For six hours a day, the jurors in the trial of D.C. Mayor Marion Barry focus on explosive and crucial issues: drugs, politics and the fate of the mayor of the nation's capital.

Then deputy U.S. marshals whisk them back to their hotel and this is what they give them: "The 'Burbs," a Tom Hanks movie about nasty neighbors; "Funny Farm," with Chevy Chase frolicking in the country; and "My Mom's a Werewolf" -- videotapes carefully chosen to avoid all the things the jurors must face each day in Courtroom No. 2.

The 18 jurors and alternates, sequestered at an undisclosed location since they were impaneled on June 18, talk on telephones that are monitored, sleep in rooms devoid of radio and TV, and read "sanitized" newspapers, each page screened and sheared of offending articles. The Washington Post and the Washington Times are simply off limits. And one weekend the New York Times contained so many stories about drugs, crime and trials that the marshals threw out everything except business news and sports before the jurors got a peek at their morning papers.

For these 18 sequestered souls, it's back to their rooms each night at 10:30 and wake up at 6:30 each morning, with deputy U.S. marshals as their constant companions. Jogging? A marshal jogs too. Tennis? A marshal is across that net. Recently, in an extraordinary outing, two marshals accompanied a juror to Kentucky so she could serve as maid of honor in a friend's wedding.

It is all part of a calculated plan to shield jurors from the prejudice of news reports and outside comment in perhaps the most public trial in the city's history.

Sequestered juries are rare. For the government, sequestration is an expensive proposition, and for jurors, one that is "quite intrusive," said former federal judge Susan Getzendanner, of Chicago.

It is a "last resort" for most judges, Getzendanner said. But with a defendant so well known and issues so compelling that they generate pervasive publicity and comment throughout the city, she added, "I can see why a judge would reach this conclusion" in the Barry case.

Perhaps because of their rarity, much about sequestered juries remains a mystery. But this is clear: Most defense lawyers don't like them, and sequestration adds its own dynamic to the delicate deliberative process.

"It's a wild card," said D.C. lawyer Abbe D. Lowell. "It makes for an unpredictable influence beyond the attorney's control."

Barry attorneys R. Kenneth Mundy and Robert W. Mance fought the sequestration, arguing that it could unduly prejudice the defendant's right to a fair trial.

U.S. District Judge Thomas Penfield Jackson rejected their motion, asserting that there were "compelling" circumstances to justify his decision.

Former Watergate prosecutor Richard Ben Veniste, who prosecuted John N. Mitchell and his codefendants in 1974 before a jury sequestered for three months, said it would be "extremely rare, absent compelling evidence," for an appeals court to take issue with a judge's decision to sequester.

And how might it play out in the jury's deliberations?

Some say the jurors hold it against the defendant for causing their involuntary confinement. Some say they take it out on the prosecutors.

But Lowell and others believe the effect is far more subtle. Defense lawyers, Lowell said, want to present their case to 12 independent-minded individuals.

"When they {the jurors} live together, they start thinking like a group far too soon," Lowell said. "It tends to be bad for the defense."

Prosecutors, to secure a conviction, need 12 jurors on their side. The defense can avoid conviction with one strong holdout. Jurors who cannot agree unanimously on a verdict cause a hung jury and a mistrial.

Defense lawyer Arnold M. Weiner, who has seen his share of sequestered juries, said sequestration "introduces an element of friends not wanting to disappoint one another."

"So the likelihood of a juror standing on principle and refusing to agree, irrespective of the wishes of the majority, diminishes significantly," he said. "That tends to work against the defense."

With Mundy's apparent strategy of seeking individual partisans on the jury, that element could be crucial, several lawyers said.

"Ken {Mundy} would not be unhappy with a hung jury," Lowell said. But with sequestration, the likelihood of that "is less and less."

Jury experts said the jurors could just as easily end up at each other's throats, unwilling to agree on anything.

Beth Bonora, of the National Jury Project in California, said the pressure is "quite incredible" in the jury room, particularly in high-visibility trials where jurors know their verdict will come under sharp scrutiny.

When jurors are not getting along, sequestration can nudge them in either direction, creating "pressure to get it over with and go home," Bonora said. That could lead to jurors' changing their minds against their better judgment, just to facilitate a verdict, she said, "or it can lead to a hung jury, when people give up trying to persuade one another."

Nothing, of course, in jury-watching is gospel. D.C. lawyer Plato Cacheris, who defended Mitchell in the Watergate trial, believes sequestration "has no bearing" on a trial's outcome. "I have never seen a bizarre verdict just because a jury was sequestered," he said.

During jury selection in the Barry case, some potential jurors made their feelings about confinement clear. Marsena Hall, one of those selected, stated flatly that she didn't want to be a juror "because I have to be sequestered."

Edward Eagles, who also was selected, said sequestration could be a burden on his elderly mother. To that, Judge Jackson replied, "You're not locked away in a tower somewhere. You can see your family under supervision."

Indeed, everything the jurors do is under supervision. Some weekends, they are taken home for a brief visit. There's time "to change clothes and say hello," said Floyd Johnson, a supervisory deputy U.S. marshal.

Jurors also have been taken on outings to the Inner Harbor in Baltimore and to Williamsburg, Johnson said. According to U.S. Park Police, they spent some time July Fourth at a paddock in Rock Creek Park where police horses are stabled.

Occasionally, there have been lunchtime breaks from the packaged sandwiches from the courthouse cafeteria. Big favorites at those times? Chinese food, pizza and chicken.

Three jurors have celebrated birthdays since the trial began, occasions duly noted with cakes.

Virtually every move the jurors make must be approved by Judge Jackson. He issued a June 18 order that set their routine, down to a decision that they be allowed up to "two cocktails" at dinner each night.

It is sequestration lore that jurors can get angry at whichever side in a trial seems to be dragging things out. Recently, Jackson has seemed concerned about that.

" . . . There are some restless people here that want to get to work," Jackson cautioned both sides at a bench conference last week.

And Friday, when prosecutor Judith E. Retchin asked him to let jurors know "that we are very close to the end because some of them look like they are very exasperated," Jackson apparently thought that was a good idea.

Bidding the jurors farewell for the evening, Jackson smiled and told them the trial would be over soon: " . . . You will have to spend one more . . . weekend in captivity."