John was hired in 1978 by the LACSD, where he began his career working in the Hall of Justice and then later in Inmate Reception. He started his patrol career in the Firestone Station, which was located at 7901 S. Compton Ave in the heart of a notoriously busy part of Los Angeles.
 
John later served for 10 years in the Special Enforcement Bureau (better known as SWAT) and then later the Advanced Officer Training Unit, the Marina Dive Rescue Team, and finally the Majors Narcotics Station Crew.