It's one of the smallest law enforcement agencies in the federal government, but the Bureau of Alcohol, Tobacco, Firearms and Explosives has sure had a busy couple of weeks.
Dozens of its agents raced to Boston, where they analyzed bombs left near the finish line of the marathon. Others went south to Texas, where a fertilizer plant exploded under mysterious circumstances. Members of the ATF's national response team are still on the scene in tiny West, Texas, sifting through rubble at the blast site, near a crater that's 93 feet wide.