A teacher convicted of charges in a sexual abuse case involving two students won a ruling from a state judge that could help her obtain prosecution documents to use in the defense of a civil action.

Queens Supreme Court Justice Howard G. Lane (See Profile) concluded that e-mails between three Manhattan assistant district attorneys and one of the students, Paul DeMoya, and his mother were “material and necessary” for Lina Sinha, a former principal and teacher at the Montessori School of New York, to defend herself against a personal injury action brought by Mr. DeMoya.