The camera flash went off in front of 14 men and women assembled in a D.C. Superior Court jury box. Some of them had noticed flashes earlier, too, when they were gathered outside Judge Lynn Leibovitz’s courtroom waiting to be called for jury service.

So when it was time to be sworn in and listen to opening statements in a trial for a 2008 killing, the jurors instead told the judge they were afraid for their safety. The concern, they said, was that friends or relatives of the defendants might have taken the pictures to signal that the jurors were being watched — and could be found, and perhaps harmed, if they came back with guilty verdicts.

Leibovitz immediately dismissed the jury and ordered a new one.

“I take very seriously the concerns you raised,” she said, according to a court transcript. “And I want you to know that we take your security very seriously.”

The incident last month was the first that many court employees could recall of a judge dismissing a jury because of a perceived threat. It has raised new concerns about jury safety and intimidation in Superior Court. And it has left authorities facing the question of whether they must expand the way they prevent such threats in the future.

Photography inside the courthouse, unless at celebrations such as weddings or adoptions, is prohibited. But the proliferation of camera phones in recent years has made that rule difficult to enforce. The volume of visitors at the courthouse each day makes it impractical to collect phones at the front entrance. Instead, officials monitor phone use in courtrooms to ensure that pictures of witnesses, defendants and jurors aren’t snapped.

Marshals put less effort into monitoring phone use in the hallways. But that could change as a result of the March 26 incident in and outside of Leibovitz’s courtroom.

After Leibovitz dismissed the 12 jurors and two alternates, she told the room that no one could use phones in the hallway. She also ordered court security to set up a table in the corridor to confiscate cellphones from anyone entering.

“You will have to make your phone calls elsewhere in the courthouse at the risk of having your phone or electronics confiscated and being removed from the building,” she said, according to the transcript.

Less clear is whether building-wide changes are in store. Court spokeswoman Leah Gurowitz declined to answer that question, saying the court does not comment on specific cases. Cole Barnhart, a spokesman for the court’s marshals, said his officers have not been notified of any changes to the current policy on electronic devices. Bill Miller, a spokesman for the U.S. Attorney’s Office, said prosecutors were working with the marshals to investigate the incident, but no charges have been filed.

Threats or perceived threats against jurors aren’t unusual, said several attorneys who handle cases in the courthouse. But incidents are generally isolated to one juror in the hallway or at a nearby restaurant during lunch. In those cases, the juror typically alerts the courtroom clerk, who informs the judge. The judge then questions the juror about the details to determine whether the juror should be excused, lawyers said.

Some judges have implemented their own security measures to reduce threats to juries. In some courtrooms, audience members are not allowed to sit in the first row or two behind a jury, to discourage interaction.

The defendants in the March 26 case, Robert Walker and Rodney White, both 24, were charged with first-degree murder in the shooting of Jasmine McCray, 23, at the Benning Park apartments in Southeast Washington.

According to the transcript, White’s attorney, Teresa Kleiman, said her client’s cousin took the picture, but it was an accident. Kleiman said the woman was fixing her hair while looking at her reflection in the phone, and the flash went off. Marshals removed White’s cousin, and Leibovitz said she could not return. The identity of the person who took the hallway photo remains under investigation.

The pictures raised several concerns. The defense attorneys said the jurors might be unable to listen to the evidence and render a fair verdict out of concern for their safety.

“I don't know how we can undo the prejudice from it,” said Jennifer Wicks, Walker’s court-
appointed attorney.

With a new jury, the trial began two days later. After a week of testimony and about a day of deliberations, Walker and White were convicted of murder and other charges.

The jury sent a note to Leibovitz announcing that it had reached a verdict, and it also sent a note expressing concerns about safety. As a result, marshals escorted the 12 jurors to the nearest Metro station.