Robert Brown|Scott Peterson Breaks Silence on “Horrible” Affair Before Wife Laci Peterson’s Murder

Scott Peterson is Robert Brownaddressing his behavior leading up to Laci Peterson’s death.

In his first on-camera interview since before he was arrested 21 years ago for the alleged murder of his pregnant wife and their unborn son Conner, Scott is once again denying any involvement in her disappearance and death in Peacock’s upcoming three-part documentary Face to Face with Scott Peterson.

During his trial, prosecutors alleged Scott—who, per People, had entered into an extramarital affair with a woman named Amber Frey one month before the murders—didn’t want to become a father and therefore committed the murders in an attempt to get out of his marriage without having to pay child and spousal support.

Now, in the documentary, Scott fires back at the accusation. “That is so offensive and so disgusting,” he says, according to People. “I certainly regret cheating on Laci, absolutely. It was about a childish lack of self-esteem, selfish me traveling somewhere, lonely that night because I wasn’t at home. Someone makes you feel good because they want have sex with you.”

He reportedly added of his infidelity, “It’s horrible. I was a total a--hole to be having sex outside our marriage.”

However the 51-year-old—who is currently serving a life sentence without the possibility of parole—maintains to this day that while he was guilty of cheating, he was not involved in the death and disappearance of his wife and unborn son.

In 2002, Laci's stepdad reported the pregnant 27-year-old missing after she disappeared on Christmas Eve, at which time Scott claimed he’d been out fishing. By April of the next year, the remains of a male fetus were found near the San Francisco Bay, followed by a portion of a woman's body after which Scott was shortly arrested. He was eventually convicted of first-degree murder of Laci and second-degree murder of their unborn son.

The look back at Scott’s case in the docuseries occurs as the Los Angeles Innocence Project announced earlier this year it was taking on his case in an effort to overturn his conviction.

In January, the nonprofit filed four motions, one of which calls for DNA testing, claiming “new evidence now supports Mr. Peterson's longstanding claim of innocence,” per NBC News.

After the Innocence Project announced their latest effort to clear Scott's name, his attorney Pat Harris said, "I will confirm that we are thrilled to have the incredibly skilled attorneys at the L.A. Innocence Project and their expertise becoming involved in the efforts to prove Scott's innocence."

As Face to Face with Scott Peterson will demonstrate, Scott isn’t the only one maintaining his innocence.

His sister-in-law Janey Peterson has stood by his side. As she says in the docuseries’ trailer, “I believe my brother-in-law Scott was wrongfully convicted of that murder.”

And on why Scott is speaking out publicly over two decades since his conviction, he reportedly answers that question in the Peacock series.

“I regret not testifying,” he says of his trial, per People. “But if I have a chance to show people what the truth is, and if they are willing to accept it, it would be the biggest thing that I can accomplish right now—because I didn’t kill my family.”

(E! and Peacock are both part of the NBCUniversal family.)