The Zodiac Revisited: The Facts of the CaseUnderstand History's Most Enigmatic Serial Killer In December of 1968, a serial killer began orchestrating a campaign of terror in the San Francisco Bay Area. Not satisfied with the simple act of murder, he taunted law enforcement and the public by writing letters to local newspapers. Through often cryptic and bizarre content including four ciphers, three (now two) of which have never been solved the psychopath played a twisted game. Reporters dubbed