What you already know about California’s notorious Golden State Killer and his prolific string of rapes and murders in the 1970s and ’80s might depend entirely on how plugged in you are to the world of true crime. There is no succinct way to describe our culture’s surge in true-crime stories, not just for entertainment value, but as a sort of rock to cling to in a stormy era of fears that are often as specific as they are abstract.

Ask anyone who reads true-crime books, watches countless true-crime docuseries (cable TV can’t seem to make enough of them) or listens to the always-expanding catalogue of true-crime podcasts: How much is too much?

The answers from aficionados range from a sheepish shrug to a deeply personal inventory that can include the relief that true-crime stories may provide for those with traumatic stress and troubling worries. Or it can stem from a desire to see resolution in long-unsolved cases. It can also tie in with a need for constant vigilance of one’s own security. Gruesome stories help some of us navigate a gruesome world.

Some fans, like the late Michelle McNamara, who is both the subject and spirit of Liz Garbus’s intricate and absorbing six-part documentary series “I’ll Be Gone in the Dark,” which premiered last Sunday on HBO, take their true-crime fixations online and with a higher purpose. As bloggers and ad hoc investigators, they are particularly drawn to cold cases, where deep internet dives and DNA records can run circles around the dusty-shelved efforts of initial, and futile, detective work.

Some of the biggest crimesolving news of the past decade comes courtesy of these citizen investigators, who, working alone or in online groups, discover new leads in old evidence and sometimes even match a killer by tracking down his relatives in DNA databases.

“I’ll Be Gone in the Dark,” which was also the title of McNamara’s posthumous bestseller in 2018, is a complex and thoughtful attempt to comprehend mutual fixations – not only as it pertains to the psychopathy of a serial rapist and killer, but also the allure that such a string of crimes can have on the professional detectives and determined amateurs trying to identify him.

Here, “identify” takes on multiple meanings. To identify the suspect, to process the deepest darkness, one must try to identify with the suspect. McNamara compared it to the old lagoon creature of horror-film lore, footage from which becomes a haunting motif in Garbus’s series. It’s a monster that reaches up to pull you down.

Today’s TV viewer has doubtless been pulled into similar, multi-chapter, true-crime docuseries, some good and some just hideously trite, all of which tend to take advantage of recently discovered reserves in the modern attention span – starting with the 2014 release of the hit podcast “Serial” and continuing with such projects as HBO’s own “The Jinx” and Netflix’s “Making a Murderer.”

Running counter to the idea that less is more, such series and podcasts indulge a meandering narrative style, particularly when recounting unsolved (or unjustly sentenced) crimes. They take you along for the entire hunt, whether there’s an ending or not. They thrive (and fill time) with lingering interviews, false leads and, at times, a ghoulish flair for melodrama. When done right, such works can be an enthralling experience of discovery and context; when overplayed, they can be frustrating, especially when 90 minutes’ worth of concrete material is stretched into six, eight, even 10 episodes of theorizing and supposing, padded out with endless aerial drone footage of the local water towers, rivers and school football stadiums. (What really happened? We’ll never know, but let’s go over everything five more times.)

In that regard, Garbus, a filmmaker whose unerring instinct for handling complicated and emotionally difficult material has put her at the top of her field, doesn’t waste a single minute of “I’ll Be Gone in the Dark’s” six hours. In fact, the series works as a near-perfect example of how to manage several concurrent themes, tangents and narratives at the same time, while never once failing to captivate the viewer.

Garbus and her team of producers and directors know that, despite every other subject the series will touch on, the main attraction here is the still-startling story of the Golden State Killer himself, who was given many names by local police tasked with finding him.

In his earliest break-ins, circa 1974, he was called the Visalia Ransacker. When his breaking and entering evolved into rape attacks, leading to more than 50 sexual assaults in the Sacramento area between 1976 and 1979, they called him the East Area Rapist. His re-emergence, this time as the Original Night Stalker, came a few hundred miles south near Ventura and included several murders between 1979 and 1986.

The story of how he committed his crimes and how police used DNA to finally arrest a suspect in 2018 – a former police officer named Joseph James DeAngelo, who is now 74 and pleaded guilty Monday to 13 murders and kidnappings – would stand on its own as sufficiently chilling material.

To reveal any of these facts is hardly a spoiler, given the media attention on DeAngelo’s arrest (and McNamara’s book). Yet everything that leads to it in the docuseries becomes, quite skillfully, the heart-pounding stuff of great crime stories. The arrest, when it at last comes, reveals new responses. One of the survivors in the film, Fiona Williams, marvels at DeAngelo’s frail appearance, as well as his three-car garage. “When they showed his house,” she says, “I thought, you’re kidding me. … He’s living the comfy suburban life that he wrecked for so many other people?”

“I’ll Be Gone in the Dark” is as much about McNamara, who, as a true-crime blogger and general lookie-loo, came late to the story and joined long-running online conversations with others who were fascinated by the East Area Rapist/Original Night Stalker case (EAR/ONS, for short).

McNamara, a new mom who was married to comedian and actor Patton Oswalt, took that fascination several steps further – befriending retired detectives, getting to know women who had survived the attacks, and redubbing the elusive assailant the Golden State Killer.

Drawing on McNamara’s observations, “I’ll Be Gone in the Dark” contextualizes a certain aspect of California in the ’70s, rife as it was with serial criminals (stalkers, stranglers, ransackers) who were always in the shadows, vaguely sketched on wanted posters, pursued by police departments that didn’t have comprehensive computer databases and, more importantly, lacked sensitivity and understanding for rape victims.

Eventually, McNamara produced a long, meaty Los Angeles magazine article about all of this, renewing interest in the cold cases and becoming something of a celebrity in the true-crime world. She signed a big book contract and continued her relentless search for new evidence, gaining the trust of state and local investigators – one of whom gave her access to a roomful of boxed evidence.

This is where “I’ll Be Gone in the Dark” necessarily turns its attention to how the case consumed McNamara, who struggled with stress and insomnia and showed signs of depression. Like so many people in this docuseries, she carried old hurts from the past, including the experience of being sexually harassed. She self-medicated with painkillers, sleep aids, anti-anxiety drugs and amphetamines.

An autopsy attributed her death, at age 46 in 2016, to an accidental overdose. Anyone who has ever watched a Garbus documentary knows that we are not coming away from this with anything other than the full story, from Oswalt as well as McNamara’s friends and older siblings, no matter how painful it is.

It is up to those who loved her and knew her best to finish her manuscript, which ended on her hope that DNA might provide the real break in the case and that the Golden State Killer would eventually hear a fateful knock on his door and have to answer for his crimes.

McNamara never got to see it. But it is in that tragic conclusion that Garbus and company deliver “I’ll Be Gone in the Dark’s” most striking and thoughtful aspect, as a community of survivors and true-crime fans seem to unite in their desire to speak out, reveal secrets and shine their light on the darkness.

As some of the citizen investigators, survivors and others affiliated with McNamara’s work gather to promote her book, “I’ll Be Gone in the Dark” travels to the annual CrimeCon gathering, where a camera pans across a huge audience and, perhaps unwittingly, reveals a demographic similarity in gender, age and race – it’s an auditorium full of Michelle McNamaras. I’ve yet to see any project in the true-crime genre that also takes time to so eloquently and empathetically relate to why so many people (so many women) find their place here. Fear might have drawn them to true crime, but the real payoff is a sense of courage and strength.

New episodes of “I’ll Be Gone In the Dark” (one hour) air Sunday at 10 p.m. on HBO.

Comments are not available on this story.