THE ZODIAC KILLER
| PERIOD | Confirmed attacks December 1968 – October 1969 |
| VICTIMS | Five killed, two survived (confirmed); the killer claimed 37 |
| JURISDICTIONS | Vallejo PD, Napa County, San Francisco PD, Solano County |
| STATUS | Never identified; the SFPD case remains open |
THE CLAIM
A murderer who courted the press under a trade name, mailed cryptograms to newspapers with demands that they be printed, and was never caught — despite surviving witnesses, a police sketch, handwriting, and half a century of professional and amateur pursuit.
WHAT IS KNOWN
The confirmed series is short and concentrated. In December 1968 a young couple was shot on Lake Herman Road outside Vallejo. In July 1969 a second couple was shot in a Vallejo parking lot; the man survived. That August, letters arrived at three Bay Area newspapers, each carrying a third of a 408-character cipher and details only the shooter could know. In September 1969 a hooded man stabbed a couple at Lake Berryessa — the man survived — and in October the killer shot cab driver Paul Stine in San Francisco's Presidio Heights, mailing a piece of Stine's shirt to the San Francisco Chronicle as proof of authorship. Letters, some credible and some not, continued into the 1970s.
The ciphers became the case's signature. The 408 was cracked within a week — by a schoolteacher and his wife, not a government agency — and revealed a rambling statement about collecting slaves for the afterlife. The 340-character cipher mailed in November 1969 resisted every attack for 51 years, until December 2020, when a private team — David Oranchak, Sam Blake, and Jarl Van Eycke — solved it with custom software; the FBI confirmed the solution. It contained taunts ("I am not afraid of the gas chamber") and, to no one's real surprise, no name.
The most-investigated suspect was Arthur Leigh Allen, a Vallejo man searched and scrutinized for decades and never charged; he died in 1992, and a partial DNA