While some had feared that this dramatisation would be unnecessary given the comprehensive nature of the documentary, critics are agreed it stands as a powerful companion piece and offers added insight into this extraordinary case.

Read on for everything you need to know about The Staircase cast, including side-by-side comparisons with the real people they are portraying.

Colin Firth plays Michael Peterson

Who is Michael Peterson? Michael Peterson is a novelist and would-be local politician in the city of Durham, North Carolina. One fateful night in December 2001, he called the emergency services to report that his wife, Kathleen, had fallen down the stairs in their home. She died shortly after in what he insisted was a terrible accident, but emergency services still had unanswered questions.

They charged Peterson with murder and a criminal trial took place, where the defendant pleaded ‘not guilty’. He insists that he is innocent to this day. Michael was convicted of murdering Kathleen in 2001 and sentenced to life in prison. However, 14 years later, the charge was reduced to manslaughter and he was sentenced to time already served.

What else has Colin Firth been in? Firth is one of the UK’s most recognised acting talents, earning particular acclaim for his work in period dramas such as A Single Man, The King’s Speech, The English Patient and BBC One’s six-part Pride & Prejudice adaptation. He has also found success in comedic roles with Love, Actually, Mamma Mia! and Bridget Jones’s Diary, while he’s even proven his action chops by taking the lead role in 2014’s Kingsman: The Secret Service and its sequel.

Toni Collette plays Kathleen Peterson

Who is Kathleen Peterson? Kathleen Peterson was Michael’s wife of four years and a successful executive at the now-defunct telecommunications manufacturer Nortel. Their relationship was described by those closest to them as loving and happy, which made the murder accusation against Michael highly surprising. Kathleen had one biological daughter, Caitlin, and acted as an adoptive mother to Michael’s two sons, Clayton and Todd. The couple also were legal guardians to Margaret and Martha, who lost their parents at a young age.

What else has Toni Collette been in? Collette landed on Hollywood’s radar in the mid-’90s following her breakthrough role in comedy-drama Muriel’s Wedding, going on to bag more high-profile gigs including The Sixth Sense, Emma, About a Boy and Little Miss Sunshine. Her most recent projects include acclaimed indie horror flick Hereditary, comedic whodunnit Knives Out and Best Picture nominee Nightmare Alley. On the small screen, she played the lead role on criminally underrated comedy-drama United States of Tara, while she has also led the cast of Netflix miniseries Unbelievable and Pieces of Her.

Michael Stuhlbarg plays David Rudolf

Who is David Rudolf? David is Michael’s lawyer, who represents him in the criminal trial following Kathleen’s death. He is a prominent figure in the documentary The Staircase.

What else has Michael Stuhlbarg been in? Stuhlbarg rose to fame with the one-two punch of the Coen Brothers film A Serious Man and HBO crime drama Boardwalk Empire. Since then, he has appeared in several major awards contenders, including Arrival, Call Me by Your Name and The Shape of Water, as well as Marvel blockbuster Doctor Strange and its 2022 sequel. Last year, he portrayed businessman Richard Sackler in the factual miniseries Dopesick.

Patrick Schwarzenegger plays Todd Peterson

Who is Todd Peterson? Todd is the youngest of Michael’s two sons, but takes on more responsibility than his brother in the immediate aftermath of Kathleen’s death.

What else has Patrick Schwarzenegger been in? Son of Hollywood legend Arnold, Patrick Schwarzenegger has been acting from a young age. His screen credits include Scouts Guide to the Zombie Apocalypse, Netflix’s Moxie and short-lived Fox horror-comedy Scream Queens.

Dane DeHaan plays Clayton Peterson

Who is Clayton Peterson? Clayton is Michael eldest son. He is working to get his life back on track at the time of Kathleen’s death, after serving four years in prison for planting a small pipe bomb in an office at Duke University, where he was studying at the time.

What else has Dane DeHaan been in? DeHaan broke out in the cast of found-footage fantasy movie Chronicle, which led to blockbuster roles in The Amazing Spider-Man 2, A Cure for Wellness, and 2017’s Valerian and the City of a Thousand Planets. On the small screen, he is known for leading the cast of limited series ZeroZeroZero, as well as his supporting role in Apple TV+ drama Lisey’s Story.

Sophie Turner plays Margaret Ratliff

Who is Margaret Ratliff? Margaret is one of two daughters to Elizabeth and George Ratliff, who were friends with Michael Peterson and his first wife when they lived in Germany. When Margaret’s parents died, the Petersons became legal guardians to herself and her sister. Some time later, they moved to Durham, North Carolina.

