Jurors deciding Scott Peterson's (search) fate may have hit a snag after less than a week of deliberations.

Judge Alfred A. Delucchi (search) summoned the panelists to the courtroom Monday morning where he reissued instructions on several key points and lectured them about the importance of keeping an open mind.

"The people and the defendant are entitled to the individual opinion of each juror," the judge said. "Do not hesitate to change your opinion for the purpose of reaching a verdict if you can do so.

"The attitude and conduct of jurors at all times is very important," Delucchi added. "It is rarely helpful for a juror at the beginning of deliberations to express an emphatic opinion on the case."

The jurors listened with grim expressions before they were sent back into the jury room to resume deliberating. It was not immediately clear what prompted the judge's instructions.

Trial observers speculated jurors could possibly be reaching a stalemate. "They're stuck," said Jim Hammer, a former prosecutor and trial regular. The judge "clearly has indications that they're beginning to hang."

Deliberations were to resume Tuesday.

Peterson is charged with two counts of murder in the deaths of his wife, Laci, and the fetus she carried. Prosecutors claim Peterson killed Laci around Dec. 24, 2002, then dumped her weighted body from his boat into San Francisco Bay. The remains of Laci and the fetus were discovered a few miles from where Peterson claims to have gone fishing alone the day his wife vanished.

After hearing from the judge Monday, jurors asked to review numerous pieces of evidence, including San Francisco Bay tidal charts seized from Peterson's computers; an anchor found on Peterson's boat that prosecutors allege is similar to the ones he used to sink his wife's body; and transcripts and recordings of telephone calls between Peterson and his mistress, Amber Frey.

They also requested information regarding a life insurance policy on Laci Peterson; a two-day fishing license Peterson purchased on Dec. 23; and a transcript of a police interview of Peterson regarding his whereabouts on the day his wife vanished.

Earlier, jurors inspected Peterson's 14-foot aluminum fishing boat, which was brought to the courthouse. They examined the sides and looked under the craft before a few jurors climbed inside and rocked it from side to side.

Defense lawyer Mark Geragos then sought a mistrial, claiming jurors violated the judge's order by doing "a juror experiment." The judge quickly denied the motion.

Defense lawyers have argued that it would have been nearly impossible for Peterson to have heaved his wife's 153-pound body over the edge of the boat without tipping.

As an alternative to a mistrial, Geragos asked the judge to be allowed to show jurors a videotaped experiment performed by the defense, apparently showing that the boat would have tipped over. Delucchi denied that request, as well.

Jurors have two choices should they decide to convict Peterson — first- or second-degree murder. First-degree convictions, carrying the death penalty of life without parole, would mean jurors believe Peterson planned the killings in advance. Second-degree murder convictions don't require a finding of premeditation, and carry sentences of 15-years-to-life for each count.