Rising tension on the O.J. Simpson jury erupted in open revolt today when 13 of the 18 sequestered panelists refused to go to court, halting the trial. Most trial watchers said the rebellion increases the likelihood the jury will be unable to reach a unanimous decision in the double murder case.

The angry jurors initially refused to board the bus that shuttles them from their first-class hotel to the courthouse and demanded that Judge Lance A. Ito meet with them to hear their complaints, according to the Los Angeles County Sheriff's Department.

After the judge declined and ordered them to come to court, four jurors arrived dressed entirely in black and nine wore some black clothing. Sheriff's sources said the black attire was intended as a protest over Ito's decision Thursday to reassign three sheriff's deputies who had been guarding the jury and recently were the subject of a dismissed juror's complaints.

Some of the 12 jurors and six alternates reportedly left the courthouse in tears Thursday after Ito told them he had removed the deputies, who had been tending to the panelists for the three months of their sequestration.

Ito canceled testimony for today and Monday and interviewed seven jurors today. The judge's spokeswoman said the court will not release transcripts of any of the judge's juror interviews until his investigation into a variety of jury problems is completed.

Simpson's lead defense attorney, Johnnie L. Cochran Jr., was among those present during the juror interviews today. "I couldn't characterize it as angry," Cochran said of the juror comments. "Some concerns were expressed on all sides and we're trying to look at those concerns."

Cochran said he believed it was "highly improbable" that the jury rebellion would provoke a mistrial at this point.

Legal analysts said the rare mutiny could derail the trial, but most predicted that Ito would resolve the jurors' problems and prevail upon them to complete the case.

Some analysts said signs of such deep dissension three months into the trial strengthened expectations that the panel would be unable to reach a unanimous verdict on whether Simpson killed his ex-wife, Nicole Brown Simpson, and her friend, Ronald L. Goldman, last June 12. But other trial watchers said the mutiny demonstrated bonding among jurors and indicated they could make a decision.

"A hung jury has always been the most likely outcome," said Peter Arenella, a law professor at the University of California at Los Angeles. "This only increases the probability."

Los Angeles defense attorney Barry Tarlow called the mutiny "astounding behavior" that reveals "deep divisions on this jury. . . . This is clear evidence that there's going to be a hung jury."

At least one jury expert speculated that the evident jury bonding may make it easier to reach a verdict. "This could be a turning point," said Thomas Hafemeister, a lawyer and psychologist who has studied juror stress. "A large number are coalescing and forming a group . . . which tends to release stress because they no longer feel isolated. It may make things much easier for them in the future."

Police Detective Philip Vannatter, one of the lead investigators in the case, agreed, saying that signs of juror "solidarity" show that "this jury can come to a decision."

Tensions on the jury, including shoving matches and racial divisions, had been rumored since shortly after the panelists were sequestered in mid-January. The group began with 12 jurors and 12 alternates. Six jurors have been dismissed by Ito for a variety of reasons, including lying on their court questionnaires, writing a book on the trial and sharing a doctor with Simpson. The remaining panel and alternates include 12 African Americans, four whites and two Latinos; 14 are women and four are men.

Details of the dissension burst into public view earlier this month when Ito excused juror Jeanette Harris, an African American woman who claimed the panel was deeply divided by race and that the strife was exacerbated by sheriff's deputies who gave preferential treatment to white jurors.

Harris's comments prompted Ito to interview each juror individually earlier this week. He has not released transcripts of those interviews.

Ito had planned to interview the deputies mentioned by Harris before taking action. But on Thursday afternoon, a 25-year-old African American female juror asked during a court break to be released from the case. A transcript of the conversation, inadvertently released, quoted her citing "a combination of things" over the past three months as the basis of her complaint that she couldn't "take it anymore."

Court sources speculated that the juror also complained about the deputies, because she remained on the panel while Ito ordered the deputies reassigned immediately after testimony ended Thursday.

This morning, the four jurors who dressed entirely in black included two white women, a black woman and a Latina. One juror who dressed as if in mourning was the 38-year-old white woman who Harris alleged had kicked her and another black juror and received preferential treatment from deputies while shopping and making telephone calls.

Another juror who dressed in black is a 60-year-old white woman who complained she needed air and opened a window in a van, according to Harris, who interpreted that to mean she couldn't "breathe the same air" as the black woman seated beside her.

Los Angeles County Sheriff Sherman Block objected to Ito's removal of the deputies as "premature" and inappropriate because the judge had not talked to the deputies first.

Despite Harris's complaints, jury experts were not surprised by the distress over the deputies because it is natural for jurors to become close to the officials who look after them. This tendency causes many defense lawyers to oppose sequestration for fear it will cause jurors to favor the prosecution, which can be seen as on the same side as the deputies.

"There's a close symbiotic relationship that tends to develop between court officials and jurors," Hafemeister said.

Several legal analysts said the issue of the deputies is probably just the outlet for jurors to vent a variety of frustrations that inevitably have built up during the lengthy trial.

The jury rebellion occurred on the 101st day of sequestration and halted what would have been the 57th day of evidence and testimony, according to a Court TV analysis.

The trial has included more than 400 sidebar conferences among lawyers, out of the jury's earshot, and 41 percent of the court time has been consumed by activity out of the jury's presence, according to a recent Los Angeles Times analysis.

Los Angeles District Attorney Gil Garcetti originally expected the prosecution to complete the presentation of its case by the end of March but recently said he hoped his side would finish sometime in May. Then the defense presents its case. Defense attorney F. Lee Bailey recently predicted a verdict by August.

"This is unprecedented. This is amazing," said Loyola Law School professor Laurie Levenson. "This is about as serious a jury problem as you're going to get."

Levenson said part of the problem has been the pace of the trial, which often has left jurors with "nothing to do but get on each others nerves." She said Ito needs to "move the case along . . . stop the lawyers' theatrics, keep the jurors busy, let them know there's a light at the end of the tunnel."

Other legal experts defended Ito, saying he has no choice but to let both sides make their arguments, however long it takes. "I don't fault Judge Ito," said Erwin Chemerinsky, a law professor at the University of Southern California.

Chemerinsky said the jury uproar is the inevitable result of the prolonged sequestration. Although he initially opposed sequestration, Chemerinsky said containment probably has done some good by protecting the jury from potentially damaging news reports about inadmissible evidence or witness problems, such as this week's reports of an author's allegations that former Simpson house guest Brian "Kato" Kaelin lied on the witness stand.

Ito has tried to relieve the stress of sequestration by allowing conjugal visits twice a week and arranging outings to the beach and sporting events and special entertainment, such as an appearance by "Tonight Show" host Jay Leno. Special correspondent Kathyrn Wexler contributed to this report.