Closing arguments were set to begin Monday, with prosecutors telling jurors why they believe Peterson should be convicted of two counts of murder in the deaths of his pregnant wife, Laci, and the fetus she was carrying.
The prosecution argument was to be followed by the defense and then a prosecution rebuttal. Jurors are expected to begin deliberations as early as Wednesday.
Jury selection in the trial began in March. Opening statements began June 1.
Prosecutors claim Peterson killed his wife on or around Christmas Eve 2002, then dumped the weighted body into San Francisco Bay. The remains of Laci Peterson and her fetus were discovered along a rocky shoreline about four months later, a few miles from where Scott Peterson claims to have gone fishing alone the day his wife vanished.
Prosecutors put together a detailed web of circumstantial evidence to cast suspicion on Peterson, 32, but couldn't point to a murder weapon, a crime scene or even a cause of death.
Defense lawyers claim someone else abducted and killed Laci.
For lead prosecutor Rick Distaso the challenge is to distill a massive and often rambling case into a convincing story for a jury that has listened to 188 witnesses over five months, reports CBS News Correspondent John Blackstone.
The challenge for defense attorney Mark Geragos may be to live up to his opening statement in which he promised to prove Scott Peterson is innocent of murdering his pregnant wife Laci — proof that never showed up in court.
"The evidence is going to show clearly, beyond any doubt, that not only is Scott Peterson not guilty, but Scott Peterson is stone-cold innocent," Geragos said then.
"If Geragos in his closing argument doesn't address why he didn't put those things on, if I were the prosecutor, I would hang him by that," said former prosecutor Jim Hammer. "And jurors tend to hold that against lawyers. When they promise something and don't deliver, the juror will begin to wonder why."
In their closing, prosecutors will almost certainly try to use Scott Peterson's own words against him, replaying wiretapped phone calls to Amber Frey, the other woman in his life. Prosecutors will remind jurors that in those phone calls and in television interviews, Peterson was caught in a string of lies.
"Their argument is going to be that common sense and human nature tell us only the person that was responsible for the death could have comported themselves in such a way," said former prosecutor Paula Canny.
In a victory for the prosecution, Judge Alfred A. Delucchi ruled Friday that jurors will be allowed to consider a lesser murder charge that would spare Peterson a possible death sentence if convicted
The jury must first believe Peterson planned the killing in advance in order to convict him on the first-degree murder charges. He faces the death penalty or life without parole, if convicted on those charges.
Convictions on the second-degree charges would mean jurors believed Peterson killed his wife but it wasn't premeditated. Second- degree murder carries a sentence of 15 years to life in prison.
"The jury could say, 'Well, we think that Mr. Peterson killed Laci Peterson but we're not persuaded beyond a reasonable doubt that there was premeditation,'" Delucchi said in his ruling — part of instructions that will be given to jurors this week.
Defense attorneys vehemently objected to the inclusion of the lesser charges.