The Mind Of Scott Peterson

Scott Peterson's public statements could play a major role in his murder trial. Will his own words help or hurt him? Correspondent Peter Van Sant reports.

A month after his wife Laci's disappearance, a private Scott Peterson went public.

He granted four television interviews, with the hope of taking the suspicion off him, and putting the focus back on finding Laci. Was he a desperate man in search of his missing wife, or a cheating husband who became a cold-blooded killer?

Either way, Peterson's own words may now be coming back to haunt him. Despite strong objections by his defense attorneys, the jury is about to see those interviews. Prosecutors plan to use the tapes to prove Peterson repeatedly lied.

One of the journalists who interviewed Peterson in January 2003, Gloria Gomez, recalls: "He seemed to be very scripted. Very media savvy."

Nick Flint, a former investigator and polygraph examiner with a California sheriff's department, now teaches other law enforcement officers how to detect deception when interviewing potential suspects. He believes Peterson's media strategy has backfired.

"When he is not telling the truth one of the things he does is he lowers the volume level and he mumbles the words," Flint observes about Peterson.

In an interview with ABC News, Peterson claimed he told police about his affair with Amber Frey as soon as Laci disappeared.

Peterson: "That was the first night we're together, the police, I spent with police."

Diane Sawyer: "You told them about her?"

Peterson: "Yeah from December 24th on..."

What Peterson told Sawyer turned out not to be true. Frey, not Peterson, informed police about their affair.

During an interview with Gomez, Peterson declined to answer some questions.

Peterson: "We're starting to go into areas that investigators have asked me not to comment about. So we should probably simply put the brakes on."

But that was actually not the truth either.

"When I met with detectives and I showed them my tape, Gomez says, "they said 'We never told him not to answer questions. We want to hear what Scott has to say.'"

Forensic psychiatrist Michael Welner has also taken a look at the Peterson interviews. He says, "The most significant aspect of these interviews to the prosecution is not so much as contradictions but the absurdities of some of the statements."

Peterson told ABC: "The first word that comes to mind is glorious. We took care of each other very well."

Welner questions why he would make that statement about his marriage right after talking about his mistress.

Peterson also said: "I'm glad Amber came forward."

Says Welner: "He's glad? No one's going to believe that. That's absurd."

Flint says it goes beyond absurdity. He thinks Peterson is just plain lying. Case in point: when Peterson says he told Laci about the affair with Frey.

Gomez asked Peterson: "Did Laci find out about the affair or did you just come out and tell her?"

Peterson replied: "No I informed her about it. I don't believe she knew."

Gomez: "Why come out? I mean what made you say, 'I'm gonna tell her today.' What made that day the day to tell her?"

Peterson: "Just because it was the right thing to do."

According to Flint, "There should have been some reason, some fine-grained details that would go with that, as to why it came out at that moment in time. So when a person makes up a story, those are things that get missed from the story."

He finds rich details in the moments he thinks Peterson is being truthful.

Gomez asked Peterson: "The life insurance policy. Why take one out on Laci? $250,000?"

Peterson said: "We have life insurance policies in place that were established when we bought this home you're in right now, two years ago."

"See all the collateral data that's going with the answer about life insurance?" Flint asks. "That's the truth. There's more detail about the life insurance policy than there is about a very important conversation that he had."

It's not just Peterson's words, but also his actions that Gomez found interesting. In the course of their interview, Peterson's cell phone rang. He kept talking over the ring, before finally getting up to hunt for it. After a search, he found it in the kitchen and shut it off.

Says Gomez, "When you look at the tape you realize he didn't hesitate to turn it off. And some would say if you're a concerned husband, if your wife is missing...you know, you would have that cell phone clinging to you. Every call is an urgent call. No matter when it happens."

In Welner's opinion, it was a mistake for Peterson to grant the interviews. "The focus of the interviews became more of how unbelievable he was and how detached he was, rather than the substance of what he said," he says.

Peterson's nervousness at being a suspect could have caused him to give misleading answers, according to Welner. "We don't know what it's like to have our fate, our life, hanging on every word," he says. "He comes into these interviews knowing that he's under suspicion. Knowing that he may be under arrest. And this isn't just his wife's disappearance. This is a potential death penalty case."

Although the case against Peterson is largely circumstantial, Welner believes some of the discrepancies on the tapes may have irreparably damaged his credibility.

He asks, "At some point when does a jury just say, 'enough'? He lied because he did it."