Laci's Final Day

The day before she was reported missing, Laci Peterson spent what appeared to be a routine day preparing to host Christmas dinner with her family — she went grocery shopping, visited a spa and made sure the house was clean.

A series of prosecution witnesses Thursday reconstructed her comings and goings on Dec. 23, 2002, the last day that prosecutors say anyone besides her husband — and alleged killer — saw her alive.

Prosecutors have charged Scott Peterson with murdering his eight-months-pregnant wife on or around that Christmas Eve, then driving her body from their home in Modesto to San Francisco Bay and dumping it from his small boat. Peterson, 31, could face the death penalty or life without parole if convicted.

While the trial began this week with sweeping claims of his guilt or innocence, it resumed Thursday with mundane details of Laci Peterson's holiday preparations.

Two days before the couple was to host Christmas dinner, Laci Peterson spent nearly $100 at a Trader Joe's grocery store, buying 24 items, including salmon, eggs, shrimp and soup, according to store employee Fred Eachus.

Just after noon, she went to the Sweet Serenity Day Spa for a waxing treatment, owner Michelle Buer testified. Unlike many of her other clients, Buer said, she never complained about her husband, though she did mention that she was uncomfortable and not sleeping well.

Those and other details emerged the day after Peterson's defense attorney made a bold claim that Laci Peterson's son was born alive -- and, therefore, Scott Peterson could not have been the killer.

Mark Geragos' surprising promise, which one legal observer called "dramatic, but dangerous," highlighted the defense's two-hour opening statement Wednesday.

"If this baby was born alive, clearly Scott Peterson had nothing to do with this murder," Geragos said. "The evidence is going to show that (Laci) was alive on Dec. 24 when Scott went to the marina."

Prosecutors say the boy, whom the couple planned to name Conner, died in the womb.

Geragos indicated he will call experts to testify that the fetus was older than it would have been if it died at the same time as Laci, and that the umbilical cord was cut in such a way that the child must have been removed from Laci Peterson while still living.

Prosecutors have said their experts will testify that the fetus was expelled well after Laci Peterson's corpse was dumped into San Francisco Bay.

Geragos' maneuver took some legal observers by surprise. Robert Talbot, a professor at the University of San Francisco School of Law, called it "dramatic, but dangerous."

"But if he can do it, it will go a long way to reasonable doubt," Talbot said.

Geragos' opening statement was the first formal glimpse inside a strategy to clear Peterson by suggesting that somebody else was the killer.

Prosecutors have portrayed Peterson as a lying cheat who killed his wife because he was having an affair with massage therapist Amber Frey — and because he wasn't ready to become a father.

Geragos countered Wednesday that while the former fertilizer salesman had a mistress, it doesn't mean he killed his wife.

"He's not charged with having an affair. ... The fact of the matter is that this is a murder case and there has to be evidence," he said.

Geragos downplayed Peterson's interest in Frey, saying they only went out on two dates, and characterized him as a giddily expectant father who accompanied his wife to all her doctor's appointments.

"Mark Geragos has an uphill battle to change perceptions about his client and I think he's off to a good start. His opening statement makes sense with what he has to deal with; he's not telling jurors that his client is a saint, he's just telling them that a cheating husband isn't necessarily a murdering husband," says CBSNews.com Legal Analyst Andrew Cohen.

During his opening statements Tuesday, prosecutor Rick Distaso didn't promise jurors they would hear about a murder weapon or an eyewitness to the crime, and Geragos seized on the circumstantial nature of the case.

Authorities in the couple's hometown of Modesto secured more than 100 bags of material from Peterson's home, car and warehouse, and state crime lab scientists analyzed the evidence exhaustively, Geragos said.

"What did they get out of all those tests? Zip, nada, nothing," he said.

Wednesday's session closed with testimony from the first prosecution witness — the Petersons' housekeeper, Margarita Nava. Nava testified in Spanish that she cleaned the kitchen floor Dec. 23.

Prosecutors contend Peterson also cleaned and mopped his kitchen after killing his wife, and have seized the mop as evidence.