Pope Benedict XVI is a head of state and the leader of more than a billion Roman Catholics worldwide. To Jeff Anderson, a lawyer who represents victims of sexual abuse by priests, he is also a potential legal witness.

Unlikely as it may seem, Anderson intends to demand the pope’s testimony in a sexual abuse case wending its way through court in Oregon.

“I don’t think I would require him to come to Oregon,” the attorney said in a recent interview. “I would go to him … and videotape and transcribe his testimony.” The Vatican, he said, should be treated “like any other corporation that is subject to the power of the American court system.”

Increasingly, the Vatican, an independent city-state headed by the pope, stands in the cross hairs of lawyers and investigators probing cases of sexual abuse in the Roman Catholic Church. The church is fighting back, maintaining both that it is not responsible for the actions of abusive priests and that it enjoys sovereign immunity from the U.S. legal system.

Several lawsuits filed in the United States have named the Vatican as a respondent, and attorneys in at least two cases are seeking a court order demanding testimony from the pope, among other top church officials. Police in Belgium last month raided church offices and opened tombs in a search for evidence in abuse cases, prompting Benedict to assail “the surprising and deplorable manner” in which the raids were carried out.

Anderson, who has become the Vatican’s leading legal antagonist in the clerical abuse cases, hailed a recent U.S. Supreme Court decision that dealt a procedural blow to the Vatican in its effort to shield itself from liability. Two days later, Anderson filed a new lawsuit in Los Angeles County Superior Court that targeted the Holy See.

“Look, I’ve been working with survivors, handling these cases for 25 years, and I knew that all roads in this scandal or crisis, whatever you want to call it, lead to Rome,” said Anderson, a Minneapolis attorney. “I feel really resolute about this, and feel that we now have a great deal of legal authority and traction at our feet and wind at our back, and we’ve never had that before when it comes to the Vatican.”

Perhaps, but Anderson and others still face a daunting task in stretching the arms of the U.S. justice system over the walls of the Holy See. The Vatican is in the unique position of being at once a highly complex religious organization and a sovereign nation, both of which make it difficult to penetrate legally.

The church’s defenders say that is as it should be. The Vatican, in their view, sets religious policy for the worldwide church but is not involved in day-to-day operations of its far-flung parishes and bears no legal responsibility for abusive priests.

“One of the fundamental issues in all of these cases is that there is a misunderstanding in the popular culture as to the organization of the Catholic Church and the autonomy of its various parts,” said Jeffrey S. Lena of Berkeley, the church’s American lawyer. “There are assumptions made daily in the press and elsewhere as to the allocation of authority amongst the various entities of the church.”

The idea of suing the pope or the Vatican over sexual abuse by priests in the United States, he said, makes no more sense than suing President Obama in a case of abuse by a public school teacher in California.

During a recent interview in his office in Rome, Father Federico Lombardi, the chief Vatican spokesman, was briefly speechless at the idea that the Vatican should turn over its files on sexual abuse cases to law enforcement authorities in the United States and elsewhere, as advocates for victims have demanded.

“I think this argument is rather unrealistic,” Lombardi finally said. “If I go to the United States government and ask them to give me all the documents they have, do you think this would be done?… No, I don’t see the grounds for such a request.”

Lena has laid out the church’s legal position in court filings in Oregon and Kentucky, where the Vatican has been named in lawsuits by victims who say they were abused by priests. Essentially, it rests on the Holy See’s claim of sovereign immunity, the same claim that could be used by any foreign government that is sued in a U.S. court.

Responding to a demand that the pope and his secretary of state testify in the Kentucky case, Lena said that both men are entitled to “absolute civil and criminal immunity” as heads of state and government. (The Vatican’s secretary of state, Cardinal Tarcisio Bertone, is the equivalent of a prime minister, he said.)

Lawyers for abuse victims have sought to breach that barrier by claiming that the Vatican falls under multiple exceptions to the sovereign immunity rule.

Courts have knocked down some of these arguments — for instance, the idea that the work of the church constitutes a “commercial activity” and not the regular, noncommercial work of a sovereign nation. But they have let the cases go forward under the “tortious act” exception, which says an organization can be liable if one of its employees committed wrongdoing (known in law as a “tort”) while carrying out his official duties.

Because the Vatican is a unique institution, some of these legal issues “are definitely uncharted territory,” said lawyer Michael Helfand, an expert on the intersection of law and religion who was recently named to the faculty at Pepperdine Law School. “This is something that courts have never really had to struggle with before.”

The Vatican has fought the latest legal onslaughts — and will continue to do so as the cases move toward trial — by claiming that priests and bishops in the United States are not employees of the Vatican but work instead for their local diocese or order.

Even archbishops, who are chosen directly by the pope, are not employees of the Holy See, Lena has contended, because their day-to-day work is not supervised by anyone in Rome.

“When an archbishop … serves in a position for decades without active supervision and with the equivalent of life tenure, it is a sign of independence, not employment,” he agued in a memo to the court in Kentucky.

But lawyers for the abuse victims contend that the Roman Catholic Church is a top-down hierarchy — in effect a very large corporation with the pope as chief executive. “Defendant Holy See has unqualified power over the Catholic Church, including each and every individual and section,” Anderson wrote in the Oregon lawsuit.

The courts in Oregon and Kentucky ultimately agreed that it wasn’t a stretch to say Catholic bishops and priests were employees of the Vatican. And when the church appealed the 9th District Circuit Court of Appeals ruling in the Oregon case, the Supreme Court sent the case back, refusing to hear it.

Lena said the high court’s refusal to hear his appeal was a largely technical setback that has no wider application.

Anderson, however, claimed it as a major victory, saying the decision opens the door to bringing the Vatican to justice for failing to stop priests from abusing children.

His next step, he said, will be to demand records and depositions from Vatican officials, including testimony from the pope himself — a prospect that, Anderson admitted, would not happen “voluntarily” or “willingly.”

That is an understatement, but Anderson is not listening to naysayers. “The so-called sovereign immunity doctrine that they have used as a barrier has now been crumbled and cracked,” he said. “They are still sovereign, but they are not immune.”

mitchell.landsberg@latimes.com