NYPD's John Miller on Berlin attack, threat to U.S.
The Berlin Christmas market attack caused a visible increase in security in the U.S. Last month the State Department issued a travel alert on Europe, urging caution at "holiday festivals, events and outdoor markets." John Miller, NYPD's deputy commissioner of intelligence and counterterrorism, joins "CBS This Morning" to discuss the nature of the attack and whether there's an uptick in security threat to the U.S.