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. reporter: for more than four hours, he sat in his car, cold but patient. then about 8:00 a.m. saturday morning, he saw the lights of the infiniti flash as if someone was unlocking it remotely. i see the male enter the driver s seat of the vehicle. i then see a female enter the passenger side of the black infiniti. reporter: they drove off. the detective followed. and after a few minutes the infiniti pulled into, of al