The Washington County Sheriff’s Office said Thursday that it had served a search warrant on Catlin Gabel School as part of its criminal investigation into allegations of sexual and physical abuse by staff members over the past three decades.

The agency served the warrant on the private school on Monday. The document was sealed at the request of investigators.

The Southwest Portland school released an explosive internal investigation last month that described repeated instances of sexual abuse by former faculty members.

The report named six former faculty members, accusing them of groping, fondling and having sexual intercourse with students. It also detailed three other cases of sexual abuse, though the perpetrators weren’t named.

Catlin officials said they provided their report to the Sheriff’s Office in November.

Ken DuBois, a spokesman for Catlin, said the school is “fully cooperating” with Washington County authorities. “We were served with a search warrant on Monday seeking documents related to the investigation,” DuBois wrote in an email to The Oregonian/OregonLive.

DuBois wrote that school trustees “reported the former educators who were found to have engaged in misconduct” to state child welfare officials and police. “Some of these educators had already been reported in the past,” he wrote.

“We continue to cooperate fully with the Washington County Sheriff’s Office, and we are updating law enforcement when we have additional relevant information about educator misconduct,” he wrote.

Prosecutors have only so long to file charges. It’s likely too late to file criminal charges in many of the Catlin cases, which date back to the 1970s and ‘80s, legal experts say.

Oregonian staff writer Jeff Manning contributed to this report.

-- Noelle Crombie; ncrombie@oregonian.com; 503-276-7184; @noellecrombie

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