Between 2009 and 2011, the Bureau of Alcohol, Tobacco, Firearms, and Explosives allowed the illegal purchase of guns to known criminals in Arizona with the hopes that the weapons would lead them to Mexican drug cartels as they made their way across the border.

When the government lost track of some 1,700 guns, and weapons showed up in Texas instead of Mexico, the project, dubbed Operation Fast and Furious, was in trouble. But, after one of the AK-47s that was purchased resurfaced at the scene of the murder of U.S. Border Patrol agent Brian Terry in Arizona during December 2010, the program was officially terminated. While it is unconfirmed, Mexican officials say that 150 Mexican citizens have been killed or wounded by guns trafficked by Fast and Furious. 

Two similar programs were overseen by President George W. Bush—Operation Wide Receiver and a 2007 probe.