“Dirty John” creator Alexandra Cunningham didn’t want to change the true story of Betty Broderick’s brutal 1989 murder of her ex-husband and his new wife. But her version tells the tale of what led her to that.

The second season of the true crime anthology series, which premiered Tuesday on USA Network, follows Broderick, a quintessential ’80s California housewife and mom who gave up her own life to guide her husband Dan’s career.

“She went from living with their parents to living as someone’s wife,” Amanda Peet, who plays Betty in “Dirty John: The Betty Broderick Story,” said. “She didn’t have any identity outside of that.”

Cunningham, who’s also the showrunner, believes Broderick had little voice in that path.

“Everything was designed to contribute to his success,” she said. “They climbed that mountain together and they made those sacrifices together, and then suddenly they got to the top of the mountain and Dan decided he wanted something else.”

Eventually, Dan Broderick, played by Christian Slater, gets bored, having moved from medicine to law and now pulling in more money than they know what to do with, and finds freedom in his 21-year-old intern, Linda Kolkena.

The series takes Betty down the rabbit hole, from threatening voicemails to driving a car through a house to the infamous murders. But Cunningham seems more interested in exploring the “why” than the “what.”

“I think Alexandra felt like the Betty Broderick story was worth retelling now that we know more about mental illness and about the women who grew up in Betty’s era who sublimated themselves into becoming wives and mothers,” Peet said.

“She wanted to go into a deeper exploration of what makes a suburban housewife snap.”

Cunningham, best known for her work on “Desperate Housewives,” says she views the “Dirty John” franchise as “stories of love gone wrong,” following the first season about middle-aged divorcee Debra Newell and her con man boyfriend-turned-stalker.

“They contain a degree of coercive control, which is something that we’re all just now becoming aware of and talking about,” Cunningham said. “Men who make women feel isolated, call them crazy, limit their access to money. They make them feel like their life could fall apart at any moment.”

Broderick’s story, Cunningham said, was shaped by the time and by a media that presented her as an “angry, crazy woman.” She wanted to tell it from Broderick’s perspective, or as best as she could from research.

The housewife, who turned 42 two days after the murders, was found guilty of two counts of second-degree murder and sentenced to 32 years in prison in 1991. Now 72, she’s currently serving out her time at the California Institution for Women after being denied parole multiple times.

“At any given moment in her story, she’s confused or she’s wrong or she can’t remember,” Cunningham said. “She has a very lethal idea of what fairness is. But this narrative that Betty constructed for herself about everything that happened is why she killed. Whether it was right or wrong, it’s what she thought.”

Cunningham distinctly remembers the real trial and coming home from high school to hear the news. Peet, 48, barely knew the story at all before she signed on to the project. But both believed there was something more.

For Cunningham, “The Betty Broderick Story” is less a tale of madness and murder than one of unfulfilled promises.

“Everyone is yearning to matter to someone,” she said. “We can all relate to wanting to be loved and wanting to trust someone and not wanting to believe that the person we love and trust and who knows us better than anyone is someone who’s hurting us.”