Michelle McNamara, a true crime writer married to comedian and actor Patton Oswalt, passed away in her sleep in April 2016.
After her death, Oswalt wrote, "I was looking forward to spending my life with the single most original mind I'd ever encountered. And now? Gone. All gone."
On Friday, Oswalt has confirmed to the Associated Press that an undiagnosed heart condition, combined with prescription medication, proved to be lethal.
"I loved her," Oswalt wrote. "This is the first time I’ve been able to use 'I' writing this. Probably because there hasn’t been much of an 'I' since the morning of April 21. There probably won’t be for a while. Whatever there is belongs to my daughter—to our daughter. Alice."
"She left Alice, her 7 year-old daughter. But not before putting the best parts of her into Alice, like beautiful music burned onto a CD and sent out into the void on a spaceship," Oswalt wrote.