Help catch one of California's most violent killers

At L.A. Magazine, Michelle McNamara reports that one of the most violent serial rapists and killers in history may still be out there.

In the March issue of Los Angeles magazine, true crime writer Michelle McNamara tracks the unsettling and largely unknown backstory of the Golden State Killer and what has prompted authorities to reheat a cold case. He's a criminal whose identity has stumped authorities for decades … Now, thanks to a few key pieces of evidence published for the first time in Los Angeles magazine, authorities believe they might be a clue or two away from cracking the case—and they need your help.

Phone calls to his victims were a big part of the Golden State Killer's M.O., McNamara reports, and the embedded recording [NSFW and disturbing] above is one of the newly-released examples: "Sacramento detectives put a tap on one rape victim's phone. In January 1978, the tap recorded a terrifying, obscene phone call. As the young woman waited silently on the phone, knowing the police tap was recording, the caller breathed heavily, then whispered menacingly. "Gonna kill you," he repeated. "Bitch," he hissed. "Whore." Both the victim and the police believe the caller was the Golden State Killer."