Transcript for Amber Frey tells police about her relationship with Scott Peterson: Part 5
I've never been able to fully understand why Laci's disappearance and murder captivated so many people, but I have my own theory. I believe that Laci wasn't going to allow Scott to get away with murder, so she kept the spotlight shining down on him until he was convicted. Earlier this week, the Modesto police department was made aware of an article that was to appear in "The national enquirer" revealing new information regarding Laci's case. Out of respect for the family, the police department felt they should provide the information to them directly so they wouldn't have to read it in the media. At that time, the family members were shown very recent pictures of Scott and a girlfriend. Okay, first of all, I met Scott Peterson November 20th, 2002. Scott told me he was not married. We did have a romantic relationship. I'm very sorry for Laci's family. And the pain that this has caused them. And I pray for her safe return as well. Amber Frey had contacted Modesto police department on Monday, December 30th, 2002. She met with detectives and gave information about the relationship with Scott Peterson. And amber Frey has been eliminated as a suspect in Laci Peterson's disappearance. Amber Frey was a single mother who was fixed up with Scott Peterson through a friend. She was his girlfriend and she thought she had met the man of her dreams. You know, in my mind we could be wonderful together. I was just starting my career in massage therapy. You know, my daughter was very young, very small. And a single mother. He was good looking, he was nice, he was funny and attentive to me. I felt like we had a connection. That conversation was easy. He was courting her. They had a whirlwind romance in the few weeks they knew each other. On the very first night, Scott meets her at the hotel and basically, he's smooth, but he gets her to go upstairs with him just for he can take a quick shower and change and then they can go to dinner. Well, upstairs is, you know, I don't know, four or five dozen roses and some chocolate strawberries and champagne, and that was the start of the relationship. You know, when you look forward to hearing from somebody and seeing them again, and that, you know, that excitement's there, and you could, you know, it -- you know, it all felt very good. She talked about, you know, laying out and looking at the stars, and Scott wanting to, you know, spend the rest of his life with her, and she really thought she had Mr. Right. I really liked him, and felt really good about where things were going, and our conversations and time spent together. Amber Frey was not his first lover outside the marriage. Okay? I mean, that's a given. Scott and Laci went to San Luis obispo, to college, and they were married while they were in college. They got married, and during that time he -- he got into another -- a relationship with another student down there, and she came forward. She had pictures. She had presents. She had roses. She had chocolate strawberries. I thought I was reading the whole thing over again about amber. The only thing that had changed is that Laci got pregnant. Scott Peterson no longer wanted to be in a marriage. He wanted to be a bon vivant, a man about town. I remembered asking him if he had ever been married, and he said no. But that wasn't true, of course. And, as it turns out, amber's friend who introduced her to Scott, found out that he was married. And confronted him, and said, "If you don't tell amber, I will." So, Scott did tell amber. He was very emotional. And said that this would be the first holidays without her. And he was crying at that point. I took it as, she died, didn't know how, if, you know, an accident or cancer or I had no idea, I didn't pry to ask. He just said it was painful and so I'd asked if he was ready for a relationship, like -- and he said yes. She was obviously a girl who had been duped. She was a girl that thought she was going to meet a nice guy, and that nice guy turned out to be Scott Peterson, who was a married man with a missing wife, who, took it to a whole nother level in terms of deceit. She didn't know about Scott and Laci missing until her friend told her, "Hey, that guy you brought to the Christmas party? He's on TV every day." And so, I went to the other room and called the Modesto police department hotline that they had. I was in shock. I mean, I literally was in shock. We had two full-time dedicated clerks that were manning the tip line. I'm standing behind our clerk and she's typing and I'm watching and it's, Scott Peterson is my boyfriend, I met him on November 27th, we've been dating exclusively. He said he wasn't married, and I'm like, Bev, is -- is that lady on the phone? Yeah, and so I talked to her and it was amber Frey and -- Couldn't get any words out for a while. And I was like, it is him. Like it -- this is him. And I'm like okay, don't go nowhere, I'm going to come visit you right now. Amber Frey started cooperating with police as soon as she learned that the man of her dreams was really a married man whose wife had disappeared and he had been lying to her all along. I buy her a tape recorder with some cassette tapes and a wire that can hook on to her phone, and I tell her, "Okay, if he ever calls, just push these two buttons, and just talk Normal." The phone rings, and it's Scott Peterson. I'm like, "That's him. Showtime, girl." Amber, hey, happy new year's. Happy new year's. Glad I caught you. Thank you. What they heard on December 31st, 2002, was a Scott Peterson who, while a candlelight vigil is being held for his missing wife and he's attending it, is also on the phone with amber Frey being recorded unbeknownst to him telling her that he's in Europe. I'm near the eiffel tower. New year's celebration is unreal. There's a big crowd. Huge. The crowd's huge? He was right down the street where the vigil was taking place. Okay? It was incredibly bizarre. You've got -- this guy's wife is missing, the entire country is looking for her, and he's not only keeping his girlfriend at bay, he's entertaining her with these outlandish lies. I kind of remember the area here. Mm-hmm. But not really that well at all down to the main square. M hmm. Which is kinda neat, isn't it? Church in the background. Yeah, I don't even really, you know -- I mean I've the only times I've really seen Paris is, you know. I'm in Brussels now. Oh yeah, that's right. You took the train to Brussels. Yeah. Amber Frey was critical to the case because she provides a motive for why now? Why is he killing his wife now? It was almost like a-ha. Now the motive, not only becomes clear, it's personified. There she is, he killed Laci to be with this woman. Instantly, as soon as amber Frey showed up, people are like, he's guilty. He is guilty. You didn't want to be on TV because you didn't want this girl to come out and make you look like an idiot. For me, I was the opposite. I thought, oh, my gosh, this explains it. This is not a killer. He's a cheater. It wasn't just that he'd had an affair. It was that he was continuing to pretend as if his wife wasn't missing. You were more worried about her than you were Laci. How dare you? To commit a crime like this, you have to have a screw loose at the very least, and those amber Frey tapes made it seem like Scott Peterson has a screw loose. He now is enemy number one. Everybody hates Scott Peterson. Scott, answer some questions. Did you murder your wife? ??? ???
This transcript has been automatically generated and may not be 100% accurate.