A controversial operation in which U.S. agents were allegedly ordered not to intervene as American guns flowed to Mexican gangs may have been going on for many years, reports CBS News investigative correspondent Sharyl Attkisson.
A photograph obtained by CBS News shows an astonishing display of high-powered weapons put up for suspected Mexican drug cartel gun buyers. It's a rare glimpse into ATF's controversial undercover operations.
The Bureau of Alcohol, Tobacco, Firearms and Explosives allegedly let gun runners walk off with weapons - thousands of them - to see if they'd end up in the hands of the cartels. The Justice Department and ATF have denied it ever happened.