The family of Sandra Bland interrogates the official narrative of her death in a first-look clip of “Say Her Name: The Life and Death of Sandra Bland,” which HBO published to YouTube yesterday (April 16). 

The documentary, which premieres at the Tribeca Film Festival on April 25, follows the late activist’s mother and sisters as they fight to answer why Bland died in a Waller County, Texas jail cell in 2015. Texas law enforcement officials said that she died from “self-inflicted asphyxiation,” but her family and supporters around the country suspect another explanation. Several key pieces of evidence—most notably, dashboard camera footage that showed ex-state trooper Brian Encinia violently arresting her for a minor traffic violation—emerged in the aftermath, prompting calls for would-be-supporters to “Say Her Name.” 

The clip features Bland’s mother, Geneva Reed-Veal, and sisters Sharon Cooper and Shavon Bland as they discuss viewing surveillance footage from the jail around the time its staffers found Bland. They and family attorney, Cannon Lambert, scrutinize various aspects of the video, which plays over their voices.

“The video that we viewed only went down- it was only for the morning of Monday July 13,” Cooper said. “There’re no time stamps, there’re no dates.” 

Shavon Bland described the video not capturing the cell where her sister was held: “The way they choose to phrase it is, ‘where she was did not have cameras.’ But I would think that that would be strange. Then how are you monitoring your inmates?”

“Why was she in a cell by herself?” Cooper continued. “That’s a big cell for one person.” 

After its Tribeca premiere, “Say Her Name” will debut on HBO at a to-be-determined date later this year.