Former Allegheny County Coroner Dr. Cyril Wecht has participated in thousands of criminal cases over his lengthy career as a forensic pathologist.

Because of that, his attorneys argue, he has likely made some enemies over the years.

And, they continue, there is no way their client can get a fair trial if he is not permitted to know the identities of the potential jurors who will hear his criminal case next month in federal court.

Last week, U.S. District Judge Arthur J. Schwab ruled that the jury to be empaneled in the case will be anonymous. No one in the court will be permitted to know the jurors' names or addresses.

Judge Schwab gave no reason for his decision, and neither side had requested an anonymous panel.

The defense strenuously opposes the decision, claiming that it will deny Dr. Wecht a fair trial. Several media outlets have also objected to an anonymous jury and filed their own petition on the matter yesterday.

On Dr. Wecht's behalf, defense attorney Jerry McDevitt wrote in his 24-page brief that it is essential his client know the names of potential jurors in his case.

Since Dr. Wecht frequently serves as an expert witness, there likely are "many individuals that may harbor ill will toward him for his involvement in the prosecution and incarceration of family members or friends," the defense wrote. Without names, defense attorneys will have no way to guard against any such person getting on the panel.

In their filings, the defense also notes that their client's son, David Wecht, is a family court judge in the Allegheny County Court of Common Pleas. In such a position, they said, he likely has made enemies, as well. They had planned to share potential juror names with him to review, but under part of Judge Schwab's order, juror questionnaires will not be permitted outside of the courthouse.

"There is simply no basis in this matter to believe that Dr. Wecht or his counsel are a threat to jurors, and the mere suggestion that there is a need for secrecy to protect jurors is extremely prejudicial and unfair," Mr. McDevitt wrote. "He and his family are pillars of the community, and it is potentially unfair to treat him as if he were some mobster."

Typically, anonymous juries are used in cases where the defendant may pose a threat to jurors, or to ensure their safety.

There have been only two cases in the Western District of Pennsylvania in which an anonymous jury has been used in the past. The first was in the summer 2005 retrial of infamous cocaine dealer Terrance Cole. The most recent case was in October during the death penalty trial of Jelani Solomon, who was convicted of having the father of a witness against him killed.

Anonymous juries are occasionally used in cases involving public officials, but it is rare, said Mary R. Rose, an assistant professor of sociology and law at the University of Texas at Austin.

In two trials in Louisiana involving former Gov. Edwin Edwards in 2000, both juries were anonymous.

One of the most important things to consider, Ms. Rose said, is the effect anonymity may have on the jurors.

"Anonymity takes away an element of responsibility," she said. "People perceive themselves as jurors differently when the responsibility of being named is removed."

Indeed, that is part of the argument raised by Dr. Wecht's defense.

"Witnesses, and in this case, jurors are more likely to answer more truthfully without embellishment and/or without withholding information if they are aware that their responses may be subject to public scrutiny," Mr. McDevitt wrote.

In the meantime, attorneys for the Pittsburgh Post-Gazette, Tribune-Review Publishing Co. and WPXI Inc. filed their own objections yesterday to the use of an anonymous jury in the Wecht case. They argued that it violates the public's constitutional right to access and impedes the public right to scrutinize proceedings.

In an 18-page filing, the media identified a number of reasons cited by the U.S. Supreme Court why criminal proceedings should be held publicly.

They include that there is an appearance of fairness; that perjury is discouraged; and that it helps to ensure public confidence in the system.

An anonymous jury, they wrote, takes away from all those things.

The government has until Tuesday to file a response to the defense motion.