Dateline: Secrets Uncovered (2017)

S10E45 Facing the Music

At just twenty-five, Christy Mirack was on the verge of fulfilling her dream of becoming a teacher when tragedy struck and she was murdered. For a quarter of a century, the police worked tirelessly to uncover her killer's identity. In a surprising twist, they discovered that he had been living in the community all along, hidden in plain sight.