PLUM, Pa. – A local teachers union official in the Plum school district faces criminal sex charges for an involvement with a minor, and his union could be running interference with investigators.

Authorities recently charged high school teachers Jason Cooper and Joseph Ruggieri with institutional sexual assault and corruption of minors, and later added charges of witness intimidation after the duo allegedly contacted their victims, The Pittsburgh Tribune-Review reports.

Ruggieri served as vice president of the Plum Borough Education Association until David Gray took over his post. Teachers told the news site Gray sent an email to PBEA members April 9 explaining that police were “visiting the homes of our members,” and asking them to report any visits for “(Pennsylvania State Education Association)/insurance purposes,” according to the news site.

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The email also advised teachers they could reschedule their police interviews if they didn’t want to answer questions, and the union would recommend an attorney for consultation.

The PSEA also sent teachers an email, advising them that they should discontinue any police interview if they feel they are the subject of a criminal investigation, and they should not “share any information about the interviews with anyone other than an attorney.”

PSEA spokesman Wythe Keever told the Tribune-Review Gray’s email “may not accurately reflect our association’s legal advice.”

“I don’t know Mr. Gray’s motives, but the PSEA’s legal staff is responsible for providing legal advice,” Keever said. He did not know whom the PSEA recommends to members for criminal defense and said the union doesn’t provide insurance to cover the cost of an attorney.

“Members who are targeted in a law enforcement investigation and are later exonerated can file claims for attorneys’ fees through the National Education Association’s liability insurance policy,” he added.

Meanwhile, the Pennsylvania Department of Education is conducting its own investigation into the teachers who allegedly sexually abused students, and may revoke their teaching licenses, spokeswoman Nicole Reigelman told the news site.

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“The bottom line is that PDE’s goal is ensure that our students have a safe and healthy environment where they can focus on learning,” she said.

Pittsburgh’s Action News 4 reports district officials were tipped off to inappropriate relationships between and students at Plum High School about two years ago, when a parent who worked at the school told administrators her concerns about Ruggieri and other Plum employees.

“This is not a matter of one bad apple. This runs much deeper,” the teacher emailed to district officials after Ruggieri’s arrest, according to the Tribune-Review. “There’s a problem and it needs to be fixed.”

Ruggieri, 40, was arrested in February on allegations he was sexually involved with a minor student at Plum High School. Police said the inappropriate conduct occurred at his home.

“We have numerous allegations that we have to investigate that involve more than one victim,” Plum Police Chief Jeff Armstrong told Action News 4. “There are several possible victims involved here.”

Police learned of Ruggieri’s alleged misdeeds while investigating Plum teacher Jason Cooper, 38, for the alleged sexual assault of an 18-year-old student. Cooper was also arrested in February.

“One teacher is bad. When you have two teachers, parents start to get concerned. They’ve been contacting us,” Armstrong said.

Ruggieri is now on house arrest with an electronic monitoring bracelet after he allegedly attempted to intimidate his victim while released on bond.

The arrest warrant for Ruggieri’s witness intimidation charge shows he called the victim on FaceTime, questioned her about discussions with police, and told her “my livelihood will be ruined,” and “my kid’s life will be ruined,” in an attempt to sway her testimony, Action News 4 reports.

Police told the news station they believe Ruggieri was involved in “numerous relationships with multiple victims spanning several years.”

The pending charges against Cooper and Ruggieri are not related, police said.