Exclusive: Kelli Stapleton: A Mother's Worst Nightmare

Dr. Phil continues to search for answers in a cold-case murder, interviewing Rachel, who accuses Walt of murdering her 14-year-old sister in 1985, despite his vehement denial. Walt says he passed a polygraph in 1985 and was cleared by DNA evidence — and he wants to end Rachel’s suspicion of him once and for all. Walt also claims Rachel might have been involved in her sister’s death — an accusation she strongly denies. Both agree to take a polygraph test — what will the results reveal? This program contains sexual content. Viewer discretion advised.