Choate Rosemary Hall, the elite Connecticut boarding school, said on Thursday that at least 12 former teachers had sexually molested - and, in at least one case, raped - students in a pattern of abuse dating to the 1960s. A report prepared by an investigator for the board of trustees [said that] the parents of a Choate student complained to the school in the early 1980s after their daughter contracted herpes from an English teacher. And in another case, the report describes a student's rape on a school trip to Costa Rica. None of the teachers' actions were reported to the police. Choate ... is the latest in a string of prestigious private academies that have faced accusations of sexual abuse by faculty members, including St. George's School, in Rhode Island, and Horace Mann and Poly Prep in New York City. In a letter to members of the school community that accompanied the report, Michael J. Carr, the chairman of the board of trustees, and Alex D. Curtis, the headmaster, apologized and thanked the victims who came forward. The report names 12 former faculty members who it says abused students, both male and female. In some cases, faculty members had sexual relationships with students for months. For years, the school kept allegations of sexual misconduct from getting out, according to the report. "Sexual misconduct matters were handled internally and quietly," it said. "Faculty was ... was cautioned to say nothing about the situation if asked."