I've Lost My Mother, My Stepsisters and My Father

Kathleen peterson was found dead at the bottom of a staircase. She had suffered multiple lacerations to the back of her head, like she was bludgend to death. Investigators were picking through michael peterson's past, turning the clock back some 20 years and taking a peek at his previous life away. What they would discover was beyond erie. How can michael have found two women dead at thebottom of a staircase?