A doctor’s main job is to heal people. They take an oath to do no harm. But what happens when someone trained to save lives decides to take them instead? It’s a chilling thought. Sadly, history shows us that some physicians have used their knowledge and skills for evil. They became serial killers, betraying everyone’s trust. Here are ten of the most disturbing cases of doctors who turned into murderers, using their medical expertise to commit terrible crimes.
10. Christopher Duntsch: The Rogue Spine Surgeon
They called him “Dr. Death.” Christopher Duntsch, an American neurosurgeon, had a horrifying record. He messed up 33 out of 38 surgeries. This wasn’t just bad luck. Duntsch barely finished his training, doing far fewer surgeries than normal. He also had a problem with cocaine, even going to a special program for doctors with addiction issues.
Once hired by Baylor Regional Medical Center at Plano in Texas, Duntsch quickly started harming patients. His first surgery left someone partly paralyzed. Others were maimed or severely injured due to his poor skills and lack of care. Over two years, he injured 33 patients. But he also killed.
In 2011, Duntsch operated on his friend Jerry Summers. The spine surgery went so wrong that Summers couldn’t move his arms or legs. He lived as a quadriplegic until 2021, when he died from an infection linked to the botched operation. Kelli Martin sought Duntsch’s help in 2012 for back pain. What should have been a simple 45-minute surgery turned into a three-hour disaster. Martin lost a lot of blood and died in the ICU.
Floella Brown was another victim. Duntsch cut a major artery in her spine during surgery at a Dallas hospital. This caused a massive stroke, and she was later taken off life support. Mary Efurd, a 74-year-old woman, was left paralyzed after an elective procedure by Duntsch. Finally, in 2013, after another surgeon complained about fixing Duntsch’s mistakes, his medical license was taken away. In 2017, Duntsch was found guilty of intentionally harming Efurd and sentenced to life in prison.
9. Linda Hazzard: The Fasting Fanatic
Long before extreme diets became trendy, Linda Hazzard was known as a “fasting specialist.” Shockingly, Hazzard had no medical degree. However, a legal loophole in Washington state allowed her to practice medicine. She wrote a book called Fasting for the Cure of Disease. Hazzard believed that most illnesses came from eating too much food and that strict fasting could cure them.
In 1902, she opened a health resort named “Hazzard’s Institute of Natural Therapeutics.” Patients there were given tiny amounts of broth or juice each day. They also received daily enemas. While some patients left feeling satisfied, it’s estimated that around 40 people died under Hazzard’s care. She dismissed criticism, saying those who died were already very sick.
In 1912, Hazzard was convicted of manslaughter. A wealthy woman died at her institute, weighing less than 50 pounds. Prosecutors proved Hazzard starved the woman while also stealing her jewelry and faking her will. She received a 20-year sentence but was pardoned by the governor after only two years. She then opened another sanitarium in 1920 and continued her deadly fasting practices until it burned down in 1935. Ironically, when Hazzard became ill in 1938, she tried her own fasting cure and starved herself to death.
8. Kermit Gosnell: The Abortion Clinic Killer
A grand jury report described Kermit Gosnell’s case bluntly: “This case is about a doctor who killed babies and endangered women.” The report stated he performed illegal, late-term abortions, delivering live, viable babies and then murdering them by cutting their spinal cords with scissors. Gosnell chillingly called this “ensuring fetal demise.”
Gosnell had been performing these illegal procedures since the 1970s. In 2011, a drug raid on his Philadelphia clinic uncovered a house of horrors. They found remains of fetuses and babies stored in cabinets, refrigerators, and even a garbage disposal. The clinic was described as filthy. Gosnell was accused of giving patients dangerous drug overdoses, spreading diseases with unsterilized instruments, and causing severe internal injuries. At least two women died because of his actions.
One victim, Karnamaya Mongar, 41, died from an overdose of Demerol given by Gosnell during an abortion procedure. Her 19-week fetus was later found in a freezer at the clinic. In 2013, Gosnell was convicted of three counts of first-degree murder for the deaths of the babies. He was also found guilty of hundreds of other abortion violations and involuntary manslaughter for Mongar’s death.
7. Harold Shipman: The Lethal Injector
Harold “Fred” Shipman’s dark path may have begun in his youth. As a teenager, he watched his mother die from lung cancer. He was reportedly fascinated by how morphine eased her pain. This experience seemed to spark an obsession with opiates for the future doctor.
In 1974, only a year after starting his medical practice, Shipman was caught forging prescriptions for Demerol for himself. After a small fine and a brief time in rehab, he returned to medicine. Over the next two decades, he built a reputation as a respected community doctor. However, a sinister pattern was emerging.
