Police have also evidently focused on whether concrete blocks were used to weigh down Laci's body. On Dec. 26 they seized Scott's boat, which had been purchased only three weeks before Laci's disappearance, and asked the couple who sold it to him to look the 14-ft. vessel over. The couple noted there was a powdery, cement-like residue that hadn't been there before. Peterson's mother, Jackie, has pointed out that Scott used a concrete anchor, which could account for the residue. All the same, during a search of the Peterson home on Feb. 18, police reportedly removed containers of cement along with 95 items of evidence. According to CNN, authorities have used sonar to pinpoint a spot in San Francisco Bay where the concrete weights may still be lying on the bottom – and will now seek to compare anything they find there with the samples linked to Scott.

Evidence aside, Scott's behavior itself had raised suspicions. There was, for instance, his account of how his wife went missing. He said he had bid Laci goodbye on the morning of Christmas Eve and driven 90 miles to the Berkeley Marina so that he could go fishing for sturgeon. When he returned later that day she was gone. But Jim Cook, a Modesto field representative for a wireless company who often fishes the waters of San Francisco Bay, points out that it would be unusual to go fishing for an enormous fish like sturgeon in such a small craft or to do so in the middle of the day, when early mornings are best. Says Cook: "Something doesn't add up." Including, to some, the day that Scott chose to go. "It was Christmas Eve and she was pregnant," says Dr. Carole Lieberman, a Beverly Hills psychiatrist who has been an expert witness in many court proceedings. "Who leaves their pregnant wife alone to go fishing?"

There were also indications that Scott had been less than fully cooperative with police. While he sat for interviews with investigators, he neglected to mention a key detail: that he had been having an affair with another woman, a Fresno massage therapist named Amber Frey, 28, who came forward to cops on her own and went public with the news on Jan. 24. Demonstrating that he was, if nothing else, a cad, Scott insisted that his missing wife had found out about the affair and accepted it – a notion that infuriated Laci's family, who until then had voiced support for their son-in-law. "Had she known, she would have been devastated, and that wasn't obvious to her friends or family," Sharon told PEOPLE. "There wasn't any reason to suspect that there were problems."

And there were other little things. Like the fact that witnesses saw him laughing at a vigil for Laci days after she vanished. Or the $250,000 life insurance policy he had taken out on his wife after she became pregnant. (Scott has said that both he and Laci had policies in the same amount for investment purposes.) Or the interview he gave to ABC's Diane Sawyer in January, in which he at times sounded almost nonchalant in discussing his wife. Or his selling Laci's Range Rover a month after the disappearance and buying himself a Dodge pickup. Or talking to a realtor about selling their home. "Laci loved her home," says Sharon, 51, who was given back her daughter's car by a dealer. "She spent a lot of time working on her house, she enjoyed all that. And if someone did take her, where was she going to come home to if it was sold?"

This is an excerpt from our Cover package. For the complete story, please pick up the May 5, 2003, issue of PEOPLE.

– BILL HEWITT
– LYNDON STAMBLER, JOHNNY DODD, FRANK SWERTLOW and RON ARIAS in Los Angeles and MELISSA SCHORR in Modesto