ALTOONA, Pa. — Two Catholic bishops who led a small Pennsylvania diocese helped cover up the sexual abuse of hundreds of children by more than 50 priests and other religious leaders over a 40-year period, according to a grand jury report that portrays the church as holding such sway over law enforcement that it helped select a police chief.

The 147-page report issued Tuesday on sexual abuse in the Altoona-Johnstown Diocese, home to nearly 100,000 Roman Catholics, was based partly on evidence from a secret diocesan archive opened through a search warrant over the summer.

In announcing the findings, Pennsylvania Attorney General Kathleen Kane said the diocese’s two previous bishops “placed their desire to avoid public scandal over the well-being of children.”

No criminal charges are being filed in the case because some abusers have died, the statute of limitations has expired, or victims are too traumatized to testify, she said.

Of the victims, Kane said: “Their souls were killed as children. They weren’t out playing baseball; they were trying to avoid priests.”

The report was especially critical of Bishops James Hogan and Joseph Adamec. Hogan, who headed the diocese from 1966 to 1986, died in 2005. Adamec, who succeeded him, retired in 2011.

Adamec cited possible self-incrimination in refusing to testify before the grand jury. But in a court filing, his attorney said the accusations against the 80-year-old Adamec are unfounded. He required 14 priests accused under his watch to undergo psychiatric evaluation, the filing said. Nine of them were suspended or removed from ministry, and the five who were reinstated never re-offended, his attorney wrote.

The current bishop, Mark Bartchak, is not accused of any wrongdoing. He recently suspended a few priests named as alleged abusers in the report, though the grand jury said it remains “concerned the purge of predators is taking too long.”

In a statement, Bartchak said: “I deeply regret any harm that has come to children.”

The clergy sex abuse crisis erupted in 2002, when The Boston Globe reported that the Boston Archdiocese had transferred child-molesting priests from parish to parish to protect them. Similar scandals involving hundreds of offenders and victims have since erupted across the U.S. and beyond.