How ‘The Staircase’ Brings Kathleen Peterson’s Story to Life

The Museum of Modern Art in New York City transformed into a red carpet on Tuesday night for the premiere of The Staircase, starring Colin Firth and Toni Collette.

The upcoming HBO Max series is based on the true story of novelist Michael Peterson (Firth), his sprawling North Carolina family and the suspicious death of his wife, Kathleen Peterson (Collette), after she is found dead at the bottom of a staircase in their home.

Jean-Xavier de Lestrade’s docuseries by the same name chronicled the case against Peterson, who was accused of killing his wife in 2001, and aired on Sundance Channel in 2005. The making of the docuseries is included in HBO’s The Staircase, with Vincent Vermignon playing de Lestrade.

Vermignon says he was able to spend time with the French filmmaker leading up to production on the series, which helped him prepare to take on the role. He also spoke with director Antonio Campos about finding a balance in playing a real person in a fictionalized story.

Being a part of HBO’s take on the story helped Vermignon get better insight into who Kathleen was, since the original docuseries was made after her death.

“It helped me to understand what was the dynamic,” he said. “If you ask me if Michael Peterson did it or not, I can’t tell you. I’m even more confused than before. But right now, I feel more like the victim was Kathleen Peterson, and I understand the fantastic woman she was.”

Rosemarie DeWitt, who plays Kathleen’s sister Candace, echoes that sentiment and was excited to be a part of bringing Kathleen’s story to life. She was also drawn to the role of Candace because she felt that her character was villainized in the original docuseries, and she wanted to change that.

“I wanted to take a crack at bringing some more humanity to her so that people could understand why she was fighting so hard,” DeWitt told The Hollywood Reporter. “For the people that do watch it, I hope that they can turn a more sympathetic gaze toward her because she was really a victim in this story, and I felt like she was used to be villain.”

The Staircase explores the question of whether or not Michael Peterson killed his wife and complicates the answer many people, including the cast, thought they knew.

“I mean, I was sure he did it,” said Justice Leak, who takes on the role of Tom Maher, a lawyer on Michael’s defense team. “I was sure he did it when I first started, but then as we film and as we go, and you start to see how complex and complicated all of our individual stories are, and if you look at it from someone else’s perspective, it can easily look guilty or innocent depending on where you’re coming from.”

Leak added that one of the interesting things about the series is that it reflects what the American justice system looks like today and how every aspect of a case plays out on the world stage.

“It’s really about, in the American justice system, who does tell the best story, and we’re seeing that more than ever in our world today,” he said.

Several of the cast members were able to consult their real-life counterparts before filming and had seen the docuseries multiple times, which helped them do their individual roles justice. It also helped that Campos and his co-showrunner Maggie Cohn had “a plethora of knowledge about the pace [of the story], about the different individuals, about the family, what the relationship was to each other,” Patrick Schwarzenegger, who plays Todd Peterson, said.

Campos first saw the original docuseries in 2008 and had been interested in the story ever since. He thought it was interesting that the French filmmakers were embedded in the Peterson family’s lives, and he felt there was an angle into the story through them.

“And [with] a character at his center that is as mysterious as the mystery itself, it just felt like something that I hadn’t seen,” Campos explained. “It felt like something that if I kept following, it’s just would get more and more interesting, which it did.”

The writer-director said he hopes that if viewers go into The Staircase with the question of whether or not Michael killed Kathleen, they come out with something deeper.

“At the very end of the day, even if I have a feeling about what happened, what I’m really OK with now is the gray, and hopefully everyone is OK with the gray at the end of this.”

The Staircase premieres on HBO Max on May 5.