Convicted Scott Peterson Breaks 20-Year Silence, Admits 'Terrible Mistake'

Scott Peterson admitted to making a "terrible mistake," but maintained his innocence in relation to the death of his wife, Laci , and their unborn son while speaking publicly for the first time since his 2004 conviction .

Peterson, 49, who is currently serving a life sentence without the possibility of parole at Mule Creek State Prison in Ione, California, claimed he made a "terrible mistake" by having an extramarital affair with massage therapist Amber Frey during the upcoming three-part Peacock docuseries Face to Face with Scott Peterson .

“It’s horrible. I was a total a**hole to be having sex outside our marriage,” Peterson said via PEOPLE .

The former salesman still maintained his innocence in relation to his wife's death, claiming police and prosecutors ignored leads and used circumstantial evidence during the 2004 double murder trial. Laci was reported missing in December 2002 and her body washed up in the San Francisco Bay in April 2003, near where the body of her unborn son was discovered days later.

Two strands of Laci's hair where collected from a pair of pliers found on her husband's boat, which was crucial evidence used in his conviction. Prosecutors claimed that Peterson dumped his wife's body into the San Francisco Bay and used concrete anchors to weigh her down, while he claimed he was fishing on the day of his wife's disappearance.

Prosecutors also painted Peterson as a man who regretted becoming a father and claimed he was motivated to kill his wife in order to avoid paying child support. Peterson never testified during his 2004 trial, a decision he said he regrets.

“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,” Peterson said via PEOPLE .