Who could have anticipated that the most compelling figure on HBO’s Sunday-night lineup would be a 71-year-old man who might have been exonerated of a murder but freely admitted that he dismembered a corpse? Then again, Robert Durst is a real-life figure steeped in fictional overtones, capturing the seemingly unquenchable appetite for salacious crime. And the makers of “The Jinx: The Life and Deaths of Robert Durst” delivered what felt like a thriller in serialized form, culminating – in almost too-good-to-be-true fashion for the network’s purposes – with Durst’s arrest on long-simmering murder charges right before Sunday’s finale to the six-episode run.

It’s hard to comprehend the mix of hubris and sense of invulnerability and entitlement that inspired Durst to contact filmmaker Andrew Jarecki, the maker of the movie inspired by Durst, “All Good Things,” and agree to an interview. Nor could one script the final moments of the finishing installment (and SPOILER ALERT if you haven’t watched), during which Durst – speaking into an open microphone while in the bathroom – appears to confess while talking to himself, after having been confronted with damaging evidence.

“There it is. You’re caught,” he muttered, adding a few moments later, “What a disaster.”

There are, admittedly, several aspects of “The Jinx” that can be second-guessed strictly in terms of creative choices and presentation, from the use of dramatic reenactments to the decision to make the filmmakers such prominent characters in the last couple of chapters. Indeed, the padded build-up to the second interview focused almost entirely on Jarecki and his mental state in preparing for the encounter (“I’m very nervous about it,” he concedes), while Durst’s presence was limited to a series of phone calls and messages. The interview, after all that, occupied a mere five minutes of screen time.

In hindsight, some of those concerns would have likely been addressed by placing the series under the stewardship of HBO’s documentary arm, but what’s done is done. Then again, one could argue that the license afforded Jarecki within this format – operating less as a journalist than in a hybrid form of reality TV – facilitated the breakthrough that the series appeared to conjure and that renewed the interest of authorities. (Legal experts will also no doubt have thoughts about the admissibility of some of this material, some of which seems problematic even from a layman’s perspective.)

Moreover, the giant revelation dropped during the penultimate episode – the newly unearthed letter from Durst, which appeared to mirror the writing on a note that had been sent anonymously to the police – rendered much of the possible criticism largely irrelevant. To all appearances, Jarecki and collaborator Marc Smerling had accomplished what years worth of investigations could not, at least in regard to one of the three deaths that have made Durst such an object of media fascination.

Coming on the heels of “Serial,” the podcast that became an obsession for many listeners, there were legitimate questions going in as to whether “The Jinx” could rival that experience. It also felt like something of a lark for HBO.

Yet thanks to the filmmakers, with an assist from the Los Angeles District Attorney’s office and Durst himself, that has been asked and answered. And if Durst walks away scot-free this time, HBO should consider casting him in a future season of “Game of Thrones.”

Because for a public that has always harbored an interest in serial killers that goes well beyond reality, Jarecki sat down with a guy who, as one of the detectives noted early on, hardly looks like a danger to society – even the way he closed phone calls by saying “Bye-bye” had a grandfatherly ring to it – and before it was over somehow, chillingly, came away with his very own version of Hannibal Lecter.