The Staircase introduced plenty of twists and turns in its first three episodes, but the saga is just beginning as the case against Michael Peterson (Colin Firth) proceeds in the latest installment, “Common Sense.”

Among those who are eager to see the accused killer behind bars is prosecutor Freda Black (Parker Posey) as she attempts to find anything damning enough to put him away. As viewers will recall in the third installment, as Freda and Jim Hardin (Cullen Moss) built their case against Michael, some interesting details came to light.

It turns out that the mother of Margaret (Sophie Turner) and Martha (Odessa Young) Ratliff was found dead at the bottom of a staircase, presumably from an aneurysm, but doubts force the prosecutors to push for an exhumation of the Ratliff girls’ mom. As the incident eerily echoes Kathleen Peterson’s (Toni Collette) untimely demise, it could be the smoking gun that they need heading into the trial. Below, Posey previews courtroom dynamics between Freda, Michael, and his defense lawyer David Rudolph (Michael Stuhlbarg) among other things.

The Staircase Parker Posey and Cullen Moss

(Credit: HBO Max)

What brought you to The Staircase and the role of Freda Black?

Parker Posey: I met Antonio Campos at the Deauville Film Festival. I didn’t have a chance to see his movie there, but I ended up seeing it in New York. He invited me to a screening. So it was just really nice to connect with an independent filmmaker. We became friends, and I saw him a few years after, and he told me that he’d been approached to make a movie version of The Staircase. I don’t know if it was before or after his movie, Christine, but I love his vision and how he looks at America through the lens of a real deal auteur. He knows where to put his camera. He knows what he wants. He was so specific.

I could have done the movie version of The Staircase 13 years ago, but I did the series now. And it’s so much more. It’s such a better story. How could you not do this as a series? I got to do the research and read the books. Antonio and I had a few Zoom meetings. And then we read the scripts on Zoom as a cast last May. And as soon as Colin Firth came on and sounded just like Michael Peterson, [I was] like, “Okay. How much do I have to do? How much do I have to sound like her?”

And [Antonio would] always just say, “We’re not looking for direct. You don’t have to do too much.” I felt like I had to, since she’s so iconic to that case, that I was just fueled by wanting to play such a dynamic, strong, wild, bold woman. I watched all of Court TV, and I connected with her friend, Candy, who worked at the DA’s office with her back then to get close to her that way.

The Staircase Parker Posey and Cullen Moss

(Credit: HBO Max)

It is an uncanny portrayal. Between you portraying Freda Black and Michael Stuhlbarg playing David Rudolph and Colin Firth playing Michael Peterson. You all nail these roles so well.

It’s so fun to be able to grab hold to a part by looking at another real person. I’ve never done that, so that was fun.

What kind of experience is it to walk into the courtroom and recreate moments that so many true-crime enthusiasts have come to know over the years following Michael Peterson’s real-life case?

It was a moment when we all first really saw each other as a group. And having watched the case, looking over and seeing the daughters, and the sons, and Michael, and David and then our team. It felt like theater. I remember my closing. I had watched all of Freda’s closing argument, which is almost an hour. She’s so theatrical. She’s really playing the bigotry card. She knows her audience. She was very aware of her effect. She knew the power of that persona, and she played it.

Candy was like, “Freda wasn’t like that.” She had low self-esteem outside the courtroom, but in the courtroom, that was her domain. That was her. That’s what she was really gifted at. But she also played piano at church and sang. One of the things I loved about playing her was working with my co-star Cullen Moss. We had such a good time and talked to Jim Hardin together, and to Candy, Freda’s friend, together and became really good friends. It did feel competitive when I had to get up and walk around [in the courtroom] because I probably worked 10 days on the show, total, over six months.

The Staircase Parker Posey and Cullen Moss

(Credit: HBO Max)

That’s incredible. It doesn’t feel that way watching. That’s amazing. 10 days?

Yeah. We were working really hard. When I was doing my closing arguments, I remember looking over at Michael Stuhlbarg, who was sitting back in his chair, and he just gave me two thumbs up. And it meant so much to me. He knew I had to be strong. That moment, it was just really nice, because sometimes you get a little shy. It’s like going in and jumping off the diving board. You just don’t know if it’s all going to land once the performance is in the air and on the screen. And being able to watch him and everyone else… They came through the door like we were in the documentary. It was eerie at times how uncanny it’d start to feel, because we were all obsessed with the case.

Michael giving you the thumbs up is so sweet. Both of your characters have a case to make. What was it like getting to go toe-to-toe with him in the courtroom?

I’ve been a fan of his forever. He is just a real actor’s actor. He’s always so interesting to watch. And so, he got to talk to the real David Rudolph, and then I wanted to talk to him too. So I got his information from Michael Stuhlbarg. When we talked to Jim Hardin, what struck me about playing a prosecutor and about this world is just how much it takes out of your life. Everyone is in this really dark space, the prosecutors and Freda envisioning a man who would easily do this to his wife who he loved. What does txhat look like? [There’s also] this thing about playing a Southerner. There’s a sweetness, but also this brutality. There’s something that’s warm and sentimental and something that’s very dramatic.

'The Staircase': Michael Stuhlbarg on Becoming 'Logical' Lawyer David RudolfSee Also

'The Staircase': Michael Stuhlbarg on Becoming 'Logical' Lawyer David Rudolf

Colin Firth plays his client, accused killer Michael Peterson, in the HBO Max drama.

In your respect, which person had the tougher case to argue? Was it Freda or David? They both have these big hurdles to overcome and it doesn’t feel as though there’s ever one clear path towards victory in this story.

Oh yeah, I totally agree. That’s what’s so interesting about the story. It branches out in its own way and becomes its own form. I don’t really look at it like who had the harder part, so much as look at how this real-life story has taken shape. There’s an owl!

There is an owl theory.

Candy, when I talked to her, she was like, “Well, what I always thought, because Kathleen had all these nutcrackers going down her stairs, I think it’s the nutcracker. I think he did it with the nutcracker, but that’s just me.” And so there’s so much back and forth and head-scratching. It’s exhausting.

The Staircase, New Episodes, Thursdays, HBO Max

More Headlines:

Originally published on tvinsider.com, part of the TownNews Content Exchange.