reporter: soon clarkstown police detectives stephen cole-hatchard and earl lorence were on the scene. they noticed that susanne looked a wreck, standing in front of the house in the snow. susanne is in the driveway, at the foot of the driveway, kind of pacing, looking rather frazzled. reporter: she told detectives what she told the 911 operators, that peggy tripped over the cat. her mother must have tumbled down the stairs and stabbed herself with the knife. reporter: while detective cole-hatchard stayed outside with susanne, detective lorence went inside the house. this is police video of the scene taken that morning. lorence knew right away, this was no accident. no way did she fall down the stairs and trip over a cat. reporter: detective lorence saw peggy had been strangled, then stabbed. and it also looked as if she d been beaten with a statue head found under her body and a gold metal ball near her hand.