Oscar Luzon is one of three detectives in the San Fernando Police Department working under Capt. Trevino. He is the oldest of the detectives but with the least experience. As of 2017 Luzon had just returned from a lengthy injured-on-duty leave. At the time of the La Familia Farmacia murders, Luzon had only been a detective for about six months. He had previously spent twelve years in patrol. He and the other detectives looked to Bosch for guidance because of his extensive experience with the LAPD.