Matthew Hertgen, the so-called “Princeton cannibal killer,” has been found dead in his New Jersey jail cell in an apparent suicide, authorities confirmed.
Death at Mercer County Jail
Hertgen, 31, was found dead at Mercer County Jail on May 8, the Mercer County Prosecutor’s Office told NJ.com. The official cause of death has not yet been released. Hertgen had previously attempted to hang himself in his cell just a week after his arrest in February 2025.
Not Guilty by Reason of Insanity
Hertgen was found not criminally responsible for the murder of his brother, Joseph Hertgen, by reason of insanity. Mercer County Superior Court Judge Robert Lytle issued the verdict on March 19, 2025.
Details of the Crime
The horrific case involved Matthew stabbing and beating his 26-year-old brother to death with golf clubs in their luxury apartment. He then ripped out and consumed his brother’s eyeball. Following the murder, Hertgen set the family cat on fire. Joseph’s body was discovered by police lying in a pool of blood beside a knife.
Surveillance footage presented at trial showed Matthew assaulting his brother prior to the murder.
Mental Health History
Forensic psychologist Dr. Gianni Pirelli testified that Hertgen suffered from severe schizophrenia and experienced “prophetic and divine visions.” At times, Hertgen believed he was Jesus Christ, the anti-Christ, God, or possessed multiple souls.
“Anytime he closes his eyes, he’s seeing tremendous visions,” Dr. Pirelli said. Hertgen also believed the world was on the brink of an apocalypse and that only a “sacrificial murder could save it.”
His actions were reportedly influenced by a chapter in Swiss psychologist Carl Jung’s Red Book entitled “The Sacrificial Murder,” which Hertgen interpreted as justification for his actions.
Early Life and Background
Hertgen grew up in Toms River, New Jersey, in a $1.1 million home, and later moved with his family to the upscale Michelle Mews apartments. He had an idyllic childhood, excelling in soccer at Wesleyan University before his mental health issues emerged. Authorities say his struggles began in New York City in 2021.
Despite his crimes, Hertgen’s family remembered him as a “caring and loving person” in his obituary.
“During his later years, Matthew struggled with severe and profound mental health issues; yet he expressed sorrow, remorse, and repentance in many ways,” the obituary stated.
