Hunter S. Thompson and Oscar Zeta Acosta

Oscar Zeta Acosta was a lawyer, an author and a counterculture icon who counted Hunter S. Thompson as a close friend. His powerful literary voice made him a revered figure in the Chicano Movement of the 1960s and ’70s and a scourge of the white supremacy and status quo of the time. Yet few know who he was.

His story is told in the documentary “The Rise and Fall of the Brown Buffalo,” premiering Friday, March 23, on PBS (check local listings). Using archival footage and images and dramatized portrayals of Acosta, Thompson and other key figures of the era, the hourlong film paints a portrait of a larger-than-life character with extraordinary appetites for drugs and drink, and an activist who exposed racial bias, hypocrisy and repression in the California justice system and served as the inspiration for Dr. Gonzo in Thompson’s iconic novel “Fear and Loathing in Las Vegas” before mysteriously disappearing off the Mexican coast in 1974.

“Oscar was a hungry man, a man out of time, a man that was not really born of this time, not appreciated in the moment …,” explains Phillip Rodriguez, the film’s director. “Like so many minority characters in American history, they are shuffled off to the side. In this case he was the Queequeg, the noble savage, or ignoble savage in this case, relegated to an asterisk in the dustbin of history.”

Born in Texas and raised in Mexico and Central California, Acosta earned his law degree from the San Francisco Law School in 1966 and went to work as an antipoverty attorney in East Oakland before joining the Chicano Movement in East Los Angeles in 1967, defending Chicano groups and activists. His work there drew the attention of Thompson, who wrote an article about him for Rolling Stone magazine. A personal and professional relationship developed, though one that Acosta – the self-proclaimed “Brown Buffalo” of the film’s title – wasn’t completely comfortable with.