A special-education teacher, Lillian Becker, heard about a job opening at the school in 1998 and went for an interview. It was her first time on the campus, where she saw a schoolhouse, trailers and a red barn arranged on a hill that sloped gently down to a pond.

“It looked wonderful,” Ms. Becker said in a recent interview. “Very professional, very clean, very neat and orderly and everybody was very friendly. They had a student give me a tour. She just seemed so happy to be there.”

Ms. Becker got the job. On her first day, she saw something strange. She was asked to monitor a timeout room for 20 minutes until a staff member arrived to take over. “A storage room, probably like 6 feet wide by 12 feet long,” she recalled. “On the floor was this student wrapped in a blanket with duct tape to hold the blanket shut. Just the head was sticking out.”

She was told the student was at risk of hurting others or himself.

She settled into her job as a de facto nurse, making outside medical and dental appointments for students and tending to their aches and pains. She saw other practices that, looking back, she wonders why she didn’t openly question.

The school was arranged in “families,” with staff members designated as “Mom” and “Dad” and their “children,” the students, eating meals together before retiring to bunk beds in trailers, separate for boys and girls. A regular occurrence during meals were “table topics,” when students would stand and accuse, or “bring up,” another classmate over some infraction, Ms. Becker and former students said.

“Susie would get up and say, ‘I want to bring up John,’” Ms. Becker said. “John had to stand up. Now it’s time to basically break this kid down. ‘I saw him flirting,’ something like that.” What regularly followed was a tirade of mocking and scolding from other students and adults, she said. “The staff would chop this kid up.”

Sanctions varied, some involving food — a diet of tuna fish on a dry English muffin was a common punishment — or menial labor, with students burying rocks in the dirt one day, only to be ordered to dig them up the next. Others were social in nature, called “blackouts.”