 There are still so many unanswered questions about the security failures at the scene, so we're now joined by A.T. Smith, a CBS News consultant who served as deputy director of the Secret Service from 2012 to 2015, and Samantha Vinograd, a former Homeland Security official and CBS News national security contributor. Good morning to you both. A.T., first to you, I want to show our viewers this video of the shooter. The police and the Secret Service knew that he was up there.