Matthew Hertgen, the New Jersey man accused of murdering his younger brother and a cat in a brutal attack last year, has died in custody. The 32-year-old was found dead in his cell at the Mercer County Jail on May 8 in an apparent suicide.
His death comes just weeks after a judge ruled he was not legally responsible for the February 22, 2025, killing of his brother, Joseph Hertgen, due to severe mental illness.
