she looked around she noticed something. blood not just where elizabeth lay, but high up along the staircase walls, too. too much blood, she thought, for a slip and fall. >> if you fell down the stairs, why would there be blood splurted up the side of the walls?" it didn't make any sense to me. >> reporter: and she says there were household details out of order: like the table that liz set out every night with the girls' breakfast plates. it was bare. the snow boots she routinely left by the front door, still on her feet. >> liz never wore her boots in the house. she'd always took her boots off. and that was another clue to me that something was wrong. it's obvious that she was either running from someone or trying to escape. >> reporter: amybeth thought a full-fledged investigation would ensue. but, as she tells it, michael peterson spoke to the authorities that day, relating that elizabeth had a hereditary bleeding disorder. perhaps she'd had a stroke and fallen down the stairs.