An investigation into allegations of sexual misconduct at a Boston seminary has been widened to cover all seminaries belonging to the archdiocese, according to Cardinal Sean P. O’Malley.

The cardinal also announced the expanded inquiry will be led by former U.S. attorney for Massachusetts Donald K. Stern, who led the federal government’s campaign against organized crime in Boston.

On Aug. 10, O’Malley announced he had instituted an investigation into St. John Seminary, the main institution for training priests in the Archdiocese of Boston.

The investigation came after Facebook posts by two former seminarians described incidents of heavy drinking and sexual impropriety being common at the school.

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On Oct. 11, the cardinal said he was expanding the review to the other two seminaries sponsored by the archdiocese: Pope St. John XXIII National Seminary in Weston and Redemptoris Mater Seminary in Chestnut Hill.

O’Malley said the expansion of the review was “to meet the generally expected levels of transparency and accountability” and added that he wanted to “reassure the seminary communities and the wider public that these are institutions committed to the highest standards of integrity, respect and safety for our seminarians, faculty and staff.”

The cardinal said Stern – who prosecuted James “Whitey” Bulger, among others – will lead the review, which will be conducted by the law firm Yurko, Salvesen and Remz.

O’Malley also said he was committed to releasing an independent report that addresses any issues arising from the review and identifying the steps necessary to fix any problems.

“I want to assure all participants of the integrity of this process and my confidence that truth and full disclosure will ultimately unify us all,” the cardinal said.

Massachusetts attorney Mitchell Garabedian, who has represented several victims of clerical sexual abuse, released a statement on Thursday saying he doubted the seminary investigation will be truly independent.

“History has taught us that the Archdiocese of Boston is incapable of having itself fairly investigated by an entity the Archdiocese of Boston has hired to conduct the investigation,” he said.

“Since the expanded investigation authorized by the Archdiocese of Boston is not truly independent, many clergy sexual abuse victims feel the investigation will be unfair and biased,” Garabedian wrote.

O’Malley heads the Vatican’s Pontifical Commission for the Protection of Minors and is considered the Church’s leading voice on safeguarding measures.

He came under scrutiny earlier this year when it was revealed his secretary didn’t give him a letter in 2015 expressing concerns about now-disgraced former Cardinal Theodore McCarrick.

A statement dated Sept. 9 and published on the archdiocesan website confirmed that, in the future, O’Malley himself will handle all correspondence either related to his work as president of the Pontifical Commission or on the subject of abuse generally.