A state crime lab was working to determine whether two bodies found on the shores of the San Francisco Bay were Peterson and the baby she was carrying when she vanished Dec. 24. She was eight months pregnant at the time.
"If I were a betting man, I'd put money on it," Stanislaus County District Attorney James Brazelton told the Modesto Bee for a story published Thursday.
"I feel pretty strongly it is (Peterson)," said Brazelton, whose jurisdiction includes Modesto. "It's too much of a coincidence to have a female and a baby found close to each other a day apart and no others were reported missing."
Asked about Brazelton's comments, Laci Peterson's stepfather, Ron Grantski, said Thursday that he had not been told that personally. "Our family is waiting until we are told personally, not told by the press," he said.
Along San Francisco Bay where the bodies washed up with the tide, Tracy Shelton brought flowers to lay among the rocks.
"I've never done this before," she sobbed, "but I'm very compelled now."
And like Brazelton, Shelton too is convinced the bodies are the remains of Laci Peterson and the baby she was carrying when she vanished.
"I know it's her," she told CBS News Correspondent John Blackstone, "and I'm just glad she's come back to us, to help us find what's happened to her. She's the only one who knows."
State Department of Justice spokesman Nathan Barankin told the paper that lab technicians had determined that samples from the infant's body, found Sunday, contained enough intact DNA to be used for testing. A determination was expected Thursday on whether enough DNA could be extracted from the woman's body, found Monday.
"We've determined that we can yield a usable DNA profile from the fetus sample," Barankin said. "We're doing a little more work on the adult sample to finally determine whether we will be able to get a usable DNA profile."
Earlier, lab supervisor John Tonkyn had said, "We don't have another person in mind" other than Peterson.
When asked why dental records weren't being used, Tonkyn said the lab wasn't provided with teeth. Published reports have said the woman's body was headless. The full-term baby still had an umbilical cord attached.
The 27-year-old substitute teacher vanished on Christmas Eve from her home in Modesto, 90 miles southeast of Richmond. She was eight months pregnant. Her husband, Scott Peterson, said he saw her as he left to go fishing that morning in Berkeley, not far from where the bodies were found.
Scott Peterson, 30, a fertilizer salesman, hasn't surfaced publicly since the bodies were discovered by people walking dogs. His in-laws stood by him early in the investigation, but a rift developed after he acknowledged having an affair with a Fresno woman.
Scott Peterson has not been named as a suspect in his wife's disappearance, but police have seized his boat, truck and nearly 100 items from his house.
His father, Lee Peterson, said Tuesday at his house north of San Diego that he didn't know where his son was.
"If he comes out innocent, I think we'll all feel badly and go out and apologize to him, but right now he makes people nervous," said Modesto resident Kim Grise.
While his in-laws stood by him early in the investigation, a rift developed after Peterson acknowledged having an affair with a Fresno woman and traded in his wife's Land Rover for a new pickup truck.
Laci Peterson's father, Dennis Rocha, told CBS station WBZ-TV in Boston Wednesday that he thinks it's only a matter of time before his son-in-law is charged in the case.
"I just can't see Scott being out there free," Rocha told the television station. "That would just eat me up." He predicted that an arrest "will happen very soon."
The property manager of the building where Scott Peterson rented an office, who identified himself only as Mark, said Peterson moved out earlier this year and is trying to find someone to take over the lease.
If the woman's body is not identified as Peterson's, the lab will begin comparing the samples with likely matches in a database of 100 DNA samples of other missing people or their relatives. The state has more than 25,000 active missing person cases.