The judge in the bribery trial of Alexandria prosecutor William L. Cowhig yesterday summoned a Washington Post reporter to explain an apparent violation of the judge's order forbidding interviews with witnesses in the courthouse during the trial.

The reporter, Stephanie Mansfield, took the witness stand outside the presence of the jury to tell Circuit Court Judge Percy Thornton Jr. that she had sought to question Alexandria police detective Cecil Hensley on matters unrelated to the Cowhig trial.

Mansfield, 28, also told Thornton under oath that she was not assigned to cover the trial and that she had been unaware of his order. Thornton has prohibited interviews with witnesses before their testimony, interviews with any Cowhig trial participants in the courthouse hallways and the presence of cameras and recording devices in the court building.

The incident was the first to arise since Thornton issued his oral order to reporters at the start of the trial on Tuesday, an order that he repeated before the start of proceedings Wednesday. Thornton said he was making the ruling to ensure a "fair and impartial trial... and an untainted jury" for Cowhig.

Cowhig is accused of asking for and receiving $32,000 in bribes from Dirgham Salahi, director of the Montessori School of Alexandria Inc., a sponsor of lucrative bingo games in the city.

"Can you explain why you chose this time" to interview Hensley, Thornton said in a loud voice to Mansfield, who sat a few feet away in the witness box.

Mansfield, a Virginia staff reporter for The Post, responded that her previous attempts to contact Hensley by phone had failed, and that she had been in the building on other matters when she saw him outside the courtroom. "I'm sorry if I did anything wrong," she told the judge during the unusual 20-minute hearing.

Under an agreement worked out between Thornton and Kevin Baine, an attorney representing the paper, Mansfield was not asked by Thornton about the nature of the questions she had wanted to ask the detective.

Hensley testified that on Wednesday morning Mansfield aproached him in the courthouse hallway. When he told her about Thornton's ruling, according to Hensley, Manstield said, "You mean you are refusing to talk to me," and then walked away when he said, "Yes."

Virginia state police investigator Thomas Dever corroborated Hensley's testimony.

"What you do is create a cloud" over the impartiality of witnesses by attempting to interview them in the courthouse, Thornton told Mansfield. "Put it (the interview) off, do something else -- outside the courthouse is something else," he said.

Thornton denied a request by Baine for a written copy of his rules, stating that reporters "understand the English language." Thornton then stated his rules again.

Thornton, who recently criticized the press for seeking what he called "sensationalism" instead of facts, told the jury at the end of the day to avoid looking at courtroom artists' sketches on television, since that might taint their objectivity.

Thornton said that Wednesday evening he had seen an artist's rendering of the courtroom participants, and "I came out looking like a walrus minus the tusks."