One of his most recent cases, challenging the male-only military draft, had come before Judge Esther Salas, whom Den Hollander had baselessly accused of delaying the case. In July 2020, Den Hollander arrived at the New Jersey home of Judge Salas, dressed as a FedEx delivery driver. When the door opened, Den Hollander opened fire. Judge Salas was in the basement at the time and was not injured, but her son was killed and her husband seriously injured.