The nation's Roman Catholic bishops will meet here this week to vote on changes requested by the Vatican in their sexual abuse policy -- changes that church lawyers and public prosecutors say could produce serious conflicts between the church's internal legal code and U.S. civil law.

Under the revised policy, church tribunals would gather and weigh evidence against priests who might also face criminal prosecution in civil courts. Church, or canon, law requires the tribunals to meet behind closed doors and to keep their records secret. Prosecutors could subpoena the records, but the church might resist on First Amendment grounds. Moreover, some of the tribunals could be held in Rome, beyond the reach of U.S. courts, experts said.

"We have a great deal of concern about any proceedings being held outside a court of law, particularly in cases of child sexual abuse," said David Procopio, spokesman for the Suffolk County (Mass.) District Attorney's Office, which has jurisdiction over Boston. "We believe the only proper finder of fact is a court of law, and that's where these issues should be decided."

The bishops' four-day meeting, which begins Monday, is the second time in five months that leaders of the U.S. Catholic Church have grappled publicly -- under the glare of TV lights and amid the din of protests -- with the scandal that has deluged many dioceses in lawsuits.

At an emotional two-day session in Dallas in June, victims described their childhood encounters with predatory priests. Prominent Catholic laypeople accused the bishops of arrogance. And Wilton D. Gregory, the bishop of Belleville, Ill., and president of the U.S. Conference of Catholic Bishops, told his peers that "We are the ones" who let the faithful down.

Chastened, the bishops voted 239 to 13 to require the removal from public ministry of any priest who has abused a child, even in a single known incident decades ago. But the Vatican refused last month to approve that so-called zero-tolerance policy, saying it was "difficult to reconcile" with the due process protections afforded to priests by worldwide canon law.

The proposed revisions, drafted by four U.S. bishops and four senior Vatican officials, spell out the steps dioceses are supposed to take when they receive an abuse complaint. If the bishops endorse the new text, it will be resubmitted for Vatican approval, which would make it binding.

Sister Mary Ann Walsh, a spokeswoman for the bishops conference, said there are no plans this week to repeat the theatrics of Dallas -- no scheduled opportunities for victims or angry laypeople to dress down the bishops. But protesters are organizing news conferences, a candlelight vigil and the release of a database of more than 600 accused priests, all to underscore what they view as backsliding from zero tolerance.

Among the proposed changes to the Dallas "norms" are:

* Tribunals. Bishops could continue to place suspected abusers on temporary leave. But only a tribunal of fellow priests could permanently bar an accused child molester from public ministry. Because of a shortage of qualified judges and lawyers, the bishops may decide to set up regional courts to conduct these internal church trials, according to Cardinal Francis George of Chicago.

* Reporting. The Dallas policy required church officials to report every sexual abuse allegation involving a current minor to civil authorities. The revised norms require dioceses only to "comply with all applicable civil laws," which in nearly half the states do not require clergy members to report such allegations.

* Statute of limitations. The Dallas policy appeared to ignore canon law's statute of limitations on sexual abuse cases, which is 10 years from the victim's 18th birthday. The revisions clarify that the time limit is in force, though bishops could ask the Vatican to lift it in individual cases.

* Lay boards. In Dallas, the bishops required every diocese to establish a review board of laypeople to help evaluate sex abuse allegations. The revisions specify that these boards are "confidential" bodies with purely advisory powers and are to consist of at least five Catholics in good standing with the church.

* Definition. The new text would define sexual abuse as an "external, objectively grave violation of the Sixth Commandment," the biblical prohibition against adultery. Like the Dallas policy, however, it would state that sexual abuse need not involve "force, physical contact or a discernible harmful impact."

* Transfers. The revisions would flatly prohibit transferring a known sexual abuser to a new ministerial assignment in another diocese, which was implicit but unstated in the Dallas norms.

Victims groups say these changes reduce the power of the laity and provide no mechanism to hold bishops accountable.

Gregory, who has traveled to Rome three times this year to confer on the sexual abuse issue, denies that the Vatican is forcing the bishops to soften their disciplinary policy. Rather, he said in a Nov. 1 statement, the Holy See has shown "legitimate concern for the rights of the accused" while confirming the core promise made in Dallas: that for "even a single act" of sexual abuse, a priest "will be removed permanently."

