The judge's "five-minute rule" had expired five times over, but the potential juror showed no sign of slowing down. The mayor was just a step away, in front of her; reporters strained to write down every word. Not every day does a person find that kind of soapbox.

Her name was Price (the first name was inaudible from the galleries) and she lacked for nothing at all in the opinion department. Every answer was a discourse. Every discourse had a footnote. The judge, by turns exasperated and amused, called her "a loose cannon" on the stand.

But by the end of the afternoon yesterday, Price was qualified as a juror in the drug and perjury trial of D.C. Mayor Marion Barry, along with 11 other members of her panel. How and why that happened has much to say about the methods and limits of "voir dire" in choosing a jury of Barry's peers.

Many potential jurors have been nervous in the vaulted marble courtroom of U.S. District Judge Thomas Penfield Jackson. Price was having none of that, and she did not take long to prove it.

Jackson made his standard opening: Was she aware of the publicity in the Barry case?

Her awareness was "superficial," Price replied. She did not like to read the papers, she said. The Washington Post in particular, she said, "is a very poor citizen of this community," and she preferred not "to invest in it as a reader." The news media in general are more entertainment than news, she said, "and in terms of entertainment I prefer 'Dallas' and 'Falcon Crest.' "

Several minutes later she concluded her answer. "I suppose, to be perfectly honest, I should footnote a little bit here . . . . What I am interested in as a human being is helping people I can help, as the saying goes, thinking globally and acting locally."

Voluble and articulate, Price spent the next 30 minutes unburdening herself of every thought and philosophy that came to her. Jackson and Assistant U.S. Attorney Richard W. Roberts, who questioned her, learned the following solicited and unsolicited facts.

Price stands 4 feet 11 3/4 inches. She still has a Dukakis bumper sticker on her car. She thinks law enforcement officials are "courageous people doing honorable work." She thinks politicians are "honorable people doing courageous work." The mayor, as far as she is concerned, "is just another Adam." On the question of lying under oath, she believes that "truth is as negotiable as integrity allows." She is sure she has been the victim of prejudice, "because in instances of applying for a job, having sent in my resume, having talked on the telephone, I'm perfect for the job, but when I show up, no."

Roberts spent an unusually long time in questioning Price, and the judge allowed the interview to go on. Both appeared to be wondering whether she would disqualify herself from further service by revealing that she was biased in the case.

She did not. When it came time for the defense to question her, lawyer Robert W. Mance asked nothing.

At the end of the day, as on previous days, Jackson asked the lawyers whether they wished to strike any potential juror "for cause." Roberts stood up and challenged Price, identifying her by her number, 209.

"I knew we were coming to this," the judge replied, grinning broadly.

"I don't want to stand in judgment of how other people choose to conduct themselves," Roberts said, but he worried whether Price could focus on the proceedings.

Jackson worried too, but he said he was at a loss for any legal authority "which would permit me to conclude that a juror's affect {demeanor} was sufficiently unorthodox to disqualify him or her from service."

Mance, representing Barry, argued strongly for keeping Price in the jury pool. Jackson twice inquired if he was sure.

"I hope you're viewing her advisedly, Mr. Mance," he said. "I think she may be a loose cannon . . . . Her answers . . . are sufficient, I would think, to give pause to either side."

A loose cannon, according to some experienced trial lawyers, may be exactly what the mayor is looking for on his jury. In particularly difficult cases, the experts said, some lawyers will aim their hopes at a hung jury. Such lawyers, the experts said, look for strong, independent personalities capable of resisting pressure from jurors who may be leaning toward conviction.

Prosecutors still have recourse if they feel strongly about keeping Price out of the jury box. Each side will have an undisclosed number of peremptory strikes when they make final cuts Monday morning, and the prosecution may remove her then without having to offer a legal reason.

Until Monday, interviews will continue from among the randomly selected pool of 250 citizens. Yesterday, Jackson conducted 15 interviews in open court, of which three resulted in dismissals. He excused four jurors from further service on the basis of their written questionnaires alone.

All told, 113 prospective jurors have been examined in seven days, of whom 70 have been found qualified to hear evidence in the case.