about something shelley told her mom -- that daniel kept trying to corner her, speak to her alone. that it bothered her. his reply -- he did approach shelly, but only out of concern for nathan. >> i was actually asking her, i was like, "is there something wrong because he's literally failing his classes." >> so you, as his big brother, mother figure, whatever it was, felt a responsibility for him? and it was because of his obsession with shelley? >> i believe so. >> did she tell you to lay off? >> no, no. she actually thanked me for bringing up the issue and then that's where i left it. >> reporter: of course, it was quite easy for us to check his claim that nathan was faying his classes. was he? no. but, listen now to daniel's central claim -- that for evidence of who killed shelley, one need look no farther than that plastic baggie stained with her blood, and found in nathan's bathroom. daniel swore he didn't put it