Local prosecutors say they filed 20 cases in connection with offenses committed on the Mexican Mafia's orders, including a murder allegedly committed by a 15-year-old

Criminal charges were announced Tuesday against dozens of defendants who allegedly committed a host of violent crimes throughout San Diego County at the behest of the Mexican Mafia.

An expansive San Diego-area investigation into a gang whose tendrils spread into narcotics, weapons dealing, homicides and extortion led local and federal authorities to arrest dozens of people allegedly affiliated with the Mexican Mafia,