Correspondent Tracy Smith and Producer Gayane Keshishyan Mendez discuss the case of Susann Sills, a mother of twins who was found dead at the bottom of a staircase in the home she shared with her husband, a renowned fertility doctor. The team discusses the 911 call made by Dr. Sills, the police interview with a woman investigators believed he was courting, and the defense’s unusual theory that the family dogs were involved in Susann's death.