PHILADELPHIA — Two years ago, a federal prosecutor in Pittsburgh considered filing a racketeering lawsuit against a Roman Catholic diocese over its handling of child sex-abuse complaints, but left office before he could make the bold move.

However, a colleague in Philadelphia is now taking aim at the Church this month, sending grand jury subpoenas to dioceses throughout Pennsylvania as he tries to build a federal criminal case centered on child exploitation.

U.S. Attorney William McSwain of Philadelphia has a head start on the work, given the sweeping state grand jury report released this summer, which found that 301 priests molested more than 1,000 children over seven decades. McSwain, a Harvard Law School graduate and former Marine sniper platoon commander, was appointed by President Trump and took office just four months ago.

“It’s a courageous move, whenever prosecutors take on something that there’s no precedent for, that is uncertain. You’re investing resources with potentially no return. But it needs to be done,” said David Hickton, the former U.S. attorney in Pittsburgh who looked at the Altoona-Johnstown Diocese in 2016.

All but one of the state’s eight dioceses confirmed Thursday that they have received the federal subpoenas sent last week, and largely sounded willing to comply.

McSwain, among other things, wants to know if any priests took children across state lines for sex; viewed child pornography; reassigned predators; or used church funds or assets to cover up sexual misconduct. He has demanded the Church turn over files from any “Secret Archives,” along with financial, personnel and treatment records. And he expects to take testimony from church leaders.

“This is the first time I have ever heard of a federal investigation into child sexual abuse in a Catholic diocese or church. This is a monumental moment for clergy sexual victims everywhere,” said Mitchell Garabedian, the Boston-based plaintiffs’ lawyer who played a major role in uncovering the scandal in the Boston Archdiocese in 2002.

There’s no sign so far that the Justice Department plans a national investigation aimed at the Church.

Still, the federal government’s intervention opens a new front of legal peril for the Catholic Church, given that investigations into sexual abuse by clergy members have historically been handled exclusively by state and local authorities.

Church officials across the state — in Philadelphia, Pittsburgh, Scranton, Erie, Greensburg, Allentown and Harrisburg — said on Thursday 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.”

It could be months before the grand jury hears testimony because of the time it takes to review the cache of requested documents. He wants to know if any priests, bishops, seminarians or others committed any federal crimes.

McSwain also demanded that bishops turn over any evidence that anyone in their ranks instructed anyone not to contact police. The subpoenas seek documents related to the dioceses’ organizational charts, finances, insurance and clergy assignments.

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

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

“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.

While the subpoenas hint at 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. Most of the complaints were decades old, and because of the statute of limitations, 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 lawmakers facing opposition from the Church declined to give child-abuse victims a two-year window to sue in cases too old to otherwise file.

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.

Tucker reported from Washington. Associated Press writers Claudia Lauer in Philadelphia and Marc Levy in Harrisburg also contributed to this report