The Newhall incident showed that none of the California Highway Patrol officers were not wearing bullet proof vests, used .357 ammo not .38 ammo, and all four officers had two years or less experience on patrol.

https://en.wikipedia.org/wiki/Newhall_incident

Reenacted video:

http://www.bluesheepdog.com/2012/09/28/newhall-shooting/