The number of homicides in the United States' biggest cities continue to hit record lows again in 2013 with murder rates dropping to levels not seen in nearly a half century.

Los Angeles, the second-biggest U.S. city, reported this week that murders and other serious crimes dipped to more than 40-year lows in 2013. Total violent crime was down in the city 12 percent over the previous year.

Officials credit a citywide focus on prevention and intervention.

Crime rates in other US cities, such as Philadelphia, New York, and even Chicago, have also fallen to record lows, according to TIME magazine.

(READ the Reuters story from KFGO)