The finale of “The People v. O.J. Simpson” might not have included any big surprises when it came to the verdict itself, but it did offer one revelation about Marcia Clark.

Sitting in her office with Chris Darden (Sterling K. Brown) after the verdict, Clark (Sarah Paulson) confides to her colleague that she was raped as a teenager — and that that experience motivates her as a prosecutor.

“When I had my first rape case, what happened to me of course came flying out from whatever rock I’d jammed it under, and I had to deal with it,” says Paulson-as-Clark in the show. “It was hell all over again in a way, but it made something very, very clear to me. I had something, this thing in me that wanted vengeance, vengeance for victims. That’s what justice is to me.”

Including that scene was “very important to Sarah (Paulson),” executive producer Scott Alexander tells Variety. “It was giving her a mission statement in her last scene with Chris. It was both of them leaving their professions, but it was one last insight into what drove Marcia Clark. The fact that the perpetrator got away on that case and she felt the perpetrator got away in this case. It felt like it tied it all together.”

Paulson explains to Variety that she learned about the rape from reading the prosecutor’s book, as part of the research she’d done to prepare for the role. “I didn’t think any context was needed to explain to viewers or the world as to why she was the way she was,” she says. “What she was doing was trying to put a man she believed to be guilty behind bars for a murder she believed he committed. However, her personal history explains some of why she was unwilling to play the lawyer game the dream team was playing. Johnnie Cochran brought his big personality to the trial and he used it to his advantage. (But) Marcia was incapable of doing that kind of thing.”

For Paulson, Clark’s personal history was a way of contextualizing the choice to let the facts speak for themselves. “There’s a deeper connection that she had to being a woman who had been abused, who had been literally raped,” she says. “She talks in her book, too, about her first husband following her around a little bit and feeling overly watched by him. So she had connective tissue to cases in her life where things like this came up.”

Keeping the secret took its toll on Clark, says Paulson. “She had to take to her bed one day and she couldn’t figure out what was going on,” she says. “And what was going on was (the trial) brought back all of these feelings and all of these memories that she didn’t talk about publicly until she wrote her book. People didn’t know. Darden didn’t know. Nobody at her work knew. She chose personal privacy, almost to her own detriment. She didn’t process anything that happened to her until so much later.”

Paulson met Clark for dinner halfway through the series, and has stayed in touch with her since. She says the lawyer-turned-author appreciates that the show has put the gender discrimination issues front-and-center. “The way Marcia was treated publicly was never something that was brought up, even by women — not the female journalists, female lawyers, other prosecutors,” says Paulson. “It was very strange, the abandoning of Marcia Clark. That’s something I’ll always scratch my head at. So I think she feels really pleased that (executive producer) Ryan (Murphy)  made that so strong a part of the narrative.”