"Grenade-walking" part of "Gunwalker" scandal

the investigation into the Bureau of Alcohol, Tobacco, Firearms and Explosives (ATF)'s so-called "Fast and Furious" operation branches out to a case involving grenades. Sources tell her a suspect was left to traffic and manufacture them for Mexican drug cartels. Police say Jean Baptiste Kingery, a U.S. citizen, was a veritable grenade machine. He's accused of smuggling parts for as many as 2,000 grenades into Mexico for killer drug cartels -- sometimes under the direct watch of U.S. law enforcement.