HARRISBURG, Pennsylvania — Cardinal Donald Wuerl, the Archbishop of Washington, says he expects a grand jury report being released Tuesday on the sexual abuse of children by clergy in six Pennsylvania Roman Catholic dioceses to be critical of his actions as the former longtime bishop of Pittsburgh.

Wuerl, one of the highest-profile cardinals in the United States, wrote to priests in the Washington Archdiocese late Monday, defending himself ahead of the release of a roughly 900-page report that victim advocates call the largest and most exhaustive such review by any U.S. state.

Wuerl contended that he acted diligently to protect children after learning about incidents of abuse in Pittsburgh’s diocese when he became bishop in 1988, holding the post for 18 years through 2006.

“It moved me not simply to address these acts, but to be fully engaged, to meet with survivors and their families, and to do what I could to bring them comfort and try to begin a process for healing,” Wuerl wrote.

He said he imposed a “zero tolerance” policy for clergy who committed abuse and a process to address allegations.

Wuerl said he hopes “a just assessment of my actions, past and present, and my continuing commitment to the protection of children will dispel any notions otherwise made by this report.”

Court records in a largely secret, months-long legal fight over the report say that it identifies more than 300 “predator priests.” The grand jury concluded that a succession of Catholic bishops and other diocesan leaders tried to shield the Church from bad publicity and financial liability by covering up abuse, failing to report accused clergy to police and discouraging victims from going to law enforcement.

The Pennsylvania report echoes the findings of many earlier Church investigations around the country — and in other Pennsylvania dioceses — in its description of widespread sexual abuse by clergy and Church officials’ concealment of it.

What distinguished this probe was its extraordinary scope: The grand jury scrutinized abuse allegations in six of Pennsylvania’s eight dioceses that, collectively, minister to more than half the state’s 3.2 million Catholics.

Wuerl said he expects the grand jury’s findings from the 70 years it explored will be “profoundly disturbing.”

Yet the grand jury’s work might not result in justice for Catholics who say they were molested as children. While the nearly two-year probe has yielded charges against two clergymen — including a priest who has since pleaded guilty, and another who allegedly forced his accuser to say confession after each sex assault — the vast majority of priests already identified as perpetrators are either dead or are likely to avoid arrest because their alleged crimes are too old to prosecute under state law.

The document comes at a time of renewed scrutiny and fresh scandal at the highest levels of the U.S. Catholic Church. Pope Francis stripped 88-year-old Cardinal Theodore McCarrick of his title and ordered him to a lifetime of prayer and penance amid allegations that McCarrick had for years sexually abused boys and had sexual misconduct with adult seminarians.

Wuerl has come under harsh criticism over his response to the McCarrick scandal, with some commentators questioning his claims of surprise and ignorance over allegations that McCarrick molested and harassed young seminarians.

Wuerl replaced McCarrick as Washington’s archbishop after McCarrick retired in 2006.

The Pennsylvania grand jury, convened by the state attorney general’s office in 2016, heard from dozens of witnesses and reviewed more than a half-million pages of internal documents from the Allentown, Erie, Greensburg, Harrisburg, Pittsburgh and Scranton dioceses.

Some current and former clergy named in the report went to court to prevent its release, arguing it violated their constitutional rights to reputation and due process of law. The state Supreme Court said the public had a right to see it, but ruled the names of priests and others who objected to the findings would be blacked out pending a September hearing on their claims.

The identities of those clergy members remain under court seal.

A couple dioceses decided to strip the accused of their anonymity ahead of the report and released the names of clergy members who were accused of sexual misconduct. On Friday, the bishop of Pittsburgh’s diocese said a few priests named in the report are still in ministry because the diocese determined allegations against them were unsubstantiated.

Associated Press reporters Nicole Winfield in Vatican City and Michael Rubinkam in Pennsylvania contributed to this report.