Michelle McNamara’s hunt for the Golden State Killer may have been cut tragically short, but her story continues to live on.

EW has confirmed that HBO Documentary Films has acquired the rights to McNamara’s posthumous true-crime book I’ll Be Gone in the Dark, a powerful read that tracks McNamara’s obsessive search for an elusive serial killer and rapist. Published in February with an afterword by McNamara’s widower, Patton Oswalt, the book quickly surged to the top of the New York Times best-seller list and earned rave reviews (including here at EW). HBO is set to develop a docuseries out of it.

“HBO taking on this story will advance the passionate pursuit that Michelle shared with dozens of men and women in law enforcement — to solve the mystery of one of California’s most notorious serial killers,” Oswalt said in a statement.

Oswalt previously spoke to EW about the book and McNamara’s motivation for writing it. “[Michelle] was a very logical person with a lot of compassion,” he said. “When she saw someone act with such cruelty, the logic part of her brain would kick in and go, ‘Well, that kind of cruelty should be met with justice, and there should be someone to answer for the victims.’ To have all of those threads and have it be open and unresolved for so long really ate away at her sense of order. She took on the pain of the survivors and of [those] that lost family members because of this guy. That’s what drove her.”

McNamara had been working on I’ll Be Gone, and in turn vying to unmask the Golden State Killer, for nearly a decade before her untimely death in 2016. With the help of McNamara’s top researcher and others, Oswalt was able to compile her research and notes into a finished product, with the book’s final section outlining just how far McNamara got in cracking the case. “If Michelle had been married to somebody else, I’m not sure that they would have pressed on with the book and been able to help make it happen in the way Patton did,” Jennifer Barth, McNamara’s editor at HarperCollins, told EW. “It was a total commitment. … He’s just been a real champion.”