‘I’ll Be Gone in the Dark’ outlines murder investigation author took on but didn’t get to finish

On Aug. 1, 1984, a 24-year-old Oak Park woman named Kathleen Lombardo was out for a jog when she was sexually assaulted and stabbed to death. The case remains unsolved.

Michelle McNamara was 14 at the time and lived just a few blocks from the alley where Lombardo’s body was found. Two days after the murder, she visited the crime scene and noted a few small pieces of a Walkman she believed Lombardo had with her at the time of the attack.

That chilling moment ignited McNamara’s interest in true crime, which became a passion and then an obsession as she eventually moved to Los Angeles to pursue a career in writing, fell in love with and married the actor and comedian Patton Oswalt, had a daughter named Alice and devoted years of her life to unmasking arguably the most prolific and monstrous serial rapist/killer most of the world had never heard of at that point — the man she dubbed the Golden State Killer.

McNamara’s pursuit of the elusive, shadowy and horrific figure who committed more than 100 burglaries, in excess of 50 rapes and at least 13 murders in California from the mid-1970s to the mid-1980s led to a widely acclaimed article in Los Angeles magazine, the bestseller “I’ll Be Gone in the Dark” (it might be the best true crime book I’ve read since Capote’s “In Cold Blood”) — and now a chilling and involving six-part documentary series for HBO, with the first episode premiering at 9 p.m. Sunday.

Two-time Emmy winner and two-time Oscar nominee Liz Garbus (“Ghosts of Abu Ghraib,” “The Fourth Estate,” “What Happened, Miss Simone?”) adds to her world-class credentials with an expertly woven narrative chronicling two equally compelling stories: the search for the Golden State Killer, and the heartbreaking story of McNamara’s own journey, which included a lifelong struggle with depression, an increasing dependence on prescription drugs as she devoted five years of her life working on the book — and her sudden and tragic death at 46 before the manuscript was completed.

McNamara is the dominant presence in the first four episodes of the series. We see her in home videos talking about the case and sharing tender moments with her husband and daughter. We hear her voice courtesy of recordings of interviews she conducted and podcast appearances. (The actress Amy Ryan perfectly captures McNamara’s voice, literally and spiritually, in voiceover readings from her book.)

We’re even privy to text messages between Oswalt and McNamara as she discusses the toll her investigation is taking on her, floats the idea of them having a second child and apologizes for spending so much time away from Patton and Alice as she becomes consumed with the book.

With McNamara painting the narrative picture, the series weaves in interviews with survivors, former investigators and “citizen detectives” — civilians who, like McNamara, worked tirelessly online to piece together obscure clues and create a profile of the man first known as the Visalia Ransacker, then the East Area Rapist, then the Original Night Stalker and finally the Golden State Killer, as McNamara dubbed him.

We see archival footage along with the occasional tastefully rendered re-enactment depicting the predator terrorizing California neighborhoods from 1974 to 1986: casing homes in quiet, middle-class suburbia; tying up the husband and threatening to kill the wife or girlfriend as he repeatedly assaulted her; taking breaks to rifle through personal belongings and even eat a sandwich or down a beer, then disappearing into the dark.

Rich Pedroncelli / AP

In April 2016, McNamara died in her sleep. She had an undiagnosed heart condition and a fatal combination of Adderall, Fentanyl and Xanax. Determined to finish what his wife had spent a half decade of her life working on, Oswalt enlisted the help of investigative journalist Billy Jensen and researcher Paul Haynes to complete the book, which became a No. 1 New York Times bestseller.

In the final two episodes of the series, McNamara remains a constant influence and subject of discussion — it’s remarkable how so many hardened homicide detectives and forensic specialists welcomed her as one of their own.

But the focus shifts to the role of DNA in the arrest of Joseph DeAngelo, a 72-year-old former cop who eventually was charged with 13 counts of first-degree murder and 13 rape-related counts, and the survivors, including several who met each other for the first time at DeAngelo’s arraignment.

When the survivors get together for a backyard garden party to toast the arrest of DeAngelo, it’s a moment of great triumph and inspiration. They’re still standing strong, and the monster who invaded their lives all those years ago is now a pathetic old man in an orange jumpsuit, behind bars.