Defense's Turn At Peterson Trial

Attorney Mark Geragos Monday will open his case in defense of Scott Peterson by attacking a central prosecution theory: that Peterson used homemade concrete anchors to carry the body of his pregnant wife Laci to the bottom of San Francisco Bay.

CBS News Correspondent John Blackstone reports Geragos also will challenge prosecution evidence that Conner, the baby Laci was carrying, died in her womb. He made that promise to jurors at the very beginning of the trial.

"Where he takes a chance is to say that he is going to prove that Conner was born alive," law professor Robert Talbot told CBS News. "Right at the end you don't want jurors remembering back from the opening statement that he said he'd show us this and he didn't."

Where he's unlikely to take a chance is putting Peterson on the stand. The witness stand can be a dangerous place for a defendant.

Cross-examination by the prosecutor can be brutal. Objections from defense attorneys can look like an attempt to hide something. And the way the defendant looks and acts on the stand can prove more powerful than what he or she has to say.

"Even innocent defendants can look guilty on the witness stand," said Loyola Law School professor Laurie Levenson.

In nearly 19 weeks of trial on charges of killing his wife, Laci, and the fetus she carried, Peterson has already become his own worst witness. Through wiretapped phone calls and videotapes played in court, the jury has seen and heard him carrying on an affair and lying repeatedly to girlfriend Amber Frey, to reporters, to police, and to friends and relatives.

"Peterson is a compulsive liar," Levenson said. "If he takes the witness stand, the prosecution has such an easy way to undermine his credibility. If he's willing to lie about small things to Amber Frey and to family members, imagine what he would lie about if his life were on the line."

Defense lawyers have tried to explain away his behavior as that of a man on the run from a crush of media — not from police, as prosecutors claim. When the defense begins presenting its case next week, his attorneys may point to another reason for his seemingly odd and evasive actions — death threats that had Peterson fearing for his life.

That could help him explain why, for example, he had dyed his hair blond and had left his hometown of Modesto by the time he was arrested.

But the risks involved in taking the stand might still be too high.

"I would be worried that Peterson would come off smirky, too clever or arrogant," said Michael Mello, a Vermont Law School professor who served as one of serial killer Ted Bundy's attorneys on appeal and wrote a book about Unabomber Ted Kaczynski.

"The risk is confirming the jury's suspicion that this guy ... really is as much a slime as he appears to be," Mello added. "My mother used to have a saying: `It's always better for people to wonder why you didn't open your mouth than to have people wonder why you did."'

Putting him on the stand "would really be a huge mistake in a case like this ... because it would throw away all of the benefits of being able to say they simply haven't proved their case," said Peter Keane, a professor at Golden Gate Law School.

Peterson, 31, could get the death penalty if convicted. The bodies of Laci Peterson and her fetus washed up along San Francisco Bay, about two miles from where Scott Peterson claims he was fishing alone on Christmas Eve 2002, the day his wife disappeared. Prosecutors say he killed her so that he could carry on with Ms. Frey.

Both sides are bound by a gag order, and Peterson's lawyers have not said what they are going to do. But his attorneys did at least consider putting him on the stand. They even took time early on to prepare him, in case they felt a win slipping away.

Geragos has been the undisputed star in this courtroom.

"He's really well prepared. He knows his case, has good control in the courtroom," said former district attorney Terence Hallinan. "He is not afraid to get up and walk around and point things out and he just comes through as a nice, likeable guy."

The defense has floated multiple theories about how someone else could have killed Laci and the baby, but those theories haven't adequately explained motivation for a frame-up, Court TV's Beth Karas, a former New York city prosecutor, said.

"For someone else to have killed his wife and baby and then framed him, this is personal for them," Karas said. "It's an act not against Laci and the baby, but an act against Scott. Who would do that? Not a stranger, but someone who had a beef with him. And that's not even part of the case."

Closing arguments are expected Nov. 1 or 2.