A Massachusetts investigation found evidence that more than 270 Catholic priests abused nearly 1,000 children in three dioceses over the course of a century, the state’s attorney general said on Wednesday.

The report, released by Attorney General Andrea Campbell, covers the Fall River, Springfield and Worcester dioceses. It identifies only a fraction of the priests investigators linked to the abuse, but the named cases show how church authorities prized priests who related well to youth, and how they avoided accountability while children were exposed to further danger, according to The Boston Globe, which reviewed the findings.

Many of the failings repeat what the Globe’s Spotlight team uncovered two decades ago in the Archdiocese of Boston, an exposé that set off a global wave of investigations. The new report describes problems from top to bottom of the hierarchy.

One of the priests was the notorious James Porter, ordained in Fall River in 1960, who served in North Attleborough and New Bedford. He was ultimately accused of molesting more than 100 children over 14 years as a priest. In 1992 the church settled with 68 of his alleged victims for at least $5 million, and the next year Mr. Porter pleaded guilty to sexually assaulting 28 children in his parishes; he was sentenced to 18 to 20 years in a maximum-security prison.

The scandal pushed the Fall River Diocese, then led by Bishop Sean O’Malley, to create its first review board and adopt policies for reporting abuse allegations to civil authorities and “barring diagnosed pedophiles from ministering within the diocese,” according to the report.

The report found the problem extended to seminaries. Diocesan officials were in some cases “fully aware” that seminarians had faced previous allegations of abusing children, investigators said. The Rev. Thomas Teczar was ordained in the Diocese of Worcester in 1967 despite having been fired from a summer job at the Nazareth Home for Boys in Leicester over allegedly inappropriate conduct with boys. Worcester Bishop Bernard Flanagan decided Mr. Teczar had “worked out his problem.” He became “one of the most prolific abusers” in the Worcester Diocese and later in Texas, where he was convicted of aggravated sexual assault and indecency with a child, the report said.

The Rev. Robert Kelley had a reputation for inappropriate behavior before his ordination in 1968 and was known for his “easy approach with children,” investigators said. Within a year he began abusing his first victim, an 8-year-old girl, at Notre Dame parish in Southbridge. The girl reported the abuse to his superior and was told “she was exaggerating and misinterpreting Kelley’s acts of rape and sexual assault,” the report said.

Mr. Kelley said in a deposition that shortly after his ordination he told Boston Cardinal Humberto Medeiros of his “affinity for young girls.” No restrictions followed. Another victim recalled that in the early 1970s the choir director at Notre Dame would leave the girls with Mr. Kelley before rehearsals, where he would “give them lollipops, pull them onto his lap one by one, and fondle their genitals,” the report said. He was convicted in Massachusetts in 1990, after pleading guilty to child rape and indecent assault and battery on a child, and convicted again in 2003.

Investigators found evidence that concealment reached the top of diocesan authority. Two former Springfield bishops, Thomas L. Dupre and Christopher J. Weldon, appear on that diocese’s list of credibly accused clergy; they led its churches for a combined 36 years. A Hampden County grand jury indicted Mr. Dupre in 2004 on two counts of child rape from his years as a parish priest in the 1970s, making him the first Roman Catholic bishop in the country indicted on child sex-abuse charges. The case was never prosecuted because the statute of limitations had expired, and the Vatican never punished him beyond accepting his 2004 resignation, which the diocese attributed to health reasons.

The Rev. Ronald Provost, a popular Worcester priest who used federal grant money to run a street hockey league for children, was convicted in 1993 of posing a child nude in a pool locker room. The diocese put him on “sick leave” and sent him to a Maryland treatment center. More than a decade earlier, Mr. Provost said, he had told then-Auxiliary Bishop Timothy Harrington that he had taken nude photographs of boys; Mr. Harrington denied knowing about any “problem” and testified in 1996 that he had sent Mr. Provost for “career counseling.” Mr. Provost was removed from the ministry in 1992. In 2021, Pope Francis dismissed him from the clerical state.