Toms River Graduate’s Death: Brother Found Not Guilty Due to Insanity

Toms River Graduate's Death: Brother Found Not Guilty Due to Insanity

A former Toms River resident was declared not guilty by reason of insanity after killing his brother in their Princeton home with a golf club and removing his eyeball.

During a bench trial before Mercer County Superior Court Judge Robert Lytle on Wednesday, Matthew Hertgen, 32, was found legally insane in the murder of Joseph Hertgen, 27. Prosecutors claimed they were unable to challenge this ruling.

Lytle concurred with mental health specialists on both sides that Matthew Hertgen was legally insane when he killed Joseph on February 22, 2025. Hertgen was accused with first-degree murder, firearms charges, and animal cruelty.

Growing up in Toms River, the brothers attended Toms River North where they played soccer and graduated in 2011 and 2016, respectively. Both went on to play soccer in college, Joseph at the University of Michigan and Matthew at Wesleyan.

According to Dr. Gianni Pirelli, a clinical and forensic psychologist who assessed Matthew Hertgen and examined his medical records, Hertgen has suffered from severe mental illness since 2021 and is schizophrenic.

Matthew Hertgen will be detained until his sentencing on May 1 due to the not guilty by reason of insanity finding; after that, he is anticipated to be committed to a mental health hospital.