A shocking case in New Jersey has ended tragically with the death of a convicted cannibal killer in jail.
Princeton Cannibal Killer Found Dead
Matthew Hertgen, 31, was found dead in his Mercer County Jail cell on May 8, in what authorities are calling an apparent suicide. The Mercer County Prosecutor’s Office confirmed the death to NJ.com. An official cause of death has not yet been released.
Hertgen had previously attempted to hang himself a week after his arrest in February 2025.
The Heinous Crime
Hertgen was found not guilty by reason of insanity for the murder of his brother Joseph, 26. The verdict came on March 19, 2026, under Mercer County Superior Court Judge Robert Lytle.
During the attack, Hertgen stabbed and beat his brother with golf clubs, removed and ate his eyeball, and even set the family cat on fire. Joseph’s body was discovered by police in a pool of blood beside a bloody knife.
Mental Health and Insanity Verdict
Forensic psychologist Dr. Gianni Pirelli testified that Hertgen suffered from schizophrenia and experienced “prophetic and divine visions.” Hertgen believed himself to be Jesus Christ, the anti-Christ, God, or a being with multiple souls. He also thought the world was approaching the apocalypse and that a “sacrificial murder” could save it.
Pirelli noted that Hertgen was influenced by a chapter in Carl Jung’s Red Book titled “The Sacrificial Murder,” which he interpreted as justification for his actions.
Background
Hertgen had an idyllic childhood in a $1.1 million home in Toms River, New Jersey, before relocating to the Michelle Mews apartments. Despite his later actions, his family described him as a “caring and loving person.”
His obituary noted that Hertgen “struggled with severe and profound mental health issues; yet he expressed sorrow, remorse, and repentance in many ways.”
