Washington, DC - Experts warn of internal US terror threat

Washington, DC - With the recent arrests of terror suspects in Canada, there's a renewed focus on securing America's borders. But an FBI official warns the next threat to the U.S. could come from within.

Joseph Billy is the acting assistant director of the bureau's counterterrorism division. He warns of a possible "lone wolf" or maybe small groups of people, working inside the country, planning a terrorist act.