Here is the story: Most people believe it all started in October 30th 1966 in California, when pretty young Cheri Jo Bates was murdered. He had stalked her in her university library and disabled her car while she studied inside. When she couldn't start her car, he approached and offered assistance. They spent over an hour talking in the dark alleyway. Then he killed her. He didn't rape her, or steal her purse. He just killed her. The only clue the police had came in a letter from the Zodiac himself. He didn't call himself Zodiac yet. He didn't sign the first letter at all, but in the letter he made threats against women he saw in his daily life and ended the letter "IT WAS JUST A WARNING. BEWARE...I AM STALKING YOUR GIRLS NOW". The letter was sent to the police and the media. A second letter was then sent, but the police were still no closer to having any realistic suspects. The police had one suspect - an ex-boyfriend who didn't take the break up well. He is still listed as the only firm suspect in Cheri's murder forty years after the event. There is some conjecture whether Cheri really was the first Zodiac victim, but her death certainly fits the pattern.
David Faraday and Betty-Lou Jenson
Now the Zodiac began focusing on young couples in cars. Betty-Lou Jenson, 16, and David Faraday, 17, had the unfortunate luck of being at the wrong place at the wrong time. Parked in David's mother's car in a "lover's lane" area on Lake Herman Road, Benicia, California, Betty-Lou and David were ambushed and shot to death late at night on December 20th 1968. It appears that David was standing near the car when shot, whereas Betty-Lou had made a run for it and was shot five times in the right side of the upper back. The police were baffled - there were no witnesses, no motives and no suspects (Graysmith).Darlene Ferrin and Michael Mageau.
Six months later, on July 4th 1969, he struck again. The victims this time were Darlene Ferrin, 22, and Michael Mageau, 19. They were shot while parked at the Blue Rock Springs Golf Course in Vallejo California. Darlene was killed, but somehow Mike survived despite his injuries. He was able to give a description of the killer to police, but no leads turned up anything useful in their investigation. There were reports that Darlene's husband received a prank phone call later that night - he could hear nothing but breathing/wind.Bryan Hartnell and Cecilia Shepherd.
It was less than three months later when the Zodiac struck again. Bryan Hartnell, 20, and Cecilia Shepherd, 22, were stabbed while spending an afternoon relaxing at Lake Berryessa California, September 27th 1969. During this attack, the killer wore a hood over his head which appeared to be home-made. Bryan survived despite six stab wounds to his back. He was able to describe the killer and the hood, but again police were left baffled.Paul Stine.
The final confirmed Zodiac victim was Paul Stine, a cab driver in San Francisco, two weeks later on October 11th. As a victim he did not fit the pattern - he was 30 years old and not in a lovers lane type area. A square of Paul's shirt had been carefully ripped off, and pieces of the shirt were later mailed to the media to prove that the Zodiac was responsible.
One of the most baffling aspects of the Zodiac case were not only the phone calls he made to the police and families, but more than that it was the letters and cypher he designed which caught media attention. The letters kept arriving for years after the confirmed killings stopped - 1974 or 1978 depending on whether you believe the validity of the 1978 letter. It seemed he was desperate to get acknowledgement for his killing. He insisted that his cyphers be published on the front page of newspapers and the media complied. The cypher baffled law enforcement and a civilian couple actually solved it after it was published in the newspaper. The solved cypher, like most of the letters, promised more murders and implied that the Zodiac was always watching. In one letter he even threatened to bomb a school bus, and then shoot the children as they ran off the bus.
With a few appearances over the few years via mail and phone calls, the interest in the Zodiac was maintained, but the case was never solved. Some of the suspects included Ted Kaczynski (The Unabomber) and Bruce Davis (a Manson Family member). The most favoured suspect of many, including author Robert Graysmith, was Arthur Leigh Allen. I say "was" because he died of natural causes in 1992. DNA evidence taken off postage stamps did not match Allen, however there are some claims that he got others to lick his stamps for him. Convincing arguments for and against Allen are all over the interwebs. Other suspects have periodically emerged, as often happens in unsolved crimes. Most recently a woman came forward in 2009 and claimed her late father was the Zodiac.
Realistically the case will probably be filed next to Jack the Ripper and JonBenet Ramsey in the "we are never going to solve this one" drawer. I have just finished reading "Zodiac" by Robert Graysmith. While many have discounted his theories, I found it a useful introduction to the details of the case and it gave me many areas to think about.
The full story can be read on Crime Library and many interesting articles and points of view are out there on the interwebs. I found Zodiackillerfacts and Zodiac Killer most interesting - especially as they seem to have almost opposite views.