ATF Special Agents Dobyns and Kilday put their best feet forward only to have their lives put on the line, in this clip from Undercover: Caught on Tape. | Crime & Investigation on A&E

12K views · 105 reactions | Undercover ATF Agent Dominick Polifrone dives into the chilling journey to expose alleged serial killer Richard "The Iceman" Kuklinski, who was suspected of claiming at least 5 victims. Undercover: Caught on Tape | Thursdays at 10/9c #UndercoverAE | Crime & Investigation on A&E | Facebook

Known as the "Hillbilly Donnie Brasco," FBI agent Scott Payne risked his life to expose violent neo-Nazi cells threatening national security, including the KKK and biker gangs. In 2019, he embedded himself with US extremist groups as part of an FBI investigation to avert a mass shooting planned by a white nationalist group called The Base. Payne talks to Business Insider about undercover protocol, creating legends, whether agents use burner phones, the ethics of undercover work, and surveillance