karyn bolton: no.was "payback" for a bitter break up back in 2008. karyn bolton: hard to believe someone would do that. but she's doing it. josh mankiewicz: karyn said she once overheard raven on the phone with vanessa soon after they broke up. karyn bolton: he happened to have it on speaker phone. she was screaming at him, how dare he leave her she flat out said, "all it takes is one phone call from me. it doesn't matter what i say. people will believe me. josh mankiewicz: you heard her say that? karyn bolton: i heard her say that. josh mankiewicz: you ever threaten him like that? vanessa pond: no. he-- he threatened me. josh mankiewicz: a courtroom battle between two bitterly divided families was about to come to an end. now it was up to the jury. but just after 24-hours.... word began to spread throughout the courthouse... there was trouble in the jury room. craig melvin: coming up-- craig melvin: another stunning turn was in store for both sides. vanessa pond: heartbroken, shocked, stunned. josh ma

been to the house a dennis murphy: but karyn did have one possible lead, and it was something detectivesioned one woman, a nurse, whose name came up a few times in police interviews. another job because i really need to replace you. sandra was need to replace you. sandra was badmouthing dennis murphy: and a year earlier, dr. sievers had laid off sandra's husband, frank, who'd also worked at the practice. detectives wondered, could all this have angered her enough to hurt teresa? but when sandra spoke to a local reporter, she seemed heartbroken about what happened. i learned a lot from her. when you're with somebody for seven years, it's-- it's your second home. it wasn't a job to me. dennis murphy: detectives talked to sandra, too. by the end of speaking with her, we were able to eliminate her. and like anything, hey, were you-- were you here? were you there? and everything wrapped up itself. she wasn't a likely suspect. dennis murphy: the leads were running dry. and after days of investigating, detectives seemed no closer to knowing who killed teresa. lester holt: coming up. dennis murp