Golden State Killer Case: How Michelle McNamara, Patton Oswalt’s Late Wife, Helped Catch Suspect

Michelle McNamara was three-quarters of the way through her book, “I’ll Be Gone in the Dark,” when she died in April 2016.

As investigators made an arrest in the Golden State Killer case Wednesday, those close to the woman who made it her mission to identify the suspect who cops said terrorized California for more than a decade, paid tribute to the dogged writer who was unable to see her life's work realized.

Michelle McNamara was three-quarters of the way done with her book, "I’ll Be Gone in the Dark," when she died in April 2016.

At just 46 years old, the true crime writer had an undiagnosed heart condition and had taken a mix of prescription drugs, including Adderall, the pain narcotic fentanyl and the anti-anxiety medicine Xanax. 

She died in her sleep, leaving behind her husband, comedian Patton Oswalt, their daughter, Alice, then 7, and a years’ worth of research, interviews and writing on the uncaught serial killer and rapist she dubbed the Golden State Killer.

Known by many monikers, including the East Area Rapist, the Visalia Ransacker, the Original Night Stalker and the Diamond Knot Killer, McNamara believed the man responsible for at least 12 murders, 51 rapes and 120 home burglaries needed a label that fully encapsulated the terror that gripped the entire state of California in the 1970s and ‘80s.

After McNamara’s death, Oswalt enlisted the help of her friends — Billy Jensen, an investigative journalist who focuses on unsolved murders and missing persons, and researcher Paul Haynes — to complete the book.

"I’ll Be Gone in the Dark: One Woman’s Obsessive Search for the Golden State Killer" was released in February and reached the No. 1 spot on The New York Times’ bestseller list last month. It has also been acquired by HBO with plans to adapt it as a docuseries.

Then, just days after the second anniversary of McNamara’s passing, police announced they had found their man. 

Joseph James DeAngelo, 72, was arrested at his Sacramento home Tuesday on a warrant stemming from two of the murders perpetrated by the Golden State Killer. He is scheduled to be arraigned on Friday. 

On Wednesday, officials said DeAngelo, a former police officer, is the Golden State Killer and said DNA evidence ties him to the crimes. 

"You did it, Michelle,” Oswalt proudly proclaimed in an Instagram video Wednesday. 

Sacramento County Sheriff Scott Jones said that while his office had been asked countless times in the past 24 hours if McNamara’s book helped solve the case, "The answer is no."

"It kept interest in tips coming in," Jones said. “Other than that, there was no information extracted from that book that directly led to the apprehension."

But those familiar with McNamara and her work said that interest was a key part in seeing this case solved. 

"Even though the cops are never going to say it, your book helped get this thing closed,” Oswalt posted to his late wife on Twitter.

Oswalt discussed his wife’s work during an appearance on “Late Night with Seth Myers” early Thursday, saying, "Her book and the article that led to the book really amped up all the interest in the case and really put a lot of focus on this.

"Not to discredit the work that the police and the lab technicians did, but... it was her dream," he added. "She always said, 'I don’t care about credit, I want to know that he’s in jail.' And now he’s caught. The bracelets are on, and it feels like this thing that she wanted so badly is now done."

Police closed in on DeAngelo five days before his arrest. They watched his movements at his home for several days and collected a DNA sample from something DeAngelo discarded in that time.

He had not been considered a suspect previously, police said.

Though his name was not among those McNamara considered during her own investigation, the impact her work had on the case was evident, Billy Jensen told CBS News.

"Just the fact that they said the book didn't help but then said, 'We've got the Golden State Killer,' it's a bit contradictory," Jensen said.

After DeAngelo’s DNA came back a match to that of the Golden State Killer, police waited until he walked outside his home to arrest him, Sheriff Jones said.

"He was very surprised by that," Jones said. "It looked as though he might have been searching his mind to execute a particular plan he may have had in mind... but he was not given the opportunity. It happened almost instantly and he was taken into custody without incident at all."

During his interview with Seth Myers, Oswalt read a letter that McNamara had written to the Golden State Killer. The message, titled "A Letter to an Old Man," was used as the Afterword in her book.

"One day soon, you’ll hear a car pull up to your curb, an engine cut out," McNamara wrote. "You’ll hear footsteps coming up your front walk. Like they did for Edward Wayne Edwards, 29 years after he killed Timothy Hack and Kelly Drew, in Sullivan, Wisconsin. Like they did for Kenneth Lee Hicks, 30 years after he killed Lori Billingsley, in Aloha, Oregon. 

"The doorbell rings," McNamara continued. "No side gates are left open. You're long past leaping over a fence. Take one of your hyper, gulping breaths. Clench your teeth. Inch timidly toward the insistent bell. 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."