Before she died two years ago, true-crime author Michelle McNamara made it her mission to identify a man believed to have committed 12 slayings and at least 50 rapes across California from 1976 to 1986.
On Wednesday -- four days after the second anniversary of her death -- California authorities finally arrested a suspect, leading McNamara's fans to credit her with helping to find justice from beyond the grave.
McNamara, who published the website True Crime Diary, was long fascinated by the unsolved case, dubbed the suspect the "Golden State Killer" and investigated it on her own.
"The displeased felt that (nickname) sounded too glamorous, like he was a Hollywood star. But as my research takes me across California the more I feel the moniker, with its jarring juxtaposition, is apt," she wrote in a 2014 post.
At the time of McNamara's unexpected death in April 2016, she was working on a book about her investigation for HarperCollins. Her husband, actor Patton Oswalt, finished her project with the help of lead case researcher Paul Haynes and investigative journalist Billy Jensen.
Titled "I'll Be Gone In the Dark," after a statement the killer allegedly made to one of his victims, the book was published in February. It quickly became a bestseller.
When California authorities on Wednesday announced that Joseph James DeAngelo, 72, was in custody on two counts of murder, her fans were quick to link his arrest to the release of McNamara's book, which renewed interest in the case. The serial killer and rapist was also the subject of an HLN original series, "Unmasking a Killer," which aired from March to mid-April.
Since news of DeAngelo's arrest Oswalt has been especially active on Twitter, where he remembered the countless hours his former wife dedicated to the case.
"I hope you got him, Michelle. I hope THEY got him. #IllBeGoneInTheDark #MichelleMcNamara #stepintothelight," reads one of his many tweets.
Oswalt also pointed out the irony that the arrest happened on DNA Day -- the US holiday celebrating advancements in DNA research -- since McNamara firmly believed DNA evidence would play a key role in uncovering the killer's identity.
As it turns out, she may have been right. DeAngelo was arrested after police matched discarded DNA evidence from his Sacramento area home with genetic evidence from the crimes, Ventura County District Attorney Greg Totten said.
It wasn't immediately clear Wednesday whether DeAngelo was on McNamara's radar as a suspect or how much her research may have helped investigators.
But readers of her book praised McNamara's legacy and her role in helping victims of these decades-old crimes possibly find peace.
"#MichelleMcNamara you are a true hero. I hope you are looking down and smiling. #IllBeGoneInTheDark," wrote one reader.
Many posted screenshots of an excerpt from the book in which McNamara addresses the killer directly, assuring him that he would be found.
The excerpt ends like this:
"This is how it ends for you.
'You'll be silent forever, and I'll be gone in the dark,' you threatened a victim once.
Open the door. Show us your face.
Walk into the light."
Now McNamara's family, friends and fans are rejoicing at the thought that partly thanks to her, a killer may no longer be able to hide in the dark. Oswalt will appear on "Late Night with Seth Meyers" Wednesday night to discuss DeAngelo's arrest and his former wife's investigation.