The death of Kathleen Peterson in December 2001 and the subsequent investigation that led to the conviction of her husband, novelist and one-time Durham, North Carolina mayoral candidate Michael Peterson, for her murder is revisited in HBO Max’s The Staircase starring Colin Firth and Toni Collette. Kathleen was found dead in a pool of blood at the foot of a staircase in her Durham home, and the amount of blood plus suspicious wounds on her head led police to believe fool play was involved.

Michael claimed his wife must have fallen while descending the stairs, but in 2003 a jury disagreed. Although he was sentenced to life in prison, Peterson was granted a new trial in 2011 and ultimately entered an Alford plea in 2017. He’s currently a free man and once again calls Durham his home.

If this all sounds incredibly familiar it’s because Kathleen’s death and Michael Peterson’s trial were the focus of the award-winning documentary series The Staircase directed by Jean-Xavier de Lestrade. Peterson has also written two books – Behind the Staircase and Beyond the Staircase – about his life following Kathleen’s death.

During the Television Critics Association’s winter press tour The Staircase writer, executive producer, and co-showrunner Antonio Campos explained this HBO Max limited series is not just dramatizations or recreations of scenes from the documentary.

“We were very interested in what happened leading up to the night of her death and then sort of from there after the documentary was over. And a lot of it was what was going on when the cameras were off,” said Campos. “So, we were going off of a lot of different sources. The documentary is just one source. It’s kind of where the journey started for us but wasn’t the only thing we’re referring to.”

Campos and writer, executive producer, and co-showrunner Maggie Cohn’s research included Diane Fanning’s book Written in Blood as well as numerous articles about the trial and investigation. They also conducted interviews in order to tell Kathleen and Michael’s stories.

“We took cues from what we knew and created scenes based on that. One of the approaches that I think every actor took and that we took in every aspect of the show, including the writing and then wardrobe and hair and makeup, was we don’t want to just replicate things. We wanted to find things where we – the storytellers – and reality kind of met,” explained Cohn. “We didn’t want any actor to be forced to just be whatever characteristic they were playing, whatever person they were playing. We wanted to find where does that person and that actor meet and where do we find this sort of beautiful combination of the two? And that’s really the approach. So, we were really not trying to recreate a dramatized thing that you’ve seen. We really wanted to create a whole new story.”

Michael Peterson was convicted of murder, however, Colin Firth tried not to judge him as he took on the role.

“It’s something that was ingrained into all of us as students, but it’s just not your job. As a person you can walk away afterward and judge all you like, if that’s what you want to do or that’s what your instincts are,” explained Firth. “It’s a subjective job. And what’s interesting about the approach here is it, I think, deftly avoids taking up a single position. It’s the nature of the exercise here is to keep doubt alive, to mess with your expectations, to tease you with a potential resolution into thinking perhaps you now can find some certainty, and then it subverts that constantly. And I was kind of steered around because of that.”

Firth continued: “It wouldn’t have been possible and it certainly would have defeated the purpose of the exercise if I did take up a single position and impose my judgment because then I wouldn’t have been free to explore an alternative interpretation. And it does play with different interpretations. So, the whole business about not judging your character but justifying your characters isn’t a moral one. It’s stagecraft. It’s a creative necessity, really. You have to stay as open as possible just for the purpose of the exercise.”

Colin Firth described playing Michael Peterson as a unique experience in that it was difficult to construct a biography of a person who is so hard to understand. He used the documentary, including outtakes, and Peterson’s own writing to try and figure out who this man is and how to approach playing him in The Staircase.

“…I was less interested in finding a way to mimic anything or assimilate his mannerisms for the sake of it. It’s just I was looking for codes. I was wondering what you can find out about a person by the way they speak, by the way they phrase things, by means of body language and that sort of thing,” said Firth. “It’s kind of just exploring what I had, which were his words and his way of delivering them. The job of an actor is entirely that. Someone else has written it. How a thing is said can be mightily eloquent, really. So that was really my first point of contact was all of that.”

During the TCA panel Firth was asked about the challenges of telling a story that’s already been told in other forms.

“One of the only things I can think of where we almost used verbatim was Michael Peterson taking the documentary crew on a little tour of what happened and his account of that night and going out to the pool. And that is something we’ve seen in the documentary. It was very interesting to me; it was one of the few occasions where in a way the requirement was to reproduce it and fairly closely approximate to what you’d seen.

But what you don’t see in the documentary is the documentary crew following him. And if you’re telling a story, particularly if it’s the first moment you’ve ever been interviewed, if you’re telling a story and you’ve got a camera on you and a boom mic and all the rest of it, you’ll get a different perspective on what was going on while he was telling that story. It’s very unadorned.

We weren’t sort of trying to point to anything or create an interpretation out of it. I certainly wasn’t. It’s just saying, ‘Well, we see it from that lens quite literally, and now we’re going to see it from another perspective where the picture isn’t a man alone, it’s a man surrounded by people who are recording him and watching him.’

And so, I think that […] it’s actually making use of the familiarity with the story. This is addressing that. It’s actually the fact that you think you know certain things, the fact that you’re familiar with certain things is kind of the point here. This isn’t telling the story for the first time. It’s looking back on the way it’s already been told and seeing if we can play with the perspectives,” said Firth.

Campos has been following this case for a long time and noted it’s had several different endings over the years.

“When I started there was one end to the story, which was Michael was serving life in prison. And then it just kept changing. Then Michael was out and then eventually Michael took a plea. And so, while it feels like this story has kind of been told before, the reality is, is there’s so much of the story that hasn’t been explored, particularly who was Kathleen Peterson,” said Campos. “We don’t get to know Kathleen Peterson except as sort of a photo, a blurry image in videos. And we only get to know Michael Peterson through footage in a documentary where he knows there’s a camera on him. And we experienced the family that way too.”

Campos added: “What we were interested in was we just saw a family drama more than a crime show. And exploring the events leading up to that night and after that night, in some way, felt like we were getting closer to something like the truth than sort of staring at a bunch of evidence and going over a lot of the things that people get obsessed about with this case, whether it be the blood-stain pattern or the shape of the lacerations and things like that.”

And speaking of lacerations, Campos confirmed The Staircase will address the owl theory. “We took it as seriously as any other theory,” said Campos.

Michael Peterson hasn’t shied away from interviews and continues to discuss Kathleen’s death as well as his time in prison. However, Colin Firth chose not to speak with him, or any member of the Peterson family, while working on The Staircase.

“I felt that the way that the script was structured, just the whole approach of this was its own ecosystem, so to speak. And I think that these are created characters. I mean, we all know what the source is. We all know that these characters have names of living people, but it’s very carefully calibrated to tell the story in a certain way and I felt that I wanted to keep my inspiration, my motivation, and the sense of the source material as much as possible contained within the script and the way it was written,” explained Firth.

“I felt that that could have been skewed in some way if I had personal connections during the shooting of this with Michael Peterson or the people concerned. If I’d had a personal response to the meeting, it might have prevented me from tuning in to this world of varying possibilities that had been created. So, I wanted to be as open to the possibilities of the script as possible, and I don’t think I wanted it to become too specific due to anything outside that frame.”

The Staircase limited series premieres on HBO Max on Thursday, May 5, 2022 with the release of the first three episodes. Colin Firth and Toni Collette lead a cast that includes Michael Stuhlbarg, Juliette Binoche, Dane DeHaan, Olivia DeJonge, Rosemarie DeWitt, Tim Guinee, Patrick Schwarzenegger, Sophie Turner, Vincent Vermignon, Odessa Young, and Parker Posey.