Minneapolis native Erin Lee Carr has done documentaries on Stormy Daniels, the USA Gymnastics scandal, the Bling Ring and Britney Spears. But throughout her highly productive nine years as a director and producer, she had been looking for an excuse to come home. She finally found it.

"I Am Not a Monster: The Lois Riess Murders," premiering at 8 p.m. Oct. 15 and 16 on HBO, humanizes the bizarre tale of Riess, a gambling addict who killed her husband in Blooming Prairie, about 90 miles south of the Twin Cities. She then escaped to Florida, where she killed a woman in a hotel room and assumed her identity.

The search for the "Killer Grandma" made national headlines in 2018 and continues to resonate in the Minnesota town, where Carr spent nearly two weeks getting to know some of its 2,000 residents. The two-part film also includes the first interview with Riess, who is serving a life sentence in a state correctional facility in Shakopee.

Carr's fascination with justice and dogged approach to her work is a family tradition. Her dad, David Carr, was the editor of the now-defunct Twin Cities Reader, an alternative weekly that specialized in investigative reporting. He later reached national prominence with his work at the New York Times and openness about a drug addiction in the bestselling book, "The Night of the Gun."

Carr talked about her dad, who died in 2015, and her latest project during a Zoom interview earlier this month from L.A.'s Universal Studios lot, where she is working on a scripted series about South Carolina's Murdaugh murders.

Q: How did you end up picking this story as a project?

A: My dad was a Minnesota boy through and through. One of the things I kept hearing from him was, "When are you going to do Minnesota? When are you going to do a film about real folks?" So I've been dying to do a story there. I love Minnesota. I think it's so cinematic. When I found Lois' story involved gambling, mental health and murder, I knew it would be interesting. It's all the things I'm interested in.

Q: Did you know when you started that she would agree to an interview?

A: Absolutely not. I originally reached out and got no response. Then no response. No response. Then I was able to get in touch with a family member and we started a really slow relationship-building process. It was really late in the game when Lois said yes. We had been doing phone calls, but the big question was whether I would be able to get into the prison. I put my odds at getting a camera in at 5 percent. A lot of prisons are not camera-friendly, for obvious reasons. When we did get in, that was a big day in my life.

Q: What were your impressions of her when you met her face to face?

A: She was so frantically stressed out. Cameras can be intense and scary. And we had limited time, so we had to go quickly. Normally, I would have let her come to certain things on her own, but I had to be really targeted. Unfortunately, the day we did the interview was the anniversary of the death of someone in her family. That just added to the anxiety.

Q: So how do you work under those circumstances?

A: When I was growing up, I listened to almost every Terry Gross interview that existed. As an adult, I diagrammed them so I could see where she goes for the jugular. When does she ask the really emotional question? I also grew up around my dad, who was a famous interviewer. I think of it as a mental chess match. It's about moving the pieces around with a combination of natural instincts and tons and tons of research. I do a decision tree. "OK, if she's really, really upset, I'll go this way." I once interviewed Peter Madsen, the psychopath who beheaded a journalist on a submarine. You've got to take it seriously because if you miss an opportunity, there won't be another one. It's really high-stakes poker.

Q: Do you have any desire to tackle something lighter?

A: In my life, I'm happy. I'm in great relationships, love my nephew, love my dog. But I'm a really dark person. I'm in the writers room today for this Murdaugh project and I threw out an idea that was so disturbing that someone said, "It's 10 a.m. Please give me a moment to wake up and have my coffee before you start talking about that."

Q: Ron Howard is one of this film's executive producers. How involved was he?

A: Sara Bernstein, who works with Ron, was my main connection. But Ron sees everything and gives feedback. I did run into him at the elevator and told him that I had just watched his "MasterClass." He said, "Was it any good?" I also mentioned that I always wear a baseball cap because of him.

Q: I assume he wears one because of a receding hairline. Why do you like them?

A: I think it's what a director should wear. I have about 40 different baseball caps. I have one I was going to wear for this interview, but I didn't think it was appropriate because it says, "I Don't Want To." This is still a business where there's gender inequality. If I'm wearing one on set, no one is going to mistake me for a makeup person. I'll look like a director or a teenage boy. Whatever.

Q: What do you do to unwind?

A: I've become obsessed with men's tennis. It's like a metronome, back and forth, that I can watch for two to five hours. It's a way to turn my brain off — but I don't really turn it off. There are constant lists in my head. I'm working on five different things at a time. It's increasingly difficult to separate work from my personal life. But I guess there's a time where that's OK and I'm at that juncture. I also love listening to the podcast "I Will Teach You to Be Rich." It's basically couples arguing about money.

Q: That sounds more depressing than talking to murderers.

A: Yeah, right. Conflict is my escapism.

Correction: A previous version of this story misidentified the state where the Murdaugh murders happened. The state was South Carolina.