Bruce L. Castor Jr., the former Montgomery County prosecutor now serving as the highest-ranking lawyer in the state Attorney General's Office, plans to testify next week during a key Senate hearing on a bill that has pitted child sexual-abuse victims against the Catholic Church.

In an interview Thursday, Castor confirmed his appearance Monday before the Judiciary Committee to discuss the constitutionality of a measure to let victims sue attackers and the institutions that employed them decades after the abuse occurred.

Castor wouldn't say if he would argue for or against the bill. "I'd just as soon people find out my opinion when I testify," he said.

He said, however, that it seemed less clear-cut that such a law would be allowed by the Pennsylvania Constitution than by the U.S. Constitution.

"All of us who are in law enforcement want there to be opportunities to catch criminals, whether civil or criminal," Castor said. "But there are constraints that the Constitution imposes upon executive officers in carrying out those duties."

The bill passed overwhelmingly in the House in April amid disclosures of clergy abuse and alleged cover-ups in the Altoona-Johnstown Diocese. But it has become the subject of a fierce lobbying fight in the Senate. Monday's hearing marks its first public airing in that chamber.

The Judiciary Committee is led by Sen. Stewart Greenleaf, Castor's onetime law partner and a fellow Montgomery County Republican. Greenleaf has declined to publicly support or oppose the bill, saying only that he wants to fully examine constitutionality concerns. He also has not said who else will be called to testify on the issue.

The proposal would extend from age 30 to 50 the deadline for victims to sue abusers or the institutions that employed or supervised them. It would apply retroactively, for the first time enabling some Pennsylvanians sexually assaulted as children in the 1970s, '80s or '90s to seek damages.

Echoing arguments made in other states, critics of the measure have made constitutionality a pillar of their battle, contending it would be illegal to suddenly make people and organizations liable for offenses that previously had been deemed too old to be covered under the law.

Church officials warn that such initiatives have led dioceses in other states into bankruptcy, and could financially devastate Pennsylvania parishes and schools.

In announcing the Altoona-Johnstown findings of an investigative grand jury in March, Attorney General Kathleen G. Kane called for abolishing the civil statute of limitations entirely as a way of delivering justice to victims.

Castor said he broached with Kane the idea of examining the constitutional implications last month. The pair met with Greenleaf a few weeks ago, he said, to discuss Castor's testifying.

"It was consensus among the three of us that I would research the particular issue that Sen. Greenleaf was interested in, and I would render an opinion on behalf of the Office of Attorney General," said Castor, whom Kane hired as solicitor general to act on her behalf after she lost her law license.

Castor joined the office days after its prosecutors released the Altoona grand jury revelations and filed charges against three leaders of an Altoona-area Franciscan order. The priests are accused of allegedly helping conceal a predatory friar who abused more than 100 children at a Johnstown high school, and abused many others beyond Pennsylvania, too.

Kane awaits trial on charges that she illegally leaked, in an unrelated matter, confidential grand jury material.

Just days after Castor's appointment, the state House reversed a decade of opposition and approved, by a 180-15 vote, the bill to retroactively extend the civil statute of limitations.

Since then, opponents, led by the Insurance Federation of Pennsylvania and the Pennsylvania Catholic Conference, which represents 10 dioceses across the state, have campaigned to stop the bill from becoming law.

To produce his analysis on constitutionality of the civil sex-abuse law, Castor said he would use documents on file with the Attorney General's Office and a batch of written analyses Greenleaf had collected.

Castor noted that he and Greenleaf have a long history, both serving as law partners at the firm Elliott Greenleaf from 2008 to 2013. But he said that would play no role in his testimony.

"In this instance, I'm being called upon as the attorney for the commonwealth to render an opinion to the General Assembly, and that's what I'm going to give them," Castor said. "I have no personal desire that it come out one way or another."