Laci's Dog Could Help Collar Scott

Laci Peterson had stopped walking her dog weeks before she vanished, friends say, countering her husband's theory that she was abducted while taking the dog out on Christmas Eve in 2002.

Prosecutors who charge that Scott Peterson murdered his wife and their unborn child contend that she stopped walking the dog weeks before, at her doctor's urging, and that Peterson is lying.

As the trial entered its fourth week Monday, Laci Peterson's friend Stacey Boyers wiped away tears as she described the last time she spoke with Laci and the frantic scene at the Petersons' home on the day she was reported missing.

Boyers, who had known Laci since the 3rd grade, also testified that Laci complained of being very tired in the last weeks of her pregnancy, reports CBS News Correspondent John Blackstone.

"She told me that it didn't seem like it was the holidays because it was kind of depressing," Boyers said. "Every time she would start to do something she would have to stop and rest."

Two other friends of Laci also testified that she had stopped walking the couple's dog.

Testimony Tuesday was expected from more friends and the lead investigator in the case, Detective Al Brocchini. Defense attorneys will try to show that Brocchini bungled the investigation, never considering any suspects other than Scott Peterson.

Scott Peterson claims his wife planned to walk the couple's dog the morning he left for a solo fishing trip and returned to an empty home. Prosecutors allege Peterson, 31, dumped Laci's body into San Francisco Bay, using the fishing story as a cover-up.

Defense attorney Mark Geragos raised questions about the police theory while cross-examining Debra Wolski, Laci Peterson's prenatal yoga instructor who also testified to Laci's weakened state.

Geragos pointed to a police report in which Wolski said that Laci told her the only exercise she got was walking the dog in the morning. On the witness stand Monday, Wolski said Laci told her she had stopped walking the dog.

Police "just manufactured this statement?" Geragos asked of the report.

"I don't know," she replied.

"Either the witness didn't tell the truth on the stand or the D.A. isn't providing evidence in a timely fashion," former assistant district attorney Michael Cardoza told CBS News.

Court TV's Catherine Crier, a former judge, disagrees.

"As long as the prosecution turned over the witness list and they knew who was coming in, it's not an exculpatory statement, so it's up to the defense counsel to interview on their own," she told CBS News Early Show co-anchor Harry Smith.

Meanwhile, Judge Alfred A. Delucchi decided that a juror captured on videotape having a brief conversation with Laci's brother could remain on the panel.

Testimony was delayed Monday morning as attorneys met with Delucchi in chambers to question Brent Rocha and Juror No. 5. "The court is of the opinion that there was no misconduct," the judge later said.