Parker Posey will star alongside Colin Firth, Toni Collette, Juliette Binoche and Rosemarie DeWitt in the HBO Max limited series “The Staircase.”

The eight-parter is based on the docuseries of the same name and various books and reports on the Michael Peterson (Firth) case. Peterson was accused of murdering his wife, Kathleen (Collette), in 2001. He claimed she died after falling down the stairs at their home after consuming alcohol and Valium, but police suspected he bludgeoned her to death and staged the scene to look like an accident. An autopsy revealed that Kathleen died from blows to the back of her head with a blunt object and other injuries. The docuseries was originally released in 2004, with creator Jean-Xavier de Lestrade updating with new information years later. Netflix released it as a 13-episode series in 2018.

Posey will play Freda Black, an assistant district attorney and prosecutor. DeWitt will play Peterson’s sister, Candace Zamperini. Details about Binoche’s character have yet to be revealed.

Posey is represented by Gersh. Posey made her official acting debut in the film “Joey Breaker,” and soon was starring in numerous indie films through the 1990s. She added many television appearances to her resume, including: “Futurama,” “The Simpsons,” “Will & Grace,” “Boston Legal,” “Parks and Recreation,” “The Good Wife,” “Louie,” “Inside Amy Schumer” and “Search Party.” Her most recent starring role on TV was in Netflix’s sci-fi series “Lost in Space.”

Variety exclusively reported that“The Staircase” was in development back in November 2019. It was picked up to series at HBO Max in March. It is written and executive produced by showrunners Antonio Campos (“The Sinner,” “The Punisher”) and Maggie Cohn (“American Crime Story,” “The Black Dahlia”). Campos will also direct six of the eight episodes. The series is a co-production between HBO Max and Annapurna Television