The Case of Joseph Hertgen

Joseph Hertgen, a 26-year-old former collegiate soccer player, was found dead inside a Princeton, New Jersey apartment on 22 February 2025. Prosecutors allege his older brother, Matthew Hertgen, fatally attacked him with a golf club and knife before killing the family's cat. The case remains before the courts.

Joseph Hertgen and his older brother, Matthew Hertgen, were both accomplished soccer players who grew up in New Jersey. Joseph played collegiate soccer at the University of Michigan, while Matthew previously played at Wesleyan University. The brothers were living together in a luxury apartment complex in Princeton at the time of the incident. During the evening of 22 February 2025, authorities responded to the apartment after receiving an emergency call. Inside, officers discovered Joseph deceased from extensive injuries. Matthew Hertgen was taken into custody at the scene. Prosecutors later alleged that Joseph had been subjected to a prolonged and violent assault involving multiple weapons. Investigators also alleged that the family's pet cat had been killed and set on fire during or after the incident.

Police secured the Princeton apartment as a homicide scene. Investigators alleged Joseph suffered fatal blunt-force and sharp-force injuries. Court documents state that a golf club and a knife were used during the attack. The apartment contained extensive blood evidence consistent with a violent struggle. Detectives also recovered evidence relating to the death of the family's pet cat, which prosecutors allege was killed and burned inside the apartment. Forensic investigators collected biological evidence, weapons and electronic devices as part of the investigation.

The Mercer County Prosecutor's Office and Princeton Police Department launched a homicide investigation immediately following Joseph's death. Matthew Hertgen was arrested and charged with murder, weapons offences and animal cruelty-related charges. During subsequent court proceedings, questions were raised regarding Matthew Hertgen's mental health, and the case progressed through the New Jersey court system. At the time of writing, prosecutors allege Matthew Hertgen intentionally murdered his brother. As criminal proceedings remain ongoing, the allegations have not yet been tested at trial.

Matthew Hertgen has been charged with: - First-degree murder. - Multiple weapons offences. - Animal cruelty and related offences arising from the death of the family cat. The case remains before the New Jersey courts. No verdict has been reached.