called atf headquarters. >> reporter: most agents didn't know about fast and furious. those who did, followed ordered. >> it was relaid to me, they didn't have to explain anything to me. i was to do as i was told. >> agent don johnson blew the whistle after the murder of brian terry. it ended the program, but not the carnage in mexico. >> a straw buyer would be arrested in the parking lot or down the street. these stores were recruited by the atf and u.s. attorney's office, multiple sales approved, no arrests, and no surveillance outside the store. >> when did you first know about the program officially i believe called fast and furious? to the best of your knowledge, what date? >> not sure the exact date. but i probably heard about fast and furious for the first time over the past few weeks. >> the timeline called into question, and the house of representatives actually voted to hold him in contempt of