A True-Crime Vanguard Releases Its Final Installment

Some Netflix subscribers who stumble across “The Staircase” might wonder if it was influenced by “Making a Murderer,” “The Jinx” or “The Keepers,” which are just a few of the multipart crime documentaries that have captured the public’s attention in recent years.

Actually, it’s the other way around. “The Staircase,” which debuted in America in 2005 and gets an update Friday on Netflix, helped create the modern template for true-crime TV, a booming subgenre that shows no signs of slowing down (and even generated its own pitch-perfect parody, Netflix’s “American Vandal”).

Some of the influence is aesthetic. As is the case with “The Keepers” or “OJ: Made in America,” “The Staircase” is deliberate and quietly observational; it never relies on an exploitative tone or a prurient approach to achieve its goals. In at least one case, the influence goes even deeper. According to press notes for “The Staircase,” a few years ago, its director, Jean-Xavier de Lestrade, consulted with one of the creators of “Making a Murderer,” which has a number of tonal, structural and thematic elements in common with the earlier documentary.

Perhaps “earlier” isn’t the most accurate adjective: “The Staircase” is now both old and new. It chronicles the years of legal travails that followed the death of the telecom executive Kathleen Peterson, who met her end in late 2001 at the bottom of a set of stairs in her well-appointed home in Durham, North Carolina. Her novelist husband, Michael Peterson, was charged with her murder. The compulsively binge-able 13-part Netflix series is a collection of three different stages of the tale: The original eight-part series tracking the case and trial, which aired on SundanceTV in 2005; a two-part update from 2013; and three new episodes produced for Netflix.

The final installment does indeed wrap up the legal aspects of the story. But the knotty, ambiguous elements of “The Staircase,” which clearly influenced many later crime documentaries and were even mined by a number of scripted dramas, are likely to linger in the viewer’s mind.

The question of whether Kathleen Peterson’s death was the result of a murder or a horrible accident is unlikely to ever be settled to the satisfaction of everyone connected to the case. Her sisters, a small but vocal part of the documentary, make it clear they think she was killed. Four of her family’s children stuck by Michael Peterson through many dark days, but Kathleen Peterson’s daughter from a previous marriage sat on the prosecution’s side of the courtroom.

Which faction is right? “The Staircase,” which focuses on whether Michael Peterson was treated fairly by the legal system, doesn’t answer that question. In the show’s press kit, de Lestrade says, “I’m not sure I know more about Michael Peterson than the first day I met him.” Viewers may end up feeling the same way, even as they willingly travel down the rabbit hole of the stranger-than-fiction Peterson case.

“The Staircase” stood out in 2005, that much is unambiguous. When it debuted, serious documentaries didn’t usually air on basic cable, and most had running times of around two hours. Unlike much cable-TV coverage of crime, then or now, it was deliberate and thorough. As a Frenchman, de Lestrade aimed partly to put the U.S. justice system under the microscope, as he had in his Oscar-winning 2001 documentary “Murder on a Sunday Morning,” which chronicled the case of a poor African-American teen accused of killing a tourist in Florida.

Michael Peterson had far more money and resources than that defendant, but he had also been a newspaper columnist who had needled Durham politicians and prosecutors. It also emerged that he is bisexual, a fact prosecutors relentlessly used to imply that he could not be trusted, not just as a spouse but as a human. Without going into details that would spoil key aspects of the show, other elements of the prosecution proved even more problematic. As one lawyer says late in the season, “It’s pretty devastating to see what can pass for science and justice in a courtroom.”

Despite de Lestrade’s compassionate approach, there are gruesome elements, and in lesser hands, “The Staircase” could have been a vehicle for crude voyeurism. Instead, the series is infused by a sense of intelligent curiosity and unforced immediacy. One expects to hear Michael Peterson’s 911 call and to see late-night conferences among fatigued lawyers, but de Lestrade also follows family members as they visit Kathleen Peterson’s grave, throw birthday parties or simply stare into space after the latest devastating setback.

There’s an element of luck at play — there’s no way de Lestrade could have seen some of the case’s most jaw-dropping twists coming — but he deftly folds even the most shocking developments into measured episodes that rarely wander or overstay their welcomes. And despite the grief at its heart, “The Staircase” never lapses into grimness or plodding pessimism. People laugh and make dark jokes, and de Lestrade allows quiet moments to breathe. His outdoor compositions are particularly evocative; a scene in which a woman detaches rose petals from a stem as she stands over a grave is both gorgeous and elegiac.

Michael Peterson is generally affable and chatty, however badly things are going, and sometimes he puffs on a pipe or sips red wine as he discusses various bizarre and humbling situations. His lawyer, David Rudolf, is every bit his talkative match, combining a competitive drive with a very human sense of exhaustion and frustration as the case grinds on.

The most stealthy and welcome twist of the last third of “The Staircase” is how it turns into the story of Martha Ratliff and her sister, Margaret Blakemore (formerly Ratliff), whose entire adult lives have been shaped by this strange, overwhelming story. After their parents passed away when they were very young (and the eerie circumstances of their mother’s death figures into the narrative of “The Staircase”), the Ratliffs were adopted by Michael Peterson, and once they became part of a blended family that included his two sons and Kathleen Peterson’s daughter, Ratliff and Blakemore called them Mom and Dad.

The sisters weren’t long out of high school when the saga began; over the ensuing 17 years, they’ve spent countless hours in courtrooms, watching almost every moment of testimony and sometimes silently crying on each other’s shoulders. Whether Michael Peterson is guilty, everyone around him paid a price, and the suffering and resilience of these women, tragic upon first viewing in 2005, now comes off as inspirational without being cloying (de Lestrade doesn’t do sappy).

The sisters lost not one family, but two, and came back from an unfathomable series of tragedies to build what appear to be meaningful lives. The bleak indictment of “The Staircase” on North Carolina’s legal system is more than offset by the sisters’ unrelenting devotion to their family — and to each other.

“True crime” is all the rage, perhaps in part because the label contains a trace of wish fulfillment, a suggestion that we can finally learn the truth of a tragedy if we only delve deeply enough into its details. What really happened in this case? I have my theories, but they’re only that — imperfect conjectures. The only claim I can make with confidence is that “The Staircase,” ruminative and humane to the end, remains one of the finest examples of this genre. With the right approach, a complicated whodunit can supply truths about the best and worst of the human condition, even when the “truth” of the case is destined to remain beyond our grasp.