Michelle McNamara was well known among true-crime aficionados as the writer of the True Crime Diary blog and as an amateur investigator into the unsolved case of the Golden State Killer, who committed 50 rapes and at least 13 murders in California in the 1970s and ’80s. She was working on a book about his crimes when she suddenly died in 2016 at the age of 46; it was eventually published under the title I’ll Be Gone in the Dark, two years later. Now it’s the basis for an uneven, six-part HBO documentary series of the same name, whose first installment airs on June 28. Like the book, it has its strengths, but also considerable weaknesses.

It’s hard to critique an unfinished, posthumously published work; by definition, I’ll Be Gone in the Dark is not what McNamara intended, and some of the book’s passages would certainly have been improved by another pass or two. In the documentary, interviewees effusively praise the author’s writing talent, but some of her prose, as quoted in the documentary, is astoundingly clunky: “The victims slept untroubled until the flashlight’s blaze forced open their eyes”; “Until we put a face on a killer who remains a question mark, he will continue to hold sway over us.” The book ends with a bizarre, extended piece of writing addressed to the killer himself: “Fantasy adrenalized you. Your imagination compensated for your failed reality. Your inadequacies reeked.” The book’s editors did their best to assemble finished pages, scattered notes, and interview transcriptions into something coherent, but the final product still feels choppy and jumbled, at best.

Why, then, did the book go forward? Posthumous publication of this sort is usually reserved for literary greats, such as Ralph Ellison or Kurt Vonnegut. More importantly, why was her book the basis for a prestige-TV miniseries? It’s hard to discount the fact that McNamara was also the spouse of actor, comedian, and author Patton Oswalt, which makes her, at the very least, famous-by-proxy; he contributes a heartfelt afterword to the book, and he appears often in the documentary, which even includes clips of his stand-up routines.

Indeed, the miniseries, which premieres on June 28, is as much about McNamara as it is about the Golden State Killer and his victims. “She wasn’t a big me-me-me person,” her editor, Jennifer Barth at HarperCollins, notes in the documentary. “She was much more interested in other people than in talking about herself.” Even so, McNamara discusses her own life at length in the book—her obsessive streak, her fraught relationship with her mother—and Oscar-nominated filmmaker Liz Garbus (What Happened, Miss Simone?) lavishes attention on her life, as well, without making a very strong case for why audiences should be so interested in it. The documentary only superficially explores McNamara’s Adderall and Xanax use, which contributed to her early death. Garbus does interview several of the Golden State Killer’s surviving victims at length, and these sections are more affecting than anything in McNamara’s book. But a clip from the 1954 movie Creature from the Black Lagoon—a favorite film of McNamara’s (and Oswalt’s), used as a strained killer-as-monster metaphor here—undercuts a few otherwise gripping moments.

Just two months after I’ll Be Gone in the Dark was published, police arrested Californian Joseph James DeAngelo on the strength of DNA evidence that he was the Golden State Killer. The documentary struggles mightily, and unconvincingly, to give credit to McNamara for this, despite the fact that she didn’t, in fact, uncover anything that led to it. For example, McNamara is quoting as saying that she believed that advances in DNA-tracking technology would eventually catch the killer—an opinion that any viewer of CSI might share. Indeed, the latest edition of the book includes a Sacramento Bee article with the following passage:

“Did Michelle McNamara ultimately help nab the Golden State Killer?

“‘That’s a question we’ve gotten from all over the world … and the answer is no,’ Sacramento County Sheriff Scott Jones told reporters after DeAngelo’s arrest.

“Her work kept the story in the public eye, Jones said, but that’s it.

“‘There was no information extracted from that book that directly led to the apprehension,’ he said.”

It’s true that McNamara did an impressive amount of research, and she did give the murderer a “catchy name,” as she once called it in a 2013 Los Angeles magazine article, which may have helped to keep him in public’s consciousness. But does that warrant a full-dress HBO documentary? That remains a question mark.

David Rapp is the senior Indie editor.