He received his name after he scribbled zodiac signs around several of his victims. The rare survivors from his attacks have described him as a heavy set man with glasses and red hair. There are numerous theories surrounding his identity, methods, and his reasoning behind the astrological murders. His numbers vary according to sources. Some attribute only six hits to this faceless maniac. Others believe the Zodiac has slayed up to 49 individuals. Some have settled on 37 after a note he sent to a San Francisco paper on January 30, 1974 in which he wrote "Me-37 - SFPD-0."

The absolutely most fascinating thing is the letters he sent in code to police and newspapers, some were deciphered but most weren't. He sent twenty-one letters to various newspapers boasting of his crimes. His envelopes were easy to recognize, always with double postage and the writing "please rush to editor.".

This letter here has defied the most sophisticated codebreakers and computers at the CIA, NSA and FBI. although it could have been just a joke from the "Zodiac", much points to that it wasn't. He made his own code and no-one has been able to decipher it yet. The code in this letter was built up around 340 symbols, One thing that indicates that it wasn't a hoax is that in this letter on the sixth line he made a correction. Why would he do that if it had no meaning ? He could just have left it as it was.