An unholy alliance is reshaping Los Angeles’ criminal underworld. Police have told The California Post once-sworn enemies MS-13 and 18th Street have set aside differences and decades of violence to form a “super gang,” cashing in on drugs, extortion and a booming underground casino trade that now rivals narcotics for profitability. The gangs are operating under the control of the Mexican Mafia , abandoning traditional tit-for-tat street warfare in favor of profit, coordination and expansion.