The following are valuable internet resources regarding the case of the Zodiac.

  • ZodiacKiller.com
    • Tom Voigt's website on the Zodiac has been around for over a decade and contains a massive collection of information related to the case. Since I have little inclination to duplicate information that's adequately provided elsewhere, I often refer to ZodiacKiller.com.
  • ZodiacKillerCiphers.com
    • Long-time Zodiac-Killer cipher enthusiast doranchak (as he's most commonly known) has put together an impressive site of tools, resources, observations, and commentary related to all aspects of the Zodiac Killer's ciphers. If nothing else, check out the always-popular webtoy application and try your hand at solving the 340.
  • ZodiacKillerSite.com
    • A newly revamped Zodiac-Killer forum run by long-time community contributor Morf13.
  • zkdecrypto
    • An open-source cryptanalysis program capable of solving the Zodiac Killer's 408 cipher.
  • The Zodiac Killer File at the FBI's "Vault" Site ( Packet 1 2 3 4 5 6 )
    • In the 90's, the FBI disclosed hundreds of pages of information regarding the case of the Zodiac. Later, they made the same information available on their website in an FOIA area they used to call the Electronic Reading Room. They've since revamped the area and rebranded it "the Vault." Here is the FBI's summary of the file on the Zodiac.
  • The San Francisco Chronicle's Zodiac Killer Page
    • sfgate.com is the online arm of the San Francisco Chronicle newspaper - the recipient most often preferred by the Zodiac during his letter-writing campaign. Not surprisingly, the newspaper has a section dedicated to the events surrounding the case of the Zodiac. Particular items of interest include a handful of the numerous Chronicle articles written about the killer.