Fired security guard tells CNN he stuck to his assigned duties . The man says the incident was a "nightmare" and that it left him with permanent brain damage. Federal official says CDC asked for Tate to be reassigned . Tate says he carried a handgun that he was given , never took photos of President on elevator .
Fired security guard tells CNN he stuck to his assigned duties . Kenneth Tate only went to take pictures when the detail was over , he says . Federal official says CDC asked for Tate to be reassigned . Tate says he carried a handgun that he was given , never took photos of President on elevator .