 There is no explanation whatsoever for how an individual was able to get on top of a building and be that close with a long rifle. All of the perimeters that needed to be in place, that outer perimeter is what the counter sniper team is responsible for. They're responsible for a long gunman or a long range rifle. So that question has to be answered. And CBS News national security contributor Samantha Vinograd says there may not have been many warning signs for those around Crooks.