High Quality Content by WIKIPEDIA articles! The Newhall massacre or Newhall Incident was a shootout between two heavily armed criminals and officers of the California Highway Patrol (CHP) in the Newhall unincorporated area of Los Angeles County, California on April 6, 1970. In less than 5 minutes, four CHP officers were killed in what was at the time the deadliest day in the history of California law enforcement.