I'll Be Gone in the Dark season 1 episode 1
Episode title: Murder Habit
Delving into the world of online chat rooms and crime blogs, writer Michelle McNamara becomes immersed in the graphic details of the Golden State Killer case, connecting with like-minded sleuths, trading facts, photos and leads. After pitching a story to Los Angeles Magazine, she hits the ground running, interviewing several EAR survivors and retired detectives who worked the case.
