Laci's Mom Suspicious Right Away

Laci Peterson's mother knew something was "very seriously wrong" when Scott Peterson called on Christmas Eve 2002 and said his wife was missing, prosecutors said Tuesday morning as opening statements began in Peterson's murder trial.

Prosecutor Rick Distaso told jurors that Scott Peterson called his mother-in-law that afternoon and said he had returned from a fishing trip to an empty house — though he allegedly later told her uncle he was golfing all day.

"He says, 'Mom, Laci's missing,"' Distaso told jurors. "Right then, Sharon Rocha knew that things were very seriously wrong."

"It's Christmas Eve, there's a woman who's eight months pregnant who is missing under very mysterious circumstances," Distaso told jurors, over objections from defense attorneys. "They're looking for evidence of a burglary. They're looking for evidence of a robbery. There is nothing out of place."

They did find a loaded .22-caliber handgun in the glove box of Peterson's truck, said Distaso. The gun also was mentioned at pretrial hearings.

Rocha joined investigators in a panicked search of garbage cans at a fog-shrouded park near the couple's Modesto home, where Laci Peterson used to walk the family's golden retriever.

Distaso described Scott Peterson as terse with his in-laws and unable to tell police what he had been trying to catch during his fishing trip on San Francisco Bay.

By Christmas Day, Peterson was more engaged and talking in ways that Distaso suggested point to his guilt. For example, he said, Peterson called police to ask if they were using cadaver-sniffing dogs to search the park.

"'We haven't come to the conclusion yet that Laci Peterson is dead,"' Distaso said the officer told Peterson. "That kind of sets the stage for this entire case."

Prosecutors have had more than a year to prepare their case — which California Attorney General Bill Lockyer called a "slam dunk" on the day authorities arrested Peterson.

But the trial's opening statements started with prosecutors facing their own obstacles — the absence of a murder weapon, a cause of death or an eyewitness to the alleged crime.

They allege Peterson killed his wife in their Modesto home because he was having an affair, then drove her body nearly 100 miles to San Francisco Bay and heaved it overboard from his small boat.

Defense attorney Mark Geragos has countered that Modesto authorities unfairly targeted Peterson, ignoring important leads that didn't fit their theory. Geragos' presentation was to follow the prosecution argument.

Peterson, 31, could face the death penalty or life without parole if convicted in a trial that is expected to last up to six months.

The bodies of Laci Peterson and her fetus, a boy the couple planned to name Conner, washed onto a bay shore in April 2003, near where Peterson told authorities he set out on a solo fishing trip the morning his wife vanished.

Prosecutors were expected to use many of Peterson's nearly 3,000 telephone conversations that police recorded after his wife's disappearance. Likely among the most damaging, experts say, are calls with his mistress, Amber Frey, who cooperated with authorities soon after Laci Peterson vanished.

On Tuesday, Judge Alfred A. Delucchi gave jurors the standard admonishment that circumstantial evidence cannot lead to a finding of guilt unless the facts "cannot be reconciled with any other rational conclusion."

Geragos has offered innocent explanations for the behavior of his client, who was carrying more than $10,000 cash and his brother's driver's license and had dyed his hair blond at the time of his arrest, not far from the Mexican border.

He also has floated a series of explanations for the crime, including that members of a satanic cult abducted Laci Peterson and that the "real" killer framed Scott Peterson after learning his alibi.

It took more than two months to find 12 jurors and six alternates in this county just south of San Francisco, where the trial was moved because a judge didn't think Peterson could get a fair hearing in the couple's hometown.

"We are certainly going to hear more detail about the prosecution's theory of the case than we've heard before," says CBS News Legal Analyst Andrew Cohen. "Unless they've hidden their best evidence until now, prosecutors are trying to get a capital conviction against Scott Peterson without having a murder weapon or a specific cause of death. And that's not going to be easy, especially with the good defense attorneys Peterson has."