Police are investigating a teacher at Aberdeen High School who allegedly committed “a sex act,” a schools spokeswoman said. Harford County Schools spokeswoman Jillian Lader said the teacher is no longer employed. Lader declined to name the teacher or say if the alleged act involved a student. She said the district will cooperate with Aberdeen police and the Harford County Child Advocacy Center. “Harford County Public Schools does not tolerate inappropriate conduct by staff members,” she said in a statement. “We take all allegations against staff members seriously. Counselors will be available to students.