What else has Sophie Turner been in? Turner is best known for playing Sansa Stark in the HBO fantasy series Game of Thrones, while she also played Marvel character Jean Grey in the two most recent X-Men films (Apocalypse and Dark Phoenix).

Odessa Young plays Martha Ratliff

Who is Martha Ratliff? Martha is Margaret’s sister, who has been cared for by Michael Peterson for most of her adult life. Her late biological mother, Elizabeth Ratliff, would become a major talking point in the trial, as she was also found dead at the bottom of a flight of stairs. Michael claims the circumstances are completely coincidental.

What else has Odessa Young been in? Young has previously starred in the films Assassination Nation, Shirley and Mothering Sunday, as well as the television drama The Stand, which is based on the novel by Stephen King.

Olivia DeJonge plays Caitlin Atwater

Who is Caitlin Atwater? Caitlin is the biological daughter of Kathleen, who soon defects to the prosecution’s side in Michael’s case, after being shocked by the extent of her late mother’s injuries.

What else has Olivia DeJonge been in? DeJonge is an Australian actor, who first rose to prominence in the US after bagging the lead role in M Night Shyamalan’s horror flick The Visit. She went on to play Elle in Netflix‘s young adult thriller The Society, which was renewed for a second season at one stage, but the streamer reversed that decision due to the pandemic.

Rosemarie DeWitt plays Candace Hunt Zamperini

Who is Candace Hunt Zamperini? Candace is the sister of Kathleen Peterson, who firmly believes that Michael is responsible for her death.

What else has Rosemarie DeWitt been in? Interestingly, DeWitt has played the sister of Toni Collette once before in the comedy-drama series United States of Tara. She is also known for roles in Mad Men, Olive Kitteridge and Hulu/Prime Video’s Little Fires Everywhere. On the big screen, she earned acclaim for her performance in 2008 drama Rachel Getting Married, while she also has a supporting role in celebrated musical La La Land.

Parker Posey plays Freda Black

Who is Freda Black? Freda is a prosecutor in the case against Michael Peterson. She died in 2018 of liver disease, around the same time The Staircase documentary saw a surge in popularity from its Netflix release.

What else has Parker Posey been in? Posey started her career primarily in independent film, with projects including Joey Breaker, Dazed and Confused, Party Girl, and Kicking and Screaming. This led to later studio films such as Scream 3, Blade: Trinity and Superman Returns. Most recently, she has played Dr Smith across three seasons of Netflix’s Lost in Space.

Cullen Moss plays Jim Hardin

Who is Jim Hardin? Jim is the lead prosecutor and district attorney during the case of Michael Peterson. He went on to become a judge in the state of North Carolina, but has since retired.

What else has Cullen Moss been in? Moss is known for his recurring role in US teen drama One Tree Hill as well as more recent gigs on Prime Video’s The Underground Railroad and Netflix’s Outer Banks.

Vincent Vermignon plays Jean-Xavier de Lestrade

Who is Jean-Xavier de Lestrade? Jean-Xavier is the director of a documentary series chronicling the case of Michael Peterson, initially aired on French network Canal+ and eventually released on Netflix.

What else has Vincent Vermignon been in? Vermignon is known primarily for French-language work, but did have a guest role in the fifth season of Idris Elba’s acclaimed drama Luther.

Juliette Binoche plays Sophie Brunet

Who is Sophie Brunet? Sophie is the editor working on The Staircase documentary, who becomes fascinated by the case of Michael Peterson and convinced of his innocence. Ultimately, she would fly out to the United States to meet him in person.

What else has Juliette Binoche been in? In addition to numerous projects produced in her native France, Binoche is also known for The Unbearable Lightness of Being, The English Patient, Chocolat and 2014’s Godzilla. She guest starred in an episode of French comedy-drama Call My Agent!.

Tim Guinee plays Bill Peterson

Who is Bill Peterson? Bill is Michael’s brother and a lawyer himself.

What else has Tim Guinee been in? Guinee has appeared in several other major US dramas, including The Good Wife, Homeland, Hell on Wheels and Elementary. Most recently, he played Paul in Netflix drama Inventing Anna. Marvel die-hards may also recognise him from his small role as Major Allen in the first two Iron Man films.

The Staircase premieres on Sky Atlantic and NOW on Thursday 5th May 2022 – sign up for Sky TV here. Check out more of our Drama coverage or visit our TV Guide to see what’s on tonight. 

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