Lucy Letby, Harold Shipman and More: 6 of the Biggest Medical System Murders

Though most people don’t actively enjoy seeing doctors, medical professionals are typically associated with healing and care: a safe haven of sorts. But sometimes, the people we trust with our lives turn out to have sinister intentions. Hidden behind white coats and stethoscopes, some medical workers use their healthcare access and knowledge to betray their oath, taking the lives of the patients in their care. 

Many go unnoticed for years, their crimes blending in with the chaos of hospital life. Criminal medical professionals often prey on vulnerable populations like babies or the elderly, which makes it even harder for onlookers to notice what’s going on behind closed doors. 

In 2020, Lucy Letby, a neonatal nurse in the U.K., was charged with seven counts of murder and 15 counts of attempted murder. All of her victims were infants in the neonatal unit at the Countess of Chester Hospital. Prosecutors said Letby, 33 at the time of her August 2023 conviction, injected air into the bloodstream of many of the babies, ultimately killing them. She was convicted of killing seven babies and attempting to kill six others, receiving 15 life sentences and making her the fourth woman in British history sentenced to die in jail.  

During her 2023 trial, Letby insisted on her innocence, telling the court, “I only ever did my best to care for [the babies]” and that harming them was “completely against” everything she stood for. Despite this, serious questions persist about how she was allowed to continue working, and in July 2025, three hospital supervisors were arrested in an ongoing corporate manslaughter investigation related to leadership failures during Letby’s time at the hospital. 

Niels Högel, a German nurse, is considered one of the most prolific serial killers in modern German history. In 2019, he was convicted of murdering 85 patients between 2000 and 2005. He worked in hospitals in Oldenburg and Delmenhorst, where he would inject patients with drugs like ajmaline to trigger cardiac arrest, then try to resuscitate them in front of coworkers to appear heroic. 

His crimes came to light after he was caught tampering with a syringe driver, a small pump that delivers a continuous flow of medicine just under the skin. What began as an isolated case turned into a full-scale investigation, and although Högel initially admitted to 97 killings, his true number of victims could be as many as 300. He was sentenced to life in prison and told his victims’ families during the trial, “I would like to sincerely apologize for everything I did to you over the course of years.”  

Harold Shipman, nicknamed “Dr. Death,” was a respected British general practitioner until suspicions emerged over a high number of elderly female patients dying under his care. He often used lethal doses of diamorphine (medical-grade heroin) to kill his patients and forged medical records to make some of the deaths appear natural. 

The case broke open in 1998 when Kathleen Grundy, a healthy 81-year-old, was found dead at home soon after receiving a visit from Shipman. Her daughter became suspicious when a new will surfaced, leaving everything to Shipman and entirely cutting Grundy’s family out. This led to an exhumation of Grundy’s body, with forensic tests indicating that she’d actually died from a fatal morphine overdose.  

Further investigations linked Shipman to over 215 deaths, though estimates of his total murder count vary wildly; some estimates put the number of people he killed at around 215, while others claim he killed up to 345 people. In 2000, Shipman received 15 life sentences after being found guilty of 15 murders. He died by suicide in 2004. 

Charles Cullen was a registered nurse who worked in New Jersey and Pennsylvania from the 1980s until the early 2000s. During his time in the medical system, he murdered at least 29 patients by administering lethal doses of drugs like insulin and digoxin. Some believe his true number of victims may exceed 400. What’s especially disturbing about his case is that Cullen kept getting hired by new hospitals, even when there were overt red flags regarding his behavior. This can reportedly be attributed to a shortage of nurses at the time, and some hospitals failed to run extensive background checks on new hires. 

Cullen’s web of lies finally unraveled when a fellow nurse, Amy Loughren, grew suspicious of him and helped police gather evidence. Cullen was arrested in 2003 and later sentenced to 11 life terms. His story was detailed in the book The Good Nurse by Charles Graeber, which was adapted into a 2022 film. Cullen claimed some of his actions were “mercy killings,” but after speaking with Cullen multiple times while researching his book, Graeber told USA Today he believed killing made the former nurse “feel special and empowered, and it blew off steam.” 

Donald Harvey began killing patients in the 1970s while working as a hospital orderly in Kentucky and later in Cincinnati. He used a variety of methods, including cyanide, arsenic, suffocation and disabling life-support machines, often under the guise of easing patients’ suffering. Harvey also admitted he’d been angry at some of his victims. Though many of his victims were terminally ill, three of the people he killed were not his patients at all: one was an acquaintance, one was his roommate’s father and one was a neighbor. Harvey later admitted to at least 37 murders, though the true number may be higher. 

He wasn’t caught until 1987, when a suspicious coroner detected cyanide in one victim during an autopsy. An investigation led authorities to Harvey’s detailed diaries, as well as a stash of toxic substances. In a 12-hour confession, Harvey described his killings and revealed that he kept a list of victims hidden behind his bathroom mirror. Harvey received multiple life sentences and died in prison in 2017 after being attacked by another inmate. 

Linda Burfield Hazzard, known as the “Starvation Doctor,” was an early 20th-century practitioner in Washington State who promoted fasting as a cure for nearly any illness. Despite lacking a formal medical degree, she was licensed under laws for alternative healers.  

At her Olalla sanitarium, patients were subjected to extreme fasting—often limited to water and vegetable broth—which led to starvation and, in many cases, death. One of her most notorious victims was Claire Williamson, a wealthy British woman who weighed less than 50 pounds when she died.  

Many patients signed over money or property to Hazzard before their deaths. Between 1908 and 1913, up to 15 people died under her care. 

In 1912, following Williamson’s death and her sister Dora’s almost-death, Hazzard was convicted of manslaughter and served two years in prison. She later reopened her practice as a “school of health,” which burned down in 1935. Hazzard died in 1938 during one of her own fasts.