The Mexican cartels are ramping up their firepower as reported by Camilo Smith for the San Antonio Express-News: "with AK-47s leading the list of favorite narco weapons, explosives are also increasingly part of their arsenal with items such as land mines and bazookas repeatedly on the list of weapons seized by officials."
The U.S. government supplied much of the heavy weaponry to the narco insurgents.
Through the gun walking investigation dubbed Fast and Furious the ATF inexplicably provided thousands of high-powered assault weapons without any tracking devices to the Mexican cartels including one used in the 2010 murder of border patrol agent Brian Terry. The Obama Administration continues its refusal to produce "more than 15,000 documents related to Operation Fast and Furious, including correspondence between Attorney General Eric Holder and his wife" as reported by Fox News.
Similarly, a scathing report from last October by a Justice Department Inspector General concludes that federal prosecutors and ATF agents botched their investigation of suspected arms smuggler Jean Baptiste Kingery who allegedly supplied grenade parts and other weapons from the United States to Mexican cartels as reported by Richard A. Serrano for the Los Angeles Times: "'the Kingery investigation suffered from flaws that we also observed in Operation Fast and Furious,' Inspector General Michael E. Horowitz said," and "Kingery should have been arrested and charged with violating the Arms Export Control Act."