Attorney Oscar Zeta Acosta established a reputation for confronting power, speaking for Los Angeles’ Latinx peoples and eccentric behavior by the time he disappeared without a trace in 1974. Filmmaker Phillip Rodriguez (“Ruben Salazar: Man in the Middle”) illuminates Acosta’s importance to both the Chicano Movement and counterculture in his latest documentary, “The Rise and Fall of the Brown Buffalo,” which will air on PBS.

A new trailer for the documentary debuted today (February 13). It features archival footage of Los Angeles Police Department (LAPD) officers forcibly dispersing crowds during the height of Chicanx-led activism in the 1960s. A 2012 profile by news outlet KCET noted that Acosta pursued legal and political avenues to systemic change for the city’s Latinx communities. He ran for Los Angeles County Sheriff in 1970 under the Raza Unida Party, campaigning under the promise of disbanding the LAPD. He also defended the East Los Angeles 13, a group of students arrested while protesting a racist school administration system, in court that year. 

Acosta wrote about his legal career and the Chicano Movement in two books, “Autobiography of a Brown Buffalo” and “The Revolt of the Cockroach People.” Those works endeared him to the authors like Hunter S. Thompson, who based the drug-loving Dr. Gonzo of his novel “Fear and Loathing in Las Vegas” on Acosta.

Rodriguez wrote in an emailed statement that the documentary chronicles stories of Acosta’s resistance that have been overshadowed by his excesses. 

“I feel it is a storyteller’s obligation to shine new light on stories, such as Acosta’s, that have been systematically neglected or distorted by mainstream culture,” Rodriguez wrote. “In a society where the Chicano experience is so often reduced to caricature, a sensitive, nuanced rendering of this complex Brown man was long overdue.”

Watch the trailer for “The Rise and Fall of the Brown Buffalo” before the documentary premieres March 23 at 9 p.m. EST on PBS.