Newhall incident

The Newhall incident, also called the Newhall massacre, was a shootout on April 5–6, 1970, in Valencia, California, United States, between two heavily armed criminals and four officers of the California Highway Patrol (CHP). In less than five minutes, the four CHP officers were killed and another man was pistol-whipped in what was at the time the deadliest day in the history of California law enforcement.

At about 11:54 p.m. on April 5, CHP officers Walt Frago and Roger Gore conducted a traffic stop of Bobby Davis and Jack Twinning in conjunction with an incident reported to the CHP minutes earlier. Davis and Twinning initially cooperated with the officers but then opened fire, killing both of them. Moments later, officers George Alleyn and James Pence arrived on the scene and engaged the perpetrators in a shootout. A bystander tried to help by firing an officer's weapon, but the three were outgunned. Both Alleyn and Pence suffered fatal injuries, while the witness ran out of ammunition and took cover in a ditch. A third CHP patrol car arrived on scene, and the officers briefly exchanged gunfire with the perpetrators, who then fled.

Davis stole a car and attempted to flee the area but was spotted by police and arrested. Meanwhile, Twinning broke into a house, taking the occupant hostage. The house was surrounded by deputies of the Los Angeles County Sheriff's Department, and Twinning released the hostage. He committed suicide around 9 a.m. as the deputies entered the house.

In 1972, Davis was convicted and sentenced to death for the murders. His sentence was later commuted to life imprisonment without the possibility of parole. Davis committed suicide at Kern Valley State Prison in 2009.

The Newhall incident resulted in a number of changes at the CHP, including procedural changes for arresting high-risk suspects, standardization of firearms and firearms training used throughout the department.