 Director of the United States Secret Service, Kimberly Cheeto, speaks exclusively with ABC News, taking responsibility for that stunning breakdown in security. This is an event that should have never happened. Who is most responsible for this happening? What I would say is that the Secret Service is responsible for the protection of the former president. So the buck stops with you? The buck stops with me. ABC News now learning that heavily armed local police were actually stationed inside the building. The gunman climbed, but they missed him.