According to the report, there were 4.7 homicides for every 100,000 people last year, which is a 7.8 percent drop from 2009. It's the lowest rate since 1966.
It is also the fifth straight year killings have declined in California.
Among the 35 most populous counties, Monterey and Merced had the highest homicide rates at 10 per 100,000.
The Associated Press contributed to this report.