Baltimore — A four-year investigation of Baltimore’s Catholic archdiocese reveals the scope of 80 years of child sex abuse and torture and how church officials often covered it up and, in some cases, paved the way for further abuse.

Among the stories: A deacon who admitted abusing more than 100 children. A priest who chained and whipped boys for his own gratification. Another priest who, after receiving psychiatric treatment, went on to abuse 20 students at a Baltimore boys’ school.

The Maryland Attorney General’s Office released Wednesday its “Report on Child Sexual Abuse in the Archdiocese of Baltimore.” Its nearly 500 pages tell how 156 clergy and other church officials tormented more than 600 children and young adults, abuse dating back to the 1940s. The Baltimore archdiocese covers Baltimore City and nine counties in Central and Western Maryland.

The report names at least 36 abusers who are not listed on the Archdiocese of Baltimore’s online list of 152 priests and brothers credibly accused of abuse. Ten more abusers’ names were redacted.

The breadth of the abuse and its depravity, the report’s authors wrote, is “astonishing.”

Victims lobbied the office to start the investigation, particularly after the Pennsylvania attorney general produced a similar report in 2018. Democrat Brian Frosh, then Maryland’s attorney general, launched the probe later that year. Since then, investigators have interviewed hundreds of survivors and pored over hundreds of thousands of internal church documents.

Their discoveries exposed the full story, for example, of Father John Joseph Mike, who served in parishes around Timonium, Baltimore, Halethorpe and Clarksville before being transferred out of state in 1988. While Mike was charged with abusing a boy in 1987 and pleaded guilty, an archdiocese official said at the time that his case “did not involve sexual contact.”

In fact, the report said, Mike sadistically abused at least seven teenage boys for his sexual gratification. In 1987 at St. Louis parish in Clarksville, one victim was made to wear a loincloth while Mike poked him with a heated pin and forced him to run laps around the parish gym as Mike lashed him with a bullwhip. Mike tied the victim up, suspending him from a basketball backboard, and whipped him 150 times, according to a diary entry from the victim.

One of the newly public names, Deacon Leo O’Hara of Baltimore, admitted to Anne Arundel County authorities in 1987 that he had molested more than 100 children since 1953. He was not charged in that case because the county state’s attorney’s office could not identify any of his victims. O’Hara died in 1994.

Beyond the individual cases, the report delved into the Catholic Church’s efforts to cover them up.

“The staggering pervasiveness of the abuse itself underscores the culpability of the Church hierarchy,” the authors wrote.

Priests who abused children were often known to the diocese, yet little was done to stop them, according to the report. For example, Father Lawrence Brett admitted in 1964 to abusing a boy in Connecticut. Church officials there sent him to treatment in New Mexico, where he continued to abuse boys, and he then was transferred to Calvert Hall College High School in Baltimore, where Brett abused at least 20 more, the report states.

According to the report, police and prosecutors treated the church with deference when they became aware of abuse, seemingly uninterested in learning what diocesan leadership knew and when. In some instances, the local press was complicit.

In one case, the report says, Archbishop Francis Keough in 1958 secretly resolved an accusation with the help of an unnamed Baltimore Circuit Court judge. Keough promised to send Father Gerald Tragesser, accused of abusing a 13-year-old girl, to treatment and banish him from Maryland. And while the victim’s mother, who Keough described as a “non-Catholic,” wanted the case publicized, Keough used the “happy influence of a highly placed newspaper man” to keep any story from being published, according to letters Keough wrote to fellow priests. The report did not identify the newspaper.

In 1987, the head of the sex crimes unit for the Baltimore state’s attorney’s office declined to prosecute Father Robert Newman, who admitted to abusing 12 boys between the ages of 9 to 15 over a 15-year period. That prosecutor, who the report doesn’t name, said she saw “the value of trying to keep a man like this in ministry,” according to the report. Newman was sent to a treatment center and then assigned to the Archdiocese of Hartford, Connecticut, where he remained a priest until his abuse was made public in 2002.

The report called for the state to amend its civil statute of limitations for child sex abuse in Maryland. Just 40 minutes after the report’s release, the Maryland Senate passed the Child Victims Act, which would remove the statute of limitations on child sexual abuse lawsuits. The legislation is headed to Democratic Gov. Wes Moore, who has said he expects to sign it into law.

The Maryland Catholic Conference, which represents all three dioceses operating in the state, opposed the bill at every turn and is expected to challenge it in court.

The Most Rev. William E. Lori, archbishop of Baltimore since 2012, said the “enormous” history of abuse represents a moment of “shock” and “horror,” for himself and Catholics everywhere.

“It is a day of deep sadness, but it is also a day for us to focus on the victim-survivors, upon those who have been harmed and who carry around in themselves the effects of sexual abuse,” Lori said in an interview with The Baltimore Sun.

Brown said the office has issued subpoenas to two other dioceses that include parts of Maryland as part of ongoing investigations into abuse in the Archdiocese of Washington, D.C., and the Diocese of Wilmington, Delaware, which covers part of the Eastern Shore.

“While our focus has been on completing the arduous, difficult task,” of the Baltimore report, Brown told reporters shortly before its release, “we did not sit idle when it came when it comes to the Archdiocese of Washington, D.C., in the Diocese of Wilmington, Delaware. So, those investigations are ongoing.”

The report says the responsibility for the cover-up lies with past archbishops of Baltimore, but its authors wanted to highlight senior members of the archdiocese staff who advised the top priest at the time. However, five of those officials’ names are among those redacted from public view.

In some cases, the church spent far more on services for abusive priests than it did for victims. In 1993, a man who came forward with allegations against Father James Dowdy, who worked in at least half a dozen parishes from the 1970 through the 1990s. The man said Dowdy kissed and inappropriately touched him for nearly a decade when he was between 16 and 24 years old. Dowdy was placed on administrative leave in 1993.

Three years later, the archdiocese agreed to pay the victim’s counseling and medication costs, in addition to paying for ongoing therapy for Dowdy. A living subsidy was paid to Dowdy through 1997, when he was formally stopped working for the church. Health coverage continued after his separation.

The archdiocese calculated it had paid $99,000 to Dowdy since 1992, exclusive of counseling and treatment, which cost another $60,000. The victim received less than $9,000.

Wednesday’s release falls both during the conclusion of Lent, the 40-day period of fasting and repentance that precedes Easter, and Holy Week, the most sacred week on the Christian liturgical calendar, a time when believers commemorate the suffering, crucifixion and resurrection of Jesus that lie at the core of their belief.

“I think Holy Week is a good time for this to be released, because it is a time when we have to come to terms with a betrayal of trust, and a time when we lay this at the feet of the crucified Jesus and beg for forgiveness,” Lori said.

Frank Szustak, a Baltimore resident whose home parish is St. Ignatius Church on North Calvert Street, called harming a child “the worst form of transgression.” He attended Mass on Wednesday at the Baltimore Basilica of the Assumption.

Of the consequences of the report for the church, he said: “It’s a purification period.”

Baltimore Sun reporters Giacomo Bologna, Hayes Gardner, Hannah Gaskill, Abigail Gruskin, Sam Janesch, Cassidy Jensen, Jean Marbella, Lorraine Mirabella, Emily Opilo, Angela Roberts, Lia Russell and Amanda Yeager contributed to this article.