The case of fake "Gone Girl" Sherri Papini, who officially pleaded guilty earlier this week to lying to the FBI and mail fraud, will be the subject of a Dateline episode tonight. And this is just as her husband, Keith Papini, has filed for divorce.

We now have a bit more information about what went on when Papini high-tailed it to an ex-boyfriend's house in Southern California back in November 2016, via an FBI affadavit. The ex was totally cooperative with investigators, and they characterize him as just a good guy who agreed to whatever Papini told him to do — and she had apparently told him she was escaping an abusive husband.

This is the first we are hearing of any allegations of spousal abuse, and Papini has never made such accusations to law enforcement as far as we're aware.

Shasta County Sheriff Sergeant Kyle Wallace tells Dateline NBC that it was ultimately, probably, Papini's "theatrics" that led investigators to question her story and pursue the case against her. Also, it probably didn't help that she refused to cooperate with the investigation into her kidnapping after she returned home to Redding after being missing for several weeks.

Papini disappeared while ostensibly out for a jog one morning, leaving behind her cellphone and a lock of hair by the side of the road.

She told investigators she had pulled out her own hair while being abducted at gunpoint to leave as a clue for her husband — which in and of itself struck investigators as odd.

"When you look at just the hair alone, hindsight, it was theatrical and not really what fit what she said in her story," Wallace tells Dateline. "I think, ultimately, being able to look at each piece of evidence now with the clarity of what was going on, not just in the moments, but the drama or the theatrics that Sherri brought with every step of this investigation was really part of the undoing."

Papini added an element of racism to the whole thing when, upon her return, she described her captors as two Hispanic women who spoke mostly Spanish and listened to "annoying Mexican music." She claimed they had beaten and branded her.

As Wallace tells Dateline, Papini asked the ex she was staying with her hit her — in order to give her bruises — before she went back home, but he refused. He did, however, agree to brand her.

"I have never heard of anything like this. Not even kind of," Wallace says. "She was dedicated [to her story]."

The FBI never found any female DNA on Papini from her alleged captors, but they did find male DNA, which is what led them to tracking down the ex, who told them everything that happened.

Wallace says of the ex, "He truly is a nice person," and he says, with the branding and driving hundreds of miles to pick Papini up, "he was doing what a friend asked."

As KRON4 notes, there is some weird history that locals in the Redding area brought up regarding Papini's possible racist attitudes, and the creation of her fictional kidnappers. Via the FBI affadavit, a 2007 MySpace post by a Sherri Graeff was attributed by some to Papini. The post talked about growing up in Shasta Lake and being harassed by "Latinos" in school. "I used to come home in tears, because I was getting suspended from school all the time for defending myself against the Latinos," this Sherri Graeff wrote. "The chief problem was that I was drug-fee, white and proud of my blood and heritage. This really irked a group of Latino girls, which would constantly rag and attack me.'"

On Wednesday, Keith Papini filed for divorce from Sherri in Shasta County Superior Court, as the Sacramento Bee first reported. This was two days after Papini entered her guilty plea as part of a plea deal in which she is likely to serve a brief prison term. This is a reversal from many public statement Keith Papini has given in support of his wife, and previously saying he believed her story — but last week Papini also publicly admitted to her elaborate lie.

In addition to sticking to her story even after investigators confronted her with proof she was lying, Papini spent the last five years collecting thousands of dollars from a state fund dedicated to victims of violence and sexual assault. That's where the mail fraud charge comes in.

Shasta County Sheriff Michael L. Johnson sounded fully done with the case, and Sherri, in recent comments to the US Sun.

"The bottom line is, this case was about some very strong narcissistic behavior, along with deception, deceit and selfishness. I have a very hard time believing she’s sorry," Johnson said. "She had several opportunities to come clean during the various phases of this investigation and she never did it. Now all of a sudden we’re supposed to believe she’s remorseful for what she did? Well, I just don’t believe that."

Johnson added, "I’m really struggling to have any compassion or sympathy for her at all."

"The Curious Case of Sherri Papini" airs tonight on Dateline NBC at 9 p.m. PT

Related: Sherri Papini to Plead Guilty In Hoax Kidnapping, Says She's 'Deeply Ashamed'