and as for the susan berman case, attorney dick deguerin insists bob had nothing to do with her murderhas been set yet, but when deguerin does go to court he faces a tough deputy d.a. named john lewin. >> never lost a case, i think. >> you know, in texas we have a saying. "ain't been a horse can't be rode, ain't been a cowboy can't be throwed." >> reporter: but will the upcoming trials solve the mysteries of robert durst? well, maybe not. which is why we're about to return to california. and that place they call the lost coast. >>> coming up, a missing teenager. >> karen, where are you? >> investigators wonder is there a link? >> robert durst is a person of interest in this case. about th. but when i started seeing things, i didn't know what was happening... so i kept it in. he started believing things that weren't true. i knew something was wrong... but i didn't say a word. during the course of their disease around 50% of people with parkinson's may experience hallucinations or delusions. but now, doctors are prescribing nuplazid. the only fda approved medicine... proven to significan