According to the Guardian's police shooting and police killing database, the Counted, there were 1054 police killings in 2016 across the nation. Of those, California had the highest number, at 156. Of the California victims, 140 were killed by gunshot, 2 by taser, 2 by being struck by a vehicle, and 12 were classified as deaths in custody.
The Wahsington Post is another source that compiles data of police killings. The Washington Post's Fatal Force data is different, but the tally still places California as the state with the highest number of fatal encounters with police officers. According to the Post, there were 940 police killings nationwide. California had the highest number, at 135, of which at least 29 victims were mentally ill or suffering from mental illness.
It is difficult to get accurate statistics on police killings because historically the reporting of such data has been voluntary. However, both federal and state inititaives are curently underway to remedy this and make reporting of police killings mandatory. Among the official efforts are the federal Death in Custody Reporting Act of 2013 and California's new Open Justice website.
For more information aboout police shootings in California, please see our page Police Shootings.
For more information on police shootings of people suffering from mental illness, please see our page Police Shootings and mental Illness.