- The condition was first described in 1923 by Joseph Capgras
- A person diagnosed with the disorder has delusions that an identical-looking impostor has replaced their spouse, friend, parent, or even a pet
Imagine sincerely believing that everyone around you is an impostor - would it be your best friend, mother or spouse? And the doppelgänger switches the bodies. One day it can be your wife, the other your pet! Some people do suffer from such a rare psychiatric disorder. Their intellect remains the same, and otherwise they see the world more or less normally. Below is the story of an anonymous patient who believed the identities of his family members were taken over.
John Doe was a 37-year-old white male who became delusional about the identities of his father, sister, nephew, brother and brother-in-law. He believed that his real relatives had died and that they were clones whose bodies had been taken over by spirits. He also found that the government was controlled by duplicates of former President Jimmy Carter, former first lady Rosalyn Carter, the United States senators and President Ronald Reagan. He heard voices informing him that the spirits who controlled his father’s body had killed his brother and substituted a clone in his brother’s place.
In fact, John Doe’s brother had committed suicide several years before. John Doe believed he had been assigned the task of God’s work by destroying the wicked people who had moved into the bodies of his family and others. For this reason, John Doe shot and killed his father and shot and severely wounded a nephew. He intended to kill other “cloned” relatives but could not find them.
While searching for his other family members, he saw a young man across the street and thought he was an accomplice of the evil impersonators. John Doe shot and wounded this young stranger as punishment for assisting in the murder and impersonation of his brother, an event that he delusionally believed had occurred.
John Doe was found not guilty by reason of insanity for one count of murder and two counts of attempted murder.
• • •The unnamed man was believed to be suffering from a delusion called Capgras syndrome. First described by Joseph Capgras in 1923, a person diagnosed with the disorder has delusions that an identical-looking impostor has replaced their close ones. The self-deception commonly occurs in patients with paranoid schizophrenia, but also in people suffering from brain injury, dementia, and neurodegenerative diseases.
The condition was first officially described in 1923 when Joseph Capgras’ patient “Madame M.” complained that a doppelgänger had taken over the bodies of her husband and friends. Dr. Capgras called the syndrome “l’illusion des sosies” - translated from French: the illusion of look-alikes.
Criminal Cases Involving Capgras Delusion
Not all people suffering from Capgras syndrome and paranoid schizophrenia are murderers, below are just a few samples of crime cases where delusions similar to Capgras were involved.
Niall Stapleton
Doctors had already diagnosed Niall Stapleton with paranoid schizophrenia, but like many others he did not accept the diagnosis and had a poor history of taking his medication. He believed the government plotted against him and wanted people to get addicted to these drugs, as part of a sophisticated scheme involving pharmaceutical companies to make money off of people’s addictions.
A day before these paranoid thoughts turned deadly, Niall attended a barbecue with his family. His behavior was described as paranoid and erratic by family members. He believed his sister’s boyfriend was putting LSD in his cans of beer and said that he was afraid to go to a barber fearing he might be held as a captive.
The next day, he saw his mother Siobhan in the garage and believed she was an impostor. By killing her, he felt the doppelgänger would disintegrate from her body. He butchered her by repeatedly beating her head with the handle of a shovel. Later, when revisiting the scene, he realized in horror that it wasn’t the Impostor he killed but his own mother.
Niall was arrested after the funeral and eventually admitted that he must have snapped and attacked his mother.

The jury of seven men and five women were satisfied with the claim that at the moment he was striking his mother, he truly believed he was striking a doppelganger. Niall Stapleton was found not guilty of murder by reason of insanity.
A short clip about a patient with Capgras Delusion
Blazej Kot
Blazej Kot killed his wife for similar reasons, but his insanity appeal was denied. He had been married to Caroline Coffey just months before the June 2009 murder. At the time of the killing, Blazej claimed to be under extreme stress. 60-to-80 hour work weeks and the couple’s mounting financial woes were contributing to an onset of paranoia and other symptoms associated with Capgras delusion.
He battered his wife’s head with an iron pipe and slashed her throat with a carpet-cutting knife, after which he set the apartment on fire and tried to get rid of physical evidence and computer records.
The jury didn’t buy the story presented by the defense that Blazej suffered from a mental disorder that made him think an impostor had replaced his wife. He was convicted of second-degree murder and all his insanity appeals have been turned down.
