must have been chanin as she was being attacked. 9:17 a.m. >> 911, what are you reporting? hello? >> what it sounded like was if somebody was struggling over the phone. you could definitely hear a female's voice kind of urgh. but that's all it amounted to. >> reporter: but who was the attacker, the car salesman, the teacher, or somebody else? now the investigators had to go back over those alibis and compare them to the time of the 911 call. they started with the salesman, tom walker. were you at work all day thursday? >> except for the funeral. >> reporter: his phone never pings off any of the towers in the deer park region. he's at work on december 1st. he attends a funeral. we confirmed that. >> reporter: the salesman, the guy who sent that racy request for a photo, was in the clear.