 That's ABC's Aaron Katursky in Crooks' hometown of Bethel Park, Pennsylvania. ABC Chief Law and Justice Correspondent Pierre Thomas has been talking to the head of the Secret Service. 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?