Best known for his pivotal role in founding the notorious "Hell's Angels" biker club, Ralph "Sonny" Barger made headlines for his participation in the infamous Rolling Stones-Jefferson Airplane concert at Altamont Speedway in Southern California (in December 1969), where at least four were killed and hundreds were injured thanks to the Stones' decision to hire the Angels as "security guards." (As a result, he appears in the masterful accompanying film, Gimme Shelter, by Albert and David Maysles.) Numerous years of turmoil and legal complications followed for Barger, not because of Altamont per se, but thanks to an arrest for narcotics possession in 1972 (which landed him in Folsom Prison for four and a half years) and a trial in 1980 for allegations of extensive racketeering. Many associate Barger, however, with his appearances in gonzo journalist Hunter S. Thompson's "inside" account of the Angels: the tome Hell's Angels: The Strange and Terrible Saga of the Outlaw Motorcycle Gangs. As a product of his brief interaction with Thompson, Barger participated in Alex Gibney's documentary Gonzo: The Life and Work of Dr. Hunter S. Thompson. The motorcyclist's resumé includes roles in the AIP biker films Hell's Angels on Wheels (1967, where he is also credited as technical advisor) and Hell's Angels '69 (1969).