A New Jersey man was in a “fit of madness” and experiencing “terrifying visions” when, prosecutors allege, he murdered his younger brother, according to new details from the Mercer County Prosecutor’s Office.
An affidavit released Thursday details the day Matthew Hertgen, 31, is alleged to have killed Joseph Hertgen, 26, with a golf club and knife in a Princeton apartment. Both men are former college soccer players, Matthew Hertgen at Wesleyan University and Joseph Hertgen at the University of Michigan.
On Feb. 22, Matthew Hertgen called 911 and reported a fire and a dead body in his apartment, telling dispatchers his brother had been dead for over half an hour.
Princeton police found Joseph on the dining room floor with signs of blunt force trauma and a “large laceration to his chest and abdomen which exposed his chest cavity,” authorities said. His right eyeball was not visible, according to police, who found the presumed murder weapon and bloody utensils nearby Joseph’s body.
“Patrol officers observed a cup of what they believed to be blood, along with blood smeared eating utensils and a blood smeared plate on the dining room table,” the affidavit reads.
A cat was also found dead with signs of burns and blunt force injuries.
Matthew Hertgen, who had “abrasions and scratches” on his hands, told police he “went into a fit of madness,” authorities said. He was detained and taken to police headquarters, where he declined to speak with detectives.
A third Hertgen brother told investigators he had been with Matthew Hertgen earlier that day, describing him as “extremely distressed, despondent, and experiencing terrifying visions.”
Upon dropping Matthew Hertgen off at around 10 p.m., the third brother saw Joseph Hertgen and later texted him to “contact him immediately if he needed any help,” according to officials. He also reached out to Matthew Hertgen telling him to “hang in there” and invited him on a hike the next day. It was just over an hour later that Matthew Hertgen made the 911 call reporting Joseph’s death.
Matthew Hertgen had suffered from “severe mental illness” for five years, the third brother told officials. A poem posted on his Facebook account months before the murder describes knives, blood and pain.
He faces first-degree murder, third-degree animal cruelty and several weapons charges.
At a hearing Thursday afternoon in at Mercer County Court, Matthew Hertgen voluntarily consented to pretrial detainment. His next court appearance will be March 24, according to the judge.
