PHILADELPHIA >> The U.S. Justice Department has opened an investigation of child sexual abuse inside the Roman Catholic Church in Pennsylvania, using subpoenas to demand confidential files and testimony from church leaders, according to two people familiar with the probe.

The subpoenas, served last week, follow a scathing state grand jury report over the summer that found that 301 “predator priests” in Pennsylvania had molested more than 1,000 children over seven decades and that church leaders had covered up for the offenders.

Now federal prosecutors are bringing the Justice Department’s considerable resources to bear, according to two people who were not authorized to discuss the investigation publicly and spoke to The Associated Press on condition of anonymity.

“It’s groundbreaking if we’re going to see one of the U.S. attorneys pursuing the Catholic cases,” said Marci Hamilton, a University of Pennsylvania professor and chief executive of Child USA, a nonprofit think tank focused on preventing child abuse. “The federal government has so far been utterly silent on the Catholic cases.”

At least seven the state’s eight Roman Catholic dioceses — Philadelphia, Pittsburgh, Scranton, Erie, Greensburg, Allentown and Harrisburg — acknowledged receiving subpoenas and said they would cooperate or were working with Justice Department officials.

“This subpoena is no surprise considering the horrific misconduct detailed in the statewide grand jury report,” the Greensburg Diocese said in a statement. “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.”

There was no indication the Justice Department is planning a more ambitious and expensive investigation of clergy abuse nationwide.

U.S. Attorney William McSwain of Philadelphia, who issued the subpoenas, wants to know if priests, bishops, seminarians or others committed any federal crimes.

McSwain, appointed by President Donald Trump earlier this year, asked for certain church leaders to testify before a federal grand jury in Philadelphia, though it could be months before that happens because of the time it takes to review the requested documents.

McSwain also demanded bishops turn over any evidence that anyone in their ranks took children across state lines for illicit purposes; sent sexual images or messages via phone or computer; instructed anyone not to contact police; reassigned suspected predators; or used money or other assets as part of the scandal.

The subpoenas seek documents stored in “Secret Archives,” ”Historical Archives” or “Confidential Files,” and records related to the dioceses’ organizational charts, finances, insurance coverage, clergy assignments and treatment of priests, according to the people who spoke to the AP.

A representative for McSwain declined to comment, as did a Justice Department spokeswoman.

“I’m thrilled at hearing this information. We have the full weight and attention of the United States federal government investigating the Roman Catholic Church,” said Shaun Dougherty, 48, of Johnstown, who told authorities he was molested by a priest as a boy in the Altoona-Johnstown Diocese.

Two Eastern Catholic dioceses in Pennsylvania — the Ukrainian Catholic Archeparchy of Philadelphia and the Byzantine Archeparchy of Pittsburgh — also acknowledged they are under investigation.

While the subpoenas hint as possible charges of sexual exploitation of minors and fraud, legal experts said that if federal prosecutors can show that church leaders systematically covered up for child-molesting priests in the past five years, dioceses could also be charged under the Racketeer Influenced and Corrupt Organizations Act, or RICO, the law originally passed to bring down the Mafia.

The nearly 900-page Pennsylvania grand jury report found that church leaders had engaged in a systematic cover-up by shuffling accused priests around to different parishes and in some cases working to prevent police investigations. Because of the statute of limitations, however, only two priests were charged as a result of the investigation. Many other priests are dead.

Pennsylvania Attorney General Josh Shapiro, who oversaw the state probe, declined to comment on the federal investigation.

In the wake of the report’s release, Shapiro said at least a dozen states opened investigations of their own and more than 1,300 accusers contacted his office on a victims’ hot line.

The report also led to the resignation last week of Cardinal Donald Wuerl as archbishop of Washington. He was accused of helping to protect some child-molesting priests when he was bishop of Pittsburgh from 1988 to 2006.

This week, the report triggered a showdown in the state Legislature, where Shapiro pushed to give child-abuse victims a two-year window to sue the church in cases otherwise too old to pursue. Church leaders opposed the change, warning it would cripple their ability to fund Catholic charities and enrich lawyers. Lawmakers ended the session Wednesday without taking action.

The difficulty of making charges stick against higher-ups in the church was illustrated when the Philadelphia district attorney’s office brought a landmark cover-up case in 2011 against Monsignor William Lynn, a longtime aide to two Philadelphia cardinals.

Lynn, first U.S. church official ever prosecuted for the alleged cover-up of child molestation by priests, was arrested on child-endangerment charges. At trial, he said he had merely followed orders from above. A jury convicted him in 2012. He spent three years in and out of prison as his conviction was twice overturned by the Pennsylvania Supreme Court. He is awaiting a third trial.