There are no locks on the gates of the black, wrought-iron fence that surrounds the Loudoun County Circuit Courthouse in Leesburg. People are free to come and go as they please.

Nonetheless, for the last three and a half days, dozens of citizens have been imprisoned on the grassy yard in front of the red brick courthouse, built in 1894. They are held captive by their own intense fascination with the outcome of the dramatic trial of William (Bull) Evans-Smith, charged with murdering his wife of 43 years, Barbara, last April.

"It's just like the last page of a mystery. You can't go away," said Mimi Tandler of McLean.

No denouement to the mystery came yesterday, as the jury of eight men and four women failed to reach a verdict after about 22 hours of deliberation.

The deliberations began Monday, following 10 days of testimony from nearly 100 witnesses that often delved into intimate details of the lives of the American University official and his wife.

The case has entranced the historic, rural town, drawing to its bustling center numerous spectators, many of whom knew the couple personally and who have waited each day at the courthouse hoping to hear the verdict.

The lengthy period of anticipation has been wearying for many. "It's sometimes easier trying a case than waiting for a verdict," said defense lawyer Blair D. Howard after the jury left yesterday.

Business is booming at the Leesburg Restaurant across the street from the courthouse. Each day during the deliberations, owner Farris Sadak quizzes lunching spectators: "Is today the day?"

A hint that the case was near resolution came yesterday when Judge Carleton Penn asked the jury whether they were making progress, and the members nodded to indicate that they were.

Many in the gallery of spectators that has stayed with the trial throughout did not seem bothered by the additional night's wait.

"We've come here and really had a social life," said Louise McLamara of Leesburg, one of the veterans of the audience, many of whom have become friends during the wait for the verdict.

"It's the mystery aspect of it. Did he do it or didn't he?" Tandler said.

Indeed, Tandler, a former Texas journalist, began attending the trial with the intention of researching a mystery novel she planned to write. Now she plans to write a nonfiction account of the case.

"I just got hooked on the trial. It's got the great characters. It's got the setting. . . . All it needs is a thunderstorm and a butler. . . . Everything about it just beats fiction altogether," Tandler said.

The local weekly newspaper, the Loudoun Times-Mirror, has reported record sales of each edition since the trial began, according to reporter Claudia Smith. And the courthouse lawn is strewn with the equipment of camera crews from Washington television stations.

But those who have stayed with the trial said news media accounts are no substitute for being there.

"You can learn a lot just from watching their faces," Sarah McLamara said of the many characters in the case. Tandler agreed, saying she has been especially intrigued by the erect, balding, neatly groomed Evans-Smith. "He looks like somebody next door," she said. "He doesn't look like somebody who should be on trial for murder."

Like others following the trial, Tandler said she feels empathy with Evans-Smith's three daughters, who have frequently attended the trial, sometimes embracing their father at the end of the day.

"Guilty or innocent, it's got to be an ordeal," she said.

Many spectators said some of the people most interested in the verdict haven't been in attendance during the trial at all: members of Loudoun's elite horse set who knew Barbara Evans-Smith, but who believe it would be indiscreet to attend the trial.

"I've been getting calls from people every day asking 'What happened?' " said one person, who asked not to be named.

Joan Rokus of Leesburg, said that many of the locals are especially interested in the case because of its revelations that Evans-Smith carried on an extramarital affair for 11 years. "There are many women who are very anxious to see how this concludes," she said.

The jurors, who will return at 9:30 a.m. today, have been instructed to find Evans-Smith guilty of first- or second-degree murder or not guilty. The respective sentences, to be decided by the jury under Virginia law, are 20 years to life and five to 20 years.