In the early hours of March 3, 1993, someone snuck into the Maryland home of Millie Horn, where she lived with her disabled eight-year-old son, Trevor, and his nurse, Janice Saunders. After shooting both women in the head multiple times, the intruder smothered Trevor Horn to death, then quietly left the house. Hours later, the bodies of all three were discovered by Millie’s sister, who stepped by to check on them.