See How The Staircase Cast Compares to Their Real-Life Characters

Colin Firth plays Michael Peterson in the HBO Max series The Staircase, which is based on the documentary about the 2001 death of Peterson’s wife, Kathleen.

By Cydney Contreras May 05, 2022 11:00 AMTags
Watch: The Truth Behind Our Obsession With True Crime Stories

Are true-crime fans ready to climb The Staircase once again?

Inspired by the captivating documentary of the same title, the HBO Max series stars Colin Firth as novelist Michael Peterson and Toni Collette as his second wife, Kathleen. In December 2001, Kathleen was found dead at the bottom of a staircase inside the family's home in Durham, North Carolina.

The show explores complex themes like grief and reimagines what Kathleen's life might have looked like in the months before she died.

The story alone is gripping, with all the makings of a John Grisham novel, but the actor's breathtaking performances and dedication to imitating their real-life counterparts add immense depth to the portrayal. Firth sheds his English accent and takes on the boisterous voice of Kathleen's widower, Michael, while Collette goes to unimaginable lengths to depict the dramatic moment Kathleen took her last breath.

The stars are joined in their endeavors by an ensemble cast, who together illustrate the nuance and complexity of the case, which continues to fascinate people to this day. 

photos
2022 TV Premiere Dates

Keep reading to learn about the stars of The Staircase and the real-life people they portray. 

Colin Firth as Michael Peterson

The novelist was accused of murdering his

second wife, Kathleen Peterson, in December 2001. Prior to her death, the couple had been together for more than 10 years, creating a blended family with 5 children between them.

After years of court battles and prison time, Michael—who maintains his innocence to this day—entered an Alford plea to manslaughter in 2017. In an Alford plea, the accused submits a guilty plea in court and acknowledges that the prosecution likely could present evidence that would convict him, but continues to assert his innocence.

Michael released a memoir called Behind the Staircase in 2019. As of 2022, he was 78.

Toni Collette as Kathleen Peterson

The former Nortel executive died in December 2001. Michael found her covered in blood at the bottom of their Chapel Hill home's stairs, sparking a controversial homicide investigation. The case is now considered closed after Michael entered an Alford plea.

Kathleen was 48 at the time of her death. She had one daughter named Caitlin. 

Michael Stuhlbarg as David Rudolf

Hired as Michael's defense attorney in 2001, brash David Rudolf became a central figure in The Staircase's initial episodes, as well as the Netflix sequel released in 2018. He continues to work as a criminal defense lawyer and recently published the book American Injustice about his most famous cases.

Olivia DeJonge as Caitlin Atwater

Although Kathleen's daughter, Caitlin, initially supported her step-father, Michael Peterson, in the days immediately following her mother's death, she later became convinced of his guilt. In 2017, she told Indy Week she remains steadfast in her belief, saying that after the first trial, "I felt confident that I knew what happened. I knew what happened to my mom. While there's no true closure that can ever come for an event like this, for a loss this deep, I was ready to walk away and start moving forward with my life."

Dane DeHaan as Clayton Peterson

Clayton is Michael Peterson's eldest son from his first marriage. One of his dad's biggest supporters, Clayton has long believed that his step-mom Kathleen died in a terrible fall. The 2018 Staircase sequel showed Clayton raising two children with longtime partner Becky. He is now 46.

Patrick Schwarzenegger as Todd Peterson

Todd is Michael's younger son from his first marriage. Like his brother, Clayton, Todd is adamant that his father is innocent. He has since made a career for himself in business and real estate, which he often promotes on his Instagram.

Clayton and Todd's mother and Michael's first wife, Patricia Peterson, died of a massive heart attack in July 2021.

Odessa Young as Martha Ratliff

Following both of her parents'deaths, Michael Peterson and his wife at the time, Patricia, were granted custody of Caitlin and Martha in 1985 and have called him "dad" ever since. She said in the 2018 documentary that she supports her adopted father.

Sophie Turner as Margaret Ratliff

Margaret took an active role in supporting her father's case, even supporting the exhumation of her birth mother's remains to aid in his defense. She remains a steadfast supporter to this day. 

According to IMDb, Margaret has worked in the film and TV industry.

Parker Posey as Freda Black

Black was a lead prosecutor in the first Peterson trial, where she delivered the closing arguments. In 2018, she was found dead from end-stage liver disease due to chronic alcoholism at the age of 57.

Tim Guinee as Bill Peterson

In the documentary, Michael's lawyer brother, Bill, stepped in to offer his brother emotional support and to help with the formation of his legal team.

For more true crime updates on your need-to-know cases, head to Oxygen.com.