elderly patients or the health insurers who paid for her services. Suspicion had fallen on her before, the paper wrote, but it had never been firmed up.
Her work brought her into the daily lives of people who were old and often alone. She visited her patients at least once a day. She brought them meals, ran their errands and went with them to the doctor. Over time, the Nürnberger Nachrichten reported, she drew them away from their friends and acquaintances and won their trust, and with it their house keys and authority over their bank accounts.
That access was at the center of the case against her. Property belonging to former patients was later found in her possession. The Berliner Kurier, summarizing the case in 2025, listed what she took: jewelry, watches, cash, stamps and a condominium.
The six people whose murders the court found proven have never been named, and little is known of them as individuals. They were elderly people living in their own homes in Cologne who depended on her for help with daily life.
One of them, the woman whose death set off the inquiry, was 88. She had only the minor complaints of old age, the Nürnberger Nachrichten reported, and she hoped to live to 100. She kept her savings at home in a blue folder.
One day the 88-year-old woman fell suddenly into a coma. She was taken to hospital and died a few days later without waking. Her symptoms puzzled the hospital doctor, who asked her daughters whether their mother might have poisoned herself.
The daughters then found that her savings were gone. The only other person with access was her carer, Marianne N. The daughters went to the police.
The prosecutor's office ordered an autopsy. At first the cause of death appeared to be pneumonia. Behind the pneumonia, the examiners found, lay poisoning.
The Nürnberger Nachrichten described one earlier death that had raised questions and gone no further. She had been caring for the elderly father of a prosecutor, a man who called her by a pet name, "mein Mariannchen." While she looked after him, 10,000 marks went missing, and the blame fell on his cleaning woman. One morning he was lively on the telephone; at midday he was found dead on his sofa. His daughter-in-law wanted an autopsy. Her husband, the prosecutor, thought one unnecessary, and none was done.
Whether this death was among the cases tried in 1993 is not known; the court's findings covered only the six murders it held proven.
The police spent months gathering evidence after the daughters' complaint. Jewelry belonging to former patients was found in her possession, and when she was questioned about it she contradicted herself, the Nürnberger Nachrichten reported.
Prosecutors had the bodies of several of her former patients exhumed and tested for poison. The number of exhumations, their dates and the date of her arrest have not been made public.
Investigators came to believe that the deaths they could prove were a small part of the whole. According to the police figures reported at the time of the trial, they assumed 17 completed killings and 18 attempted ones. In its 2025 summary, the Berliner Kurier wrote that police suspected her in eleven further cases beyond the six for which she was convicted. None of those further cases was tried, and the court made no finding on them.
The trial took place before the Cologne regional court, the Landgericht Köln. The hearing of evidence lasted five months. The court heard 115 witnesses and six expert witnesses, the Nürnberger Nachrichten reported.
The defendant gave no evidence. She had denied the killings throughout the investigation, and in court she made no statement at all. With no confession, the case rested on the evidence the investigators had assembled: the poison found in her patients' bodies, the property found in her hands, and her own contradictory explanations.
The prosecution twice asked for life imprisonment for six murders committed out of greed.
In 1993 the court sentenced her to life imprisonment for murder. It held six murders, committed between 1984 and 1992, to be proven. According to the Berliner Kurier, she killed out of greed, and her victims died of poisoning with prescription drugs.
The exact date of the judgment, the name of the presiding judge and the name of her defense counsel have not been made public.
Marianne Nölle served her sentence in prison. She denied the killings for the rest of her life, according to the Berliner Kurier, and never admitted them. She died in prison in 2022, aged 84.
The Nürnberger Nachrichten, returning to the verdict 20 years later in 2013, used the case to show how easily a killing could be recorded as a natural death in Germany. It set the case beside a German study estimating that about 11,000 deaths a year in the country were wrongly certified as natural, and an estimate that at least 1,200 killings a year went undetected.
The paper described the weaknesses that made this possible. In most German states, any doctor could be called to examine a body and sign the death certificate, without special training; only a few states provided it. Doctors often wanted to avoid disputes with families, the paper wrote, and some fell back on "heart failure" as a routine cause of death. Autopsies were rare. The paper put the autopsy rate in Germany at barely one percent of deaths, against 20 to 30 percent in Scandinavia.
The paper also cited the journalist Sabine Rückert, whose book Tote haben keine Lobby ("The dead have no lobby") criticized the German system of death certification.
In January 2025, when a Berlin palliative care doctor was under investigation on suspicion of killing patients, the Berliner Kurier set out earlier German cases of medical staff convicted of killing the people in their care. Marianne Nölle's case was among them, alongside those of Niels Högel, a nurse convicted in 2019 of 85 murders at clinics in Oldenburg and Delmenhorst; Stephan Letter, the nurse the press called the "Todesengel von Sonthofen," sentenced to life imprisonment for killing at least 29 patients at a Bavarian clinic in 2003 and 2004; and a ward nurse in Wuppertal, Michaela R., sentenced in 1989 to eleven years for manslaughter and other offenses after deaths in intensive care.
The other cases on that list arose in clinics and hospital wards. Hers arose in her patients' own homes, where she worked alone.
The number of victims. The court found six murders proven. Police believed there had been 17 completed killings and 18 attempts, according to the figures reported in 1993, and the Berliner Kurier wrote in 2025 that police suspected eleven further cases. These higher figures are police suspicions. No court tested them, and they are not convictions.
The period of the killings. The court's findings, as reported by the Nürnberger Nachrichten and the Berliner Kurier, cover 1984 to 1992. An Italian magazine profile published in 2024 gave 1984 to 1991.
Her age. The Berliner Kurier gives her year of birth as 1938, while the Nürnberger Nachrichten gave her age at the trial as 57. The two reports do not match exactly.
The prosecutor's father. The Nürnberger Nachrichten described the sudden death of a prosecutor's elderly father in her care, with money missing and no autopsy. Whether that death was among the cases tried has never been made clear, and it is not among her known convictions.
The method. The court found that her victims died of poisoning. How the poison was given to them has not been made public.
1938: Marianne Nölle is born, according to the Berliner Kurier.
Dates not reported: she is convicted of theft, fraud, forgery of documents and embezzlement, before her murder trial.
1984 to 1992: the period in which the Cologne regional court later finds that she murdered six elderly people in her care.
Date not reported: the elderly father of a prosecutor dies suddenly while in her care; money is missing and no autopsy is done.
Date not reported: an 88-year-old woman in her care falls into a coma and dies in hospital; her daughters find her savings gone and go to the police.
Following months: an autopsy finds poisoning behind an apparent pneumonia; former patients are exhumed and tested; jewelry of former patients is found in her possession.
1993: trial before the Landgericht Köln; five months of evidence, 115 witnesses and six experts; she makes no statement.
1993: sentenced to life imprisonment for murder; six murders between 1984 and 1992 are held proven.
2013: the Nürnberger Nachrichten revisits the verdict and the weaknesses of German death certification.
2022: she dies in prison, aged 84, still denying the killings.
January 2025: the Berliner Kurier names her case among earlier German killings by medical staff.