reporter: they searched her home, and later sat her down in an interview room and hooked her up to a polygraph machine. asked her questions like this one, among others. reporter: did you go to big lakes park that day? um, no. reporter: amy also denied that she shot liz. again and again. but she failed the polygraph. still, something didn t add up. when that local detective arrived at amy s place right after the shooting, he felt the hood of her car. ice cold, hadn t been driven for a while. and the neighbor said amy was home all afternoon. so was amy so nervous she blew the polygraph? or was something else going on? detective avis went to see liz at the hospital, his recorder rolling. i feel like it s just written on the wall what it is. it s amy shot you with dave s gun, isn t it? pretty much, that s what i m thinking. dave still doesn t think so. reporter: you seemed like the friendly cop. or the dumb one, i ll be whatever she wanted, as long as she kept telling u