Pileggi appeared in two episodes of ' as DEA agent Jack Hammond. Since 2008, Pileggi has played Ernest Darby, the head of a white supremacist gang called the "Nordics", in the FX drama "Sons of Anarchy" . He also played spree killer Norman Hill (AKA The Road Warrior) on a season four episode of "Criminal Minds", titled "Normal". Pileggi has also done some voice acting. His voice was featured as the githzerai Dak'kon in the video game '. He voices Commissioner James Gordon on the Kids WB! animated show "The Batman". Pileggi also hosted the controversial FOX specials "" and "Conspiracy Theory: Did We Land on the Moon?". He also played the recurring role of Sam and Dean Winchester's maternal grandfather, Samuel Campbell, in the TV series "Supernatural".