Some air passengers are about to face tougher security screenings before boarding flights to the U.S. The Obama administration is tightening security in an effort to find sophisticated explosives designed to get past screeners. Terror groups smuggled a shoe bomb and an underwear bomb years ago. Both plots failed. Jim Sciutto looks at how authorities are working to stay ahead of the terrorists.

Tom Ridge served as America's first Homeland Security Secretary. He says he believes terror groups in Syria are likely behind this latest threat.