Princeton Cannibal Killer Found Dead in Jail
Matthew Hertgen, a man once deemed not guilty by reason of insanity for killing his brother, was discovered dead in a New Jersey prison, apparently by suicide. His death occurred on May 8 at Mercer County Jail, with confirmation coming from the Mercer County Prosecutor’s Office on Friday. The exact cause of death has yet to be determined.
Hertgen had previously attempted suicide, trying to hang himself in his jail cell just a week after his arrest in February 2025.
At 31, Hertgen had been judged not criminally responsible for the murder of his brother by insanity, as ruled by Mercer County Superior Court Judge Robert Lytle on March 19. In a shocking act, Hertgen brutally stabbed his brother Joseph and subsequently bludgeoned him to death with a golf club in their luxury apartment. He then reportedly removed Joseph’s eyeballs and consumed them.
The incident also involved Hertgen setting fire to his cat, which further compounded the horror of his actions. Police found Joseph’s body surrounded by blood and a bloody knife after the tragic event.
Surveillance footage played during Hertgen’s trial depicted the assault in stark detail. Forensic psychologist Dr. Gianni Pirelli testified that Hertgen suffered from severe mental health issues, including schizophrenia, which led him to have delusions of grandeur, sometimes believing he was Jesus Christ, the Antichrist, or even God.
According to Pirelli, Hertgen experienced vivid visions that influenced his actions, making him believe that only such extreme measures could avert an impending apocalypse. In a disturbing twist, he was reportedly inspired by a chapter titled “Sacrificial Murder” in Carl Jung’s “Red Book.”
Hertgen’s struggles with mental health reportedly began in 2021 while he was living in New York City. Despite having a seemingly idyllic childhood in a lavish home in Toms River, memories from his family present a more complicated picture. They described him as a “caring and loving person” in his obituary but acknowledged his severe mental health challenges later in life.
Expressions of sadness and remorse were noted in the obituary, painting a picture of a troubled individual grappling with deep issues.
