Before Patton Oswalt’s wife, Michelle McNamara, died in her sleep in 2016, she was a writer specializing in true-crime reporting. At the time of her death, she was working on a book about the Golden State Killer, a man who had murdered 12 people and raped 45 throughout California over the course of a decade back in the late 1970s and early 1980s. McNamara had told friends that she felt she was close to solving the case, and now 48 Hours is airing a special called The Golden State Killer about the mystery man and the woman who tried to sleuth out his identity. People who knew the victims, McNamara’s friends, and Oswalt himself all contribute to the report, set to air on April 22 at 10 p.m.