HBO has released the first trailer for its new six-part documentary series I'll Be Gone in the Dark, which follows the hunt for the Golden State Killer. The series is based on the book of the same name by crime writer Michelle McNamara, and it explores her investigation into the dark world of a violent predator who terrorized California in the '70s and '80s. The Golden State Killer, as she dubbed him, is responsible for 50 home-invasion rapes and 12 murders. The series aims to give voice to the survivors and their families, documenting an era when …