The eight-episode series from Antonio Campos, who directed the Rebecca Hall-fronted feature Christine, and American Crime Story writer Maggie Cohn, explores the life of Michael Peterson (Firth), his sprawling North Carolina family and the suspicious death of his wife, Kathleen (Collette).
DeWitt will play Candace Zamperini, Kathleen Peterson’s sister.
The series is based on the docuseries and various books and reports on the case. Michael Peterson was convicted of murdering Kathleen in 2001, a charge that was reduced to manslaughter in 2017, and Peterson subsequently was released from prison. He had claimed his wife died after falling down the stairs at their home after consuming alcohol and Valium, but an autopsy concluded she died from multiple injuries, including blows to the back of her head with a blunt object.
Jean-Xavier de Lestrade’s docuseries premiered in 2004 and was released on Netflix as a 13-episode series in 2018.
The Staircase is written and executive produced by Campos and Cohn, who also serve as showrunners. The series is a co-production between HBO Max and Annapurna TV.
The casting reunites DeWitt and Collette, who also starred as sisters in Showtime comedy series United States of Tara. DeWitt most recently was seen in Hulu’s Little Fires Everywhere, starring alongside Kerry Washington and Reese Witherspoon. On the film side, she most recently starred opposite Johnny Depp in The Professor and had lead roles in Arizona and Song of Back and Neck. She’s also one of the lead voices in AMC’s upcoming hourlong animated drama series Pantheon. DeWitt is repped by MGMT Entertainment and ICM Partners.