Washington — The Justice Department has launched an investigation into alleged sexual abuse of children by Catholic clergy across the state of Pennsylvania — a major escalation of government scrutiny of the church long sought by victims of pedophile priests.

The decision to launch such a probe, even one limited to a single state, is noteworthy because the federal government has long shied away from tackling allegations that the church spent decades hiding the extent of the sexual abuse problem among its priests, and allowing pedophiles to continue to work and live undetected in communities.

"This is just a breathtaking, stunning and very welcome development," said Michael Dolce, a lawyer who represents victims of sexual abuse.

The U.S. attorney's office in Philadelphia began issuing subpoenas recently, according to one person familiar with the matter. A spokeswoman for the U.S. Attorney, William McSwain, declined to comment, though church officials around the state confirmed having received subpoenas.

The subpoenas seek years of internal church records, including any evidence of church personnel taking children across state lines for purposes of sexual abuse, any evidence of personnel sending sexual material about children electronically and any evidence that church officials reassigned suspected predators or used church resources to try to further or conceal such conduct, according to a person familiar with the matter.

The investigation was sparked after a state grand jury issued a scathing report in August, finding that more than 300 Catholic priests in Pennsylvania had sexually abused children over seven decades, protected by a hierarchy of church leaders who covered it up.

The lengthy report identified about 1,000 children who were victims but concluded there were probably thousands more.

"Priests were raping little boys and girls, and the men of God who were responsible for them not only did nothing; they hid it all. For decades," the grand jury wrote in its report, which prompted victims across the country to come forward and new probes in other states.

The report was the product of an 18-month investigation into six of the state's dioceses — Allentown, Erie, Greensburg, Harrisburg, Pittsburgh and Scranton — and follows other state grand jury reports that revealed abuse and coverups in two other dioceses.

Jerry Zufelt, a spokesman for the Diocese of Greensburg, said the subpoena "is no surprise considering the horrific misconduct detailed in the statewide grand jury report. Survivors, parishioners and the public want to see proof that every diocese has taken sweeping, decisive and impactful action to make children safer. We see this as another opportunity for the Diocese of Greensburg to be transparent."

The decision to launch the federal investigation was made by prosecutors in Philadelphia, not senior Justice Department officials in Washington, according to the person familiar with the matter. News of the investigation was first reported by The Associated Press.

Marci Hamilton, a constitutional law expert at the University of Pennsylvania and founder of an advocacy group fighting child abuse said it appears the federal probe is focused on possible violations of child pornography laws and the Mann Act, which bars crossing state lines for sex.

Hamilton, who advises survivors of clergy abuse and groups that advocate for them, said Pennsylvania is a prime place for such a probe because of the grand jury report.

The report "persuaded a lot of politicians that it's politically safe to investigate the church. Thirteen states are investigating. The federal government is finally doing something. The federal government has been conspicuously absent from this discussion," she said. "I think the logjam is breaking by those in power to look deeply into this issue."

Hamilton predicted the church in Pennsylvania will fight.

Democratic state Rep. Mark Rozzi, who was abused by a priest when he was a child, said even though the state has just been through a long grand jury probe, he thinks the federal investigation is a "better opportunity to go after the Vatican and hold them responsible. It's a better opportunity for victims."

Rozzi said he hopes that through the federal investigation in Pennsylvania and the state-level investigations now underway across the country, "we can find out what really happened and get all the documents, and gain as much as we can from this, learn from it and make sure it never happens again. We must make sure these victims are compensated for the suffering they are going through."

Since the Catholic clergy's sexual abuse scandal became a nationwide story in 2002, the Justice Department largely has stayed away, leaving the issue to local prosecutors to pursue whatever cases they could under their states' statutes of limitations. The church also has struck a series of financial settlements with those who have pursued lawsuits seeking damages.

In Allentown, the diocese said in a statement it "will cooperate fully with the request, just as it cooperated fully with the information requests related to the statewide grand jury. The Diocese sees itself as a partner with law enforcement in its goal to eliminate the abuse of minors wherever it may occur in society."

The move from the Justice Department comes as the Pennsylvania state legislature has balked at taking action on the issue of clergy abuse in the state.

The grand jury that released its report in August made recommendations for legislators, including extending the criminal statute of limitations for sexual abuse of children and opening a two-year window for victims to sue their abusers. Under current state law, the Pennsylvania attorney general's office was only able to charge two of the 301 priests named in the report; the second pleaded guilty this week.

The state House of Representatives passed a bill that would have enacted the grand jury's recommendations, but on the final day scheduled for voting on Wednesday, the Senate did not pass the bill.

The state attorney general's office has strongly urged the Senate to pass a bill.

"We're fighting the fight in the Pennsylvania legislature. That led to a standstill last night, but it's not over," attorney general's office spokesman Joe Grace said on Thursday. He urged Senate leaders to call legislators back to Harrisburg for another day of voting. "The attorney general made clear that we're not going away. Neither are the victims."

Pennsylvania is believed to have conducted more investigations of institutional child sex abuse than any other state, but there is no full accounting of abuse in the Catholic Church in the United States.

Peter Isely, a longtime advocate for victims of sexual abuse, said groups have long been pressing the U.S. government for a national investigation of child sex abuse, especially in the Catholic Church. Isely, who was abused and is a spokesman for the global group Ending Clergy Abuse, said that a five-year inquiry in Australia is "the gold standard," but that other nations, including Canada, Germany and Ireland, have conducted national forensic reviews.

"Imagine if they did what was done in Pennsylvania but nationwide," he said, arguing that the problem needs to be solved by the Vatican.

In America, the most far-reaching study was one conducted in 2004 by the John Jay College of Criminal Justice at the City University of New York. It reviewed abuse by priests and deacons from 1950 until 2002 to define the scope and nature of the problem.

Worldwide, national law enforcement agencies are targeting abuse within the church. In Chile, prosecutors and police this summer raided church offices, confiscating documents and looking for evidence of crimes that went unreported to police.