Patton Oswalt, Seth Meyers
Screenshot: Late Night With Seth Meyers

Booked to promote his beleaguered turn as A.P. Bio’s “authority figure with no authority” Principal Durbin, Patton Oswalt instead spent much of his time on Wednesday’s Late Night telling Seth Meyers about a killer. On the same day that authorities revealed they had arrested Joseph James DeAngelo as the notorious Golden State Killer/East Area Rapist, who terrorized California in the 1970s, Oswalt honored his commitment to appear on Late Night with the sort of frazzled, complicated excitement that anyone familiar with his connection to the case will well understand.

Oswalt’s late wife, the crime writer and investigator Michelle McNamara, had spent years pursuing the unknown serial killer and rapist before her unexpected death in 2016. Oswalt, despite being “neck-deep in grief” coping with McNamara’s dying and his new life as a single father, finished the book McNamara had been writing about the case, the gripping true crime tale I’ll Be Gone In The Dark. Posthumously published earlier this year, the book—completed by Oswalt and GSK investigators Billy Jensen and Paul Haynes—concluded with McNamara’s vision of a day that, for the 72-year-old former cop DeAngelo, came true on Wednesday with vivid prescience. Read by Oswalt on Late Night, McNamara’s afterward to the book concludes:

The doorbell rings. 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.

For Oswalt, this perhaps concluding chapter in McNamara’s relentless hunt for a man who left nothing but fear, pain, and death as his legacy, comes with mixed emotions. To Meyers’ thanks for “spending a crazy day with us,” the sleep-deprived but relieved Oswalt responded that, now that DeAngelo—charged with a pair of murders but linked to dozens of other crimes—is behind bars, “It’s really good news.”