>> reporter: and, by the way, chris told detective cedillo, carter left american eagle because she was fired. cedillo filed that away and sorted through the crime scene and talked to witnesses. and a day that began at 8:30 that morning didn't end until 1:00 am. did you get any sleep? >> no, sir, i didn't. >> reporter: the story about carter cervantez and her black infiniti was just bugging him. >> well, i'm thinkin' about the case and i'm thinking, "where do i go from here?" >> reporter: might have tossed and turned all night thinking about that. but something inside him said, "nope." >> i'm not gonna be able to get any sleep. i might as well go back out there and see what i can find. >> reporter: wouldn't be his first wild goose chase. he had carter's address. so, wee hours of saturday morning, he drove over there and what do you know? >> i saw a black infiniti backed in, right in front of their apartment. >> reporter: but he didn't knock on her door. >> i was going to go ahead and basically sit here and watch the vehicle to see if it moved.