By 1998, concerns arose about the high number of deaths among Shipman’s elderly patients. Even a local taxi driver noticed that many healthy women died after he dropped them off at Shipman’s office. Kathleen Grundy was his last victim. Her will unexpectedly left her entire estate of £386,000 to Shipman, raising suspicion. Grundy’s body was exhumed, and tests found heroin. Investigators discovered Shipman had faked her medical records and created the will on his own typewriter. Further investigations revealed his method: he would give lethal doses of heroin, sign death certificates claiming natural causes, and falsify records. In 2000, Shipman was sentenced to 15 life terms for murdering 15 women between 1995 and 1998. It’s believed he killed more than 218 patients, making him Britain’s most prolific serial killer. He hanged himself in prison in 2004.
6. William Husel: The Fentanyl Overdose Doctor
Dr. William Husel, an intensive care doctor in Columbus, Ohio, was accused of murdering patients not with a scalpel, but with pain medication. In November 2018, Mount Carmel Health System removed Husel from patient care. They found that at least 34 deceased patients had been affected by his actions. From February 2015 to November 2018, 28 of these deaths were reportedly due to excessive, potentially fatal doses of medication ordered by Husel.
A hospital lawyer contacted the prosecutor’s office. The lawyer stated that Husel was giving fentanyl doses that the hospital believed were “inappropriate and not for a legitimate medical purpose.” An investigation revealed that these doses of the powerful pain-relief drug “were designed to hasten the death of the patients.”
Husel was charged with 14 counts of murder. Other cases involving smaller fentanyl doses were dropped, upsetting the families of those patients. One man shared that the doctor was supposed to make his loved one comfortable, not give a lethal dose like 1,000 micrograms of fentanyl. Husel’s trial ended in an acquittal. He later filed a defamation lawsuit against Mount Carmel, claiming severe damage to his reputation and asserting that all patient deaths were from natural causes.
5. H.H. Holmes: The Murder Castle Architect
Herman Webster Mudgett, who later changed his name to H.H. Holmes, showed his dark obsessions early. While studying at the University of Michigan Medical School, Holmes, driven by a fascination with death and money, stole bodies from the university. He would then disfigure them to look like accident victims and collect insurance money from fake policies he had taken out.
After medical school, Holmes worked in a Chicago pharmacy. He eventually bought the business; the previous owner’s widow mysteriously vanished shortly after. Across the street, he built a large, ominous hotel, which opened in 1891. Known as the “Castle,” it was marketed as a place for young women to find work and lodging. Holmes also placed ads seeking a wealthy wife.
He required employees, hotel guests, and his many fiancées and wives to have life insurance policies, with him as the beneficiary. Many of these insured individuals soon disappeared. Neighbors noted that many women entered the Castle but were never seen leaving. During the 1893 Chicago World’s Fair, Holmes lured many unsuspecting women needing a place to stay. His Castle had over 100 rooms, many soundproofed. The building also featured trapdoors, secret passages, peepholes, and chutes leading to the basement. The horrific basement contained a dissecting table, a stretching rack, and a crematory. Some victims were gassed in their rooms. Holmes would strip flesh from some bodies and sell the skeletons to medical schools. Others were cremated or dissolved in acid baths.
After the Fair, Holmes left the Castle and continued his scams and murders elsewhere. He was eventually arrested, and a police raid of the Castle uncovered numerous bodies and body parts. Though convicted of murdering an acquaintance’s children and confessing to 28 murders, investigators believe H.H. Holmes, one of America’s first documented serial killers, was responsible for up to 200 deaths. He was hanged in 1896.
4. John Bodkin Adams: Mercy Killer or Murderer?
Before Harold Shipman, there was John Bodkin Adams. This British doctor was at the center of a storm of suspicion. Between 1946 and 1956, over 160 of his patients died under questionable circumstances. Disturbingly, 132 of these patients had named Adams in their wills before they passed away.
In 1957, Adams stood trial for the murder of one such patient. Headlines screamed about the “Murder Trial of the Century” and “Massive Dosage of Drugs to Wealthy Widows.” He was accused of targeting elderly female patients, convincing them to change their wills in his favor, isolating them from their families, and then killing them with lethal injections of morphine and heroin. Despite the sensational claims, Adams was found not guilty of murder.
Even with the acquittal, the press continued to portray Adams as a villain. Some suggested police rushed the prosecution because they believed Adams had killed so many and would continue. While many saw him as a mass murderer, others believed he was performing mercy killings. They argued he administered painkillers to ease the suffering of terminally ill patients. Adams himself told police it wasn’t a crime to help dying patients suffer less. Whatever his motive, Adams became very wealthy, living in a large house and even driving a Rolls Royce that belonged to one of his deceased patients.
A later trial found him guilty of thirteen offenses, including prescription fraud, lying on cremation forms, and obstructing a police search. His medical license was revoked but reinstated in 1961. He continued practicing medicine until his death from natural causes in 1983.
