Authorities arrested a suspected gunman in the 2010 killing of U.S. Border Patrol Agent Brian Terry, officials confirmed to NBC News.
The killing exposed the U.S. Bureau of Alcohol, Tobacco and Firearms' operation to allow known drug traffickers to buy guns in order for the agency to track the illegal flow of weapons. But agents lost track of about 1,400 weapons involved in the operation, which was known as Fast and Furious.
Two of the lost guns were discovered at the scene of Terry's killing.
Heraclio Osorio-Arellanes was arrested in Mexico Wednesday in a joint operation of Mexican and American law enforcement. Arellanes is suspected of shooting and killing Terry, who was 40 at the time, during a firefight on the Arizona side of the U.S.-Mexico border in December 2010.