Here's who is playing who is HBO Max's upcoming limited series "The Staircase," based on the original true-crime docuseries of the same name, directed by Jean-Xavier de Lestrade.
It explores the life of author Michael Peterson, and the suspicious death of his wife, Kathleen.
Colin Firth as Michael Peterson
Colin Firth will play Michael Peterson, who in the early 2000s told authorities that his wife died at their home after falling down the stairs, but a medical examiner determined that she had been bludgeoned to death, turning Michael into a murder suspect. He was convicted in 2003 of murdering Kathleen Peterson and spent eight years in prison.
In 2011, Michael Peterson was granted a new trial, but before it could start, he submitted to an Alford plea to the reduced charge of manslaughter. He was sentenced to time already served and was set free.
Toni Collette as Kathleen Peterson
Collette is playing Kathleen Peterson, Michael Peterson's wife who allegedly fell down the stairs and died -- a medical examiner determined that she had been bludgeoned to death, turning Michael into a murder suspect.
Patrick Schwarzenegger as Todd Peterson
Arnold Schwarzenegger's son is playing Michael Peterson's son, Todd, in the limited series.
Rosemarie DeWitt as Candace Zamperini
Rosemarie DeWitt will star as Candace Zamperini, Kathleen’s sister, who is certain of Michael’s guilt.
Sophie Turner as Margaret Ratliff
The former "Game of Thrones" star will play Margaret Ratliff, one of Peterson's adopted daughters.
Odessa Young as Martha Ratliff
Young will play Martha Ratliff, one of Peterson's adopted daughters.
Parker Posey as Freda Black
Posey will play Freda Black, who prosecuted in Peterson's case. She died in 2019 from liver disease.
Alan Howard/Getty Images
Vincent Vermignon as "The Staircase" director Jean-Xavier de Lestrade
On July 9, it was announced that Vincent Vermignon would star as Jean-Xavier de Lestrade, the director of "The Staircase" documentary.