Eight former students who attended the prestigious school during Mr. Epstein’s short tenure there said that his conduct with teenage girls had left an impression that had lingered for decades. One former student recalled him showing up at a party where students were drinking, while most remembered his persistent attention on the girls in hallways and classrooms.

“I can remember thinking at the time, ‘This is wrong,’” said Scott Spizer, who graduated from Dalton in 1976…

Mr. Spizer, the fellow student who graduated the same year, said he had a clear recollection of disliking Mr. Epstein because he was spending so much time with girls in the school.

Some other students spoke on condition of anonymity, fearing retribution from Mr. Epstein. One recalled that he had made efforts to spend time with her outside of the school, and she remembered raising concerns about Mr. Epstein’s conduct with another student to Mr. Dunnan. An attorney for Mr. Dunnan said the former headmaster was not aware of any concerns about Mr. Epstein’s conduct at the school.