last spotted going for a run july 18th. according to investigators, rivera followed her and abducted her about ten miles from where she was living in brooklyn. >> and then she took off running. he chased her down. >> reporter: this video capturing her smiling just days before her disappearance. her emotional family pleading for her return. >> hang in there. and we miss you, pie. come home. >> reporter: it was video captured by a neighbor's camera that helped them track the suspect down. >> the video was critical, i'll put it that way. >> alex, the suspect led police to the body, but no word on a motive? >> reporter: that's right. authorities say the suspect led them to her remains. when i asked the lead investigator about a possible motive, he said they can't