3. Leonardo Cazzaniga: Italy’s “Diabolical Lover” Doctor
In April 2021, an Italian court confirmed the prison sentences for an emergency room doctor and his nurse lover, a pair dubbed the “diabolical lovers” by the press. Leonardo Cazzaniga, 65, was convicted of killing 10 people and received a life sentence. His mistress, nurse Laura Taroni, was sentenced to 30 years for murdering two family members. Both have been in prison since 2016.
Cazzaniga was found guilty of the voluntary manslaughter of eight patients at Saronno Hospital. Prosecutors argued that he killed in a “delirium of omnipotence,” giving his patients overdoses of anesthetic and sedative drugs. Police investigated about 40 deaths that occurred between 2011 and 2014 during Cazzaniga’s work shifts. One of these patients was Cazzaniga’s own father. His defense team claimed the drug use was standard palliative care. However, the prosecution highlighted that one victim died after being admitted for only a dislocated shoulder.
The doctor was also convicted of killing Taroni’s father-in-law and, together with Taroni, her husband. Taroni, a 44-year-old mother of two, was found guilty of murdering her husband and her own mother. A police wiretap recorded her saying, “From time to time, I want to kill someone. I need it.” She reportedly tricked her husband into believing he had diabetes and then gave him lethal doses of insulin. The couple is expected to file further appeals.
2. Shiro Ishii: The Germ Warfare Butcher
During World War II, many countries experimented with biological weapons, usually on animals. However, Japanese medical officer Shiro Ishii had no such ethical limits. He sadistically used human beings to test some of the deadliest germs known to science.
Ishii became a doctor in 1920 and joined the Imperial Japanese Army as a military surgeon in 1921. After the 1925 Geneva Protocol banned biological and chemical weapons in war, Ishii strongly encouraged the Japanese army to develop them anyway. He traveled to the U.S. and Europe, researching advancements in these horrific weapons.
In 1936, Ishii was put in charge of Unit 731 in China. This facility was supposedly for research to help Japanese soldiers, like studying how the body endures hunger, thirst, and disease. Early experiments used volunteers, but under Ishii, things changed drastically. He once said a doctor’s “God-given mission” was to treat disease, yet his work was “the complete opposite.”
At Unit 731, Ishii and his team performed horrific experiments on live human subjects. Chinese prisoners and Allied prisoners of war became his unwilling guinea pigs. They were forced to inhale, eat, or be injected with deadly diseases such as anthrax, smallpox, cholera, plague, and botulism. Researchers deliberately caused frostbite, forced pregnancies, and performed operations on live people without anesthesia. It is estimated that over 10,000 people died during these gruesome experiments. When the war ended, Ishii faked his death and hid. American forces found him and offered him immunity from war crimes prosecution in exchange for his research data. The U.S. accepted, but found little of value in his records. Biological weapons were not mentioned in the Japanese war crimes trials, and Shiro Ishii died a free man in 1959.
1. Josef Mengele: The Angel of Death
Before Josef Mengele became a notorious Nazi physician, he held doctorates in physical anthropology and genetic medicine. He even worked as a legitimate research assistant studying twins. However, Mengele fully embraced the racist and antisemitic beliefs of the Nazi party and sought to use his medical skills to further their twisted goals.
Mengele joined the Nazi Party in 1937 and earned his medical degree in 1938. By late 1943, SS Captain Mengele was the chief camp physician at Auschwitz II (Birkenau). There, he and about 30 other physicians regularly performed “selections” on arriving prisoners. They decided who would be forced into labor and who would be sent immediately to the gas chambers.
Mengele’s cruel and detached demeanor during these selections earned him the horrifying nickname “Angel of Death.” He would often appear at the selection ramp even when off duty, constantly searching for twins and people with unusual physical traits like dwarfism or different colored eyes. These individuals became subjects for his grotesque medical research. He had complete freedom to conduct agonizing and often lethal experiments, primarily on Jewish and Roma (Gypsy) twins, most of whom were children.
About 3,000 twins, mainly children, were subjected to his horrors. They endured daily blood draws and mass transfusions. Mengele injected chemicals into their eyes, trying to change their eye color. He would infect one twin with a disease and then kill both to compare their bodies. He performed spinal taps, castrations, organ removals, and amputations, all without anesthesia. Only about 200 of these twin children survived his experiments. Mengele was never arrested for his war crimes. He fled after the war and evaded capture for 34 years. In 1985, his grave was found in South America, and his body was exhumed, confirming his death.
These stories are a stark reminder that even those in positions of trust can commit unthinkable acts. The knowledge meant to heal was twisted into a tool for harm, leaving behind a legacy of pain and betrayal.
What are your thoughts on these disturbing cases? Do you know of any other similar stories? Share your reflections in the comments below.
