>> okay. show me a picture then. >> reporter: you showed him a picture of annie. >> yep. >> brittany? do you mean brittany? >> no, it's annie. >> reporter: detectives thought daniel was lying, and they were done playing around. >> what if i told you she's dead? >> i didn't do it. what the [ bleep ]? if you guys think i did this, i do want a lawyer. >> okay. >> because there's only -- >> we're done. >> the only thing that is shaking me. >> we're done, daniel, because i think you did it. >> well, if you think i did it, then you've got the wrong guy, man. for real. >> good luck. >> find the right guy. >> reporter: derek was confident he had. they booked daniel for annie's murder. >> reporter: l.j., whoever he was, still hadn't turned up, but detective derek johnson still thought he'd wrapped up his first homicide. all he needed was the lab to confirm that the blood found in daniel's home was annie's. but then the lab called and everything unraveled. coming up --