This is 19-year-old Sade Robinson leaving a bar with [music] her date, unaware that these are the last hours of her life. While she's been enjoying the chance to meet someone new, her [music] date has been focused on something darker, far darker. And just minutes from now, he'll put that plan [music] into motion. What happens next will lead Milwaukee police into [music] one of the most disturbing investigations of their careers. >> It's just on the lake there. >> A body what down there? >> A leg, a leg, a human leg. >> 19-year-old Sade Robinson reportedly went on a date the previous evening and hasn't been seen since. >> Ms. Robinson, Milwaukee police, please answer the door. We're going to come in otherwise. >> I don't hear anything. >> Nobody's seen her since the date. >> [music]