Prosecution and defense homed in on a final jury pool yesterday in the drug and perjury trial of Mayor Marion Barry.

At noon today, according to a timetable set by U.S. District Judge Thomas Penfield Jackson, the court will stop qualifying potential jurors to hear the mayor's case. So far, 142 panelists have been examined from a randomly selected pool of 250 D.C. residents, and Jackson has qualified 83 of them to hear evidence. Lawyers for each side will make peremptory cuts -- for any reason they like -- Monday morning, and Jackson will seat 12 jurors and six alternates.

Barry's announcement Wednesday that he won't seek another term was a persistent theme on the ninth day of jury selection. Several potential jurors acknowledged seeing or hearing news accounts of Barry's plans, or hearing about them from other people.

Assistant U.S. Attorneys Richard W. Roberts and Judith E. Retchin probed carefully for signs that the prospective jurors would be less inclined to convict a man whose days in public office were near an end. R. Kenneth Mundy, the mayor's attorney, sought to learn whether any panelists would construe Barry's announcement as a sign that he is guilty.

None of the 15 potential jurors examined yesterday said the announcement would affect them.

"If their answers to my questions are true barometers," Mundy said in an interview during the noon recess, "they are putting it out of their minds."

The potential jurors are under orders to avoid news accounts "of the case or of these proceedings." It is unclear whether those orders applied to the mayor's speech. Beginning Monday afternoon, deputy U.S. marshals will shield the sequestered jurors from any out-of-court reference to Barry or the charges against him.

For the first time in nearly two weeks, proceedings were briefly disrupted yesterday. Just as Jackson called a luncheon recess, a man stood up in the back row, held out his arm and declared, "Excuse me, I'm from San Francisco and this is cocaine and marijuana given to me by the federal government."

U.S. marshals immediately arrested the man, who was wearing a tuxedo, a neck brace, a yellow rain slicker and dark sunglasses. The man, identified as Sherman Hill, 48, of San Francisco, was charged with possession of marijuana and cocaine, marshals said, after D.C. police tested the substances Hill waved in the courtroom.

Jackson excused eight of the 15 panelists interviewed yesterday, six of them on his own initiative in open court. As he did Wednesday, however, he called a bench conference so that the lawyers for each side could request additional dismissals from the panel in private. Jackson also placed a sealing order on transcripts of those discussions.

Jackson said in a brief interview Wednesday that he did not want prospective jurors to know when either side had sought to exclude them.

Late yesterday afternoon, The Washington Post and ABC News filed a motion with the court seeking access to the sealed transcripts and future arguments over the composition of the jury. Jackson made no response by evening.

From the context of earlier proceedings, it was clear that both of the prospective jurors disqualified during yesterday's bench conference were removed at the prosecution's request.

Carl Wallace, juror number 280, initially had professed no opinion of the case, but under questioning by Roberts he expressed strong opposition to the FBI "sting" of Barry at the Vista Hotel. It was an invasion of privacy, he said, "and what's more, it's a waste of money."

Wallace appeared to be on the verge of rehabilitation when he said he could obey the court's instructions to disregard those feelings. But Roberts, who worked methodically to disqualify him, then elicited from Wallace a vow that he would insist "without any question" on discussing the unfairness of the sting during deliberations. Jackson excused Wallace.

The other prospective juror dismissed after the bench conference was a man named Vincent who appeared to be in his forties. His full name was not audible from the gallery. Vincent, whose written questionnaire said officials "went out of their way to find something wrong with the way {Barry} ran the government and his private life," said from the witness stand yesterday that the prosecution was politically and racially motivated.

Mundy tried to salvage him from dismissal. After an extensive line of leading questions, Vincent told Mundy he could "probably" set his personal views aside.

"Do you understand that you would not only be violating your duty to this court but your oath to your God if you failed to do that?" Mundy asked.

"Yes," Vincent replied.

Jackson excused him anyway.

Staff writer Michael York contributed to this report.