Tracy Smith reports on a case that sounds like an episode of a scripted crime series: A married college swimming coach named Kristen Cunnane, becoming increasingly tormented by flashbacks of sexual abuse she suffered at the hands of her female gym teacher in high school more than a decade earlier, decides to confront the memory – and her abuser. She goes to the police, carries a tape recorder to the “reunion” – and the rest of the story, which becomes increasingly and disturbingly complicated, is the one Smith tells in tonight’s edition, Kristen’s Secret.