Homicide Detective Gustavo Carrillo has been employed by the Los Angeles County Sheriff's Department for twenty-three years, and assigned to Homicide for the past three years. He has handled over thirty homicides, and assisted in over twenty homicides in that time. While assigned to homicide, he has written over thirty cellphone and social media search warrants as part of his murder investigations. Prior to Homicide, he worked nine years with the Los Angeles County Sheriff's Department, Operation Safe Streets Bureau (Gang Unit.) Six out of the nine years with Operation Safe Streets Bureau, Detective Carrillo was assigned to the Los Angeles County Sheriff's Department, Homicide Gang Task Force, were he was the affiant in over seventy murder wiretap affidavits. In his preparation in writing these murder wiretaps, Detective Carrillo authored over two hundred search warrants for cellphone and social media accounts.

Detective Carrillo has taught at the L.A. Clear, Electronic Surveillance class. This course is a required 8-hour course for peace officers in qualifying individuals to intercept, record, and author wire communications (wiretaps.)