Transcript for Neighbors report suspicious activity to investigators in Laci Peterson's case: Part 4
The bay searches started -- I believe it was the end of December or thereabouts. They were also doing searches in the freshwater reservoirs up in the Sierras. But when it came to the bay searches, that was pretty widely publicized because Scott had maintained that -- you know, his alibi was he went fishing you know at the Berkeley marina launching his boat. He said he went to the bay. He had proof he went to the bay. We believed she was in the bay, so we're searching the bay. So to believe that Scott's guilty, you have to believe that someone bought a brand new boat that they'd never had in the water before and then took this boat to the busiest marina on the San Francisco bay, you know, to dump his wife's body in broad daylight. It just defies logic. I'm a very cynical person when it comes to spousal mystery. I always blame the husband, and I am almost always right. I start with the presumption that the husband did it, but there were alternative theories. One is she was kidnapped by a satanic cult. Another one was a burglary that was across the street from the Peterson home. You had a neighbor, Diane Jackson, who saw three men in a van in front of the Medina home on December 24th at about 11:40 in the morning. I was coming down covena towards the park, going past Laci on one side and Medina's on the other. And I just looked over and there were three guys on Medina's property in a van out front. And the only reason it caught my eye is that they turned around looked at me. Sort of made me think -- feel a little bit uncomfortable. When this information came out, immediately there was a sense that, okay, maybe Laci was walking the dog, came across this burglary, and that's what happened to her. This was a viable explanation. Maybe she confronted the burglars, something happened, and they kidnapped her. We caught the guys that went in there and broke into that house and interviewed them. They talked about the abduction. They said we don't want -- our hands clean on that. Also there were people who say they saw her walking her dog at a time after Scott Peterson left to go fishing. And if so, then obviously she wasn't dead in the back of his truck when he left. We had a tip line up 24/7. As far as the tips are concerned, some of the people who actually saw Laci that they should have talked to, they never did talk to. So these are the people who were calling in, responding to the police. People are seeing Laci walk the dog after he left. Modesto police department or the investigators, they never came to ask me anything. On the day after Christmas, when I -- after I talked to the motorcycle policemen and gave them my statement that I had seen the dog in the park, nothing was followed up after that. I just figured people who know better than I and knew more about the case had pretty much made a decision that what I had to say wasn't all that relevant. If anyone saw her after 10:00, then that let Scott out, and that would be horribly inconvenient. Then the Modesto police department would have to admit, we have no idea who killed this beautiful pregnant woman. We actually found the pregnant lady with a golden retriever that walked her dog on that day, and the conclusion was that was not Laci and mckenzi. It appears that the description was somewhat different, and we're not sure it was her. And yet, at the same time, they're having press conferences and they're saying, we cannot confirm she was walking the dog. So they're creating a public perception that Laci didn't walk her dog, which leaves them free to say that Scott was the last person to see his wife alive. I mean, it's true the police needed to look at other possibilities, but they needed to stay on Scott. They needed to do what they did. I spent a great deal of time with the police and been forthcoming with the police in every instance. Is it possible they think you know where she is? I think a lot of people believe that. Are you afraid police will arrest you? No. I know there is -- there's no basis. I had nothing to do with her disappearance so there is no possible evidence or anything like that. There's absolutely no physical evidence at all that Scott committed this crime. We pretty much dealt with all of the satanic cults, the dog walkers. The only thing we couldn't eliminate was Scott. I'm Laci's mother-in-law and Scott's mother, and I want to thank all of you for the love and outpouring. So, now there's a big memorial for Laci in Modesto, candle light memorial. I thank everybody for coming out here tonight. Laci would be so happy to see she had so many friends and supporters. And just keep looking for Laci. Please don't give up. There were a lot of people who came to that vigil in the park. Lord, tonight we lift Laci Peterson to you, father. I do remember I didn't see Scott the entire evening. He was there apparently, but I didn't see him. The only thing I saw were the pictures in the media from him that night. Never saw him. They ask about the candlelight vigil in the park, and they ask, why weren't you on that stage with the family? And frankly because this isn't about us, to be out in front of the camera. It's about us to work towards bringing home the one person who's hurting the most, the piece of our family that's missing right now. We are kindling a fire in this cold world full of hatred and selfishness. Our little blaze may seem to be unveiling. There's a vigil going on for Laci, a candlelight vigil. And I say, well, where's the husband? Well, I'll tell you where he was. He was off in the corner talking on the phone to his mistress amber Frey. And she recorded it. Amber, it's me. Are you there? Yes. Are you having a good time? I'm, um, near the eiffel
This transcript has been automatically generated and may not be 100% accurate.