The revisions also include a fail-safe clause that appears to give individual bishops the power to get rid of a suspected abuser no matter what a church tribunal decides. "At all times," it says, a bishop has the "executive power of governance" to remove a cleric.

The Rev. Ladislas M. Orsy, a professor of canon law at Georgetown University, said the fail-safe clause is one of several points the bishops may need to clarify this week. "The more I read these norms, the more I get confused," he said.

Catholic Church tribunals in the United States have dealt mainly with requests for marriage annulments. But the centuries-old system of canon law also sets out detailed procedures for tribunals to determine the innocence or guilt of people accused of crimes under church law, such as embezzlement, violations of the secrecy of the confessional or sexual misconduct.

A church prosecutor, known as a promoter of justice, brings a kind of indictment, called a libelus. If the defendant is a priest, the panel of at least three judges also must be clergymen -- though Chicago's Cardinal Francis George suggested that U.S. bishops could apply to the Vatican for permission to include a layperson as a judge to increase public confidence.

As in civil courts, the defendant has a right to an attorney and cannot be compelled to incriminate himself. Both the promoter of justice and the defendant's legal advocate may call witnesses. And the church prosecutor bears the burden of proving guilt.

Unlike a civil trial, however, the judges in a church tribunal typically do the questioning. Hearsay is admissible as evidence, and the proceeding is closed to the public.

A papal directive last year also stipulated that a Vatican department, the Congregation for the Doctrine of the Faith, will decide in sexual abuse cases whether the tribunal should be held in the United States or in Rome.

Some public prosecutors who have handled clergy sexual abuse cases said they would encourage the Catholic Church to conduct its own investigations and trials, but only after the local district attorney has looked into a particular case and decided not to prosecute.

"Whether it's the Catholic Church or the XYZ Corporation, any employer that suspects criminal activity by an employee ought to make a personnel inquiry, and might even be negligent if they do not," said New Hampshire Attorney General Philip T. McLaughlin.

"But if we have a pending criminal prosecution, they could not go out and question a potential victim, for example, because in the state of New Hampshire we would be very likely to construe that as witness tampering," McLaughlin said.

Laurence E. Hardoon, a former Massachusetts prosecutor who represents plaintiffs in civil lawsuits against the church, noted that civil lawsuits often are frozen until related prosecutions are completed. Similarly, he said, the church should defer to the criminal courts. "As long as they do that, I don't see a down side to these tribunals," he said.

Other prosecutors foresaw deeper problems.

"All the people involved in these cases from our end -- the prosecutors, our victim's advocates, forensic interviewers, even the interpreters -- they all have specialized training in the unique nature of these crimes, and that training is critical to making sure the interviews elicit the truth and do so in a way that does not cause further trauma to the victim," said Procopio, the spokesman for Suffolk County District Attorney Daniel Conley. "In these church tribunals, we would be very concerned as to whether the people interviewing the victims or the witnesses would have proper training."

Milwaukee District Attorney E. Michael McCann said church tribunals could "raise very interesting First Amendment questions" because prosecutors probably would subpoena the records of any cases that fell within the statute of limitations for prosecution in civil courts. Statements made by an accused priest before a tribunal might not be admissible as evidence, but statements by witnesses probably would be, he said.

"Historically, the seal of confession has been respected. But persons who are witnesses -- I don't see how that's protected at all," he said. "A prosecutor probably could get access to that."

The Catholic Church, however, would not hand over its records voluntarily, said the Rev. Patrick Lagges, the top canon lawyer for the Chicago archdiocese.

"We'd certainly have to abide by whatever the civil courts have ordered us to do," Lagges said. "But the tribunal would be about the status of the priest within the church, and traditionally civil courts have not gotten involved in those sorts of things."

The Rev. Kevin McKenna, a priest in Rochester, N.Y., who is a past president of the Canon Law Society of America, said he believes that "goodwill and cooperation" could allow the two legal systems to coexist without friction. But given the distrust shown by law enforcement officials toward bishops in several jurisdictions this year, he acknowledged, it is possible that some prosecutors could object to the church tribunals, or even charge church officials with obstructing justice.

"We're in some new territory here," McKenna said. "There are a lot of questions now being raised about the interaction of canon law and civil law, and no one has the definitive answers."

Bishop Wilton D. Gregory, center, said the Vatican showed "legitimate concern for the rights of the accused." Bishops vote on the sex abuse policy last summer. They meet here this week.