The Princeton, New Jersey, man accused of killing his brother and a family cat is set to appear in court for the first time Thursday.
31-year-old Matthew Hertgen faces first-degree murder charges in the tragic death of his 26-year-old brother, Joseph Hertgen. Additionally, he is accused of third and fourth-degree weapons offenses for being in possession of a golf club and a knife. Furthermore, he is also charged with animal cruelty concerning the passing of a cat.
Matthew Hertgen is scheduled to virtually attend a remote pretrial detention hearing in Mercer County. In New Jersey, due to bail reform, individuals facing criminal charges are either allowed to return home until their court date if charged under a summons, or they are held in custody if charged under a warrant until a pretrial detention hearing.
“Whether you will be detained or released is at the discretion of the prosecutor’s office, such as the Mercer County Prosecutor’s Office,” explained David Gelman, the CEO of Gelman Law and a former New Jersey prosecutor, in an interview with Fox News Digital. “If detention is ordered, a detention hearing will be held, akin to a miniature trial where evidence will be presented,” Gelman added, shedding light on the legal process.
General view of the Michelle Mews housing complex in Princeton, N.J., on Feb. 26, 2025. Matthew Hertgen is alleged to have murdered his brother, Joseph, inside their apartment on Saturday. (Kevin Downs for Fox News Digital)
Authorities have yet to describe any kind of motive related to Hertgen’s murder charges. The suspect had shared some disturbing, graphic poetry to his Facebook profile in September and May 2024.
Joseph Hertgen was pronounced dead at the scene, and his autopsy results are pending. Local and state officials are investigating the 26-year-old’s death as a homicide.
Joseph Hertgen was a University of Michigan soccer player. (Facebook)
Gelman said the community is shocked by the murder.
“This is something that is uncommon, and that’s probably an understatement.”
“Princeton is a very affluent area. … Homes there, minimum, you’re looking at probably 750[,000] and that’s probably like a little shack. So, you’re talking about some big-money areas. And the cops are … very prevalent there because they want to make sure that there’s no crime. It’s a safe area. You have a lot of private schools … so you’re talking about a very, very wealthy, affluent area in Princeton.”
Both brothers played college soccer: Matthew at Wesleyan University in Connecticut and Joseph at the University of Michigan.
An investigation into Joseph’s death is ongoing. Mercer County authorities are asking anyone with information about the alleged crime to contact the Homicide Task Force Sgt. Will Jett at 609-331-5010 or Det. Karl Johnson at 609-439-5258.
