SERIES FINALE: When I watched this last night on HBO, and got to the climax, I was stunned by what I saw, and especially by what I heard. Over the weekend, Robert Durst, the subject of this astounding documentary, was arrested by authorities in connection with the Los Angeles murder that also is a pivotal point of this final episode of The Jinx. Halfway through this series, Durst, accused of several murders over several decades, was caught muttering to himself after the official taping session was over, unaware that his lapel microphone was still “hot” and recording. That’s an astounding mistake to make once – but twice? What he says may not be admissible in court, but it’s unforgettable. As is this flawless, important documentary.