several of whom were women. reporter: women jurors, who he believes won t like the idea of david dating mary so soon after shelley s death. but that s not the defense team s only worry. prosecutors show the jury shelley s damaged diving gear, tell them how david stopped giving her c.p.r., and present their theory that david held her down and turned her air off. they had to come up with some kind of scary story that would make the jurors who are not divers all say, oh, that s what happened. reporter: david s only chance: take the stand to defend himself. his defense attorney questions him first. reporter: then the prosecutor tries to rattle david. reporter: david begins to lose his patience when prosecutor williams pushes him about those letters he wrote to mary basler, calling her his soulmate and inviting her to spend the weekend. reporter: you came off as arrogant, a little hostile, smug. what were you thinking when you were up there? i mean, this is a moment