A German doctor stood trial on Monday, accused of murdering 15 patients with lethal injections and assuming the role of “master of life and death” over those under his care.
The 40-year-old palliative care specialist, identified by German media as Johannes M., allegedly killed 12 women and three men between September 2021 and July 2024 while practising in Berlin.
Prosecutors say the victims, aged between 25 and 94, were injected with fatal combinations of sedatives. In some instances, the doctor reportedly set fire to their homes in an attempt to destroy evidence.
At the trial’s opening in Berlin’s state court, lead prosecutor Philipp Meyhoefer stated that Johannes M. carried out home visits under the guise of medical care, but did so with the clear intent to kill, abusing the trust placed in him as a medical professional.
“He acted without regard for human life,” said Meyhoefer. “He behaved as if he had the power to decide who lived and who died.”
Suspicion first arose in July 2024 when a colleague questioned the unusually high number of deaths, many involving fires. Authorities arrested Johannes M. the following month, initially charging him in four cases. Further investigation linked him to eleven more deaths, bringing the total to 15 charges of murder filed in April 2025.
Muscle Relaxant Caused Respiratory Arrest
The doctor allegedly administered a combination of anaesthetics and muscle relaxants to his victims without their knowledge or consent. Prosecutors explained that the muscle relaxant paralysed the respiratory muscles, causing the victims to stop breathing and die within minutes.
In five cases, Johannes M. reportedly started fires in the patients’ homes after administering the fatal injections.
On 8 July 2024, he allegedly killed two patients on the same day. First, he is said to have murdered a 75-year-old man in Kreuzberg. Hours later, he reportedly killed a 76-year-old woman in neighbouring Neukoelln and attempted to conceal the act by setting fire to her flat. The fire failed to spread, and Johannes M. allegedly contacted her relative, pretending to be concerned about her unresponsiveness.
In another case, prosecutors accused him of falsely claiming to have begun resuscitating a 56-year-old victim. Emergency responders managed to keep the victim alive temporarily, but the individual died three days later in hospital.
Investigation into 96 More Cases
Prosecutors revealed that a further 96 deaths remain under investigation, including that of Johannes M.’s mother-in-law, who had been battling cancer. She died under suspicious circumstances during a visit to Poland in early 2024.
Media reports noted that Johannes M. trained initially as a radiologist and general practitioner before specialising in palliative care. He submitted a doctoral thesis in 2013 exploring the motives behind serial killings in Frankfurt, opening with the question: “Why do people kill?”
Prosecutors maintain that he acted solely for the sake of killing and are seeking a life sentence. The court has scheduled 35 hearings, extending into early 2026.
Chilling Echoes of Past Cases
This case has drawn comparisons to that of Niels Hoegel, a former nurse sentenced to life imprisonment in 2019 for murdering 85 patients with lethal injections between 2000 and 2005 — the deadliest known serial killer in modern German history.
In 2023, another German nurse was sentenced to life for killing two patients by administering unprescribed drugs, while yet another nurse went on trial in March 2025 in Aachen for allegedly injecting 26 patients with high doses of sedatives or painkillers, resulting in nine deaths.
Just last week, police in northern Germany began investigating a doctor in Pinneberg, near Hamburg, suspected of killing several mostly elderly patients. Authorities confirmed they are reviewing multiple deaths linked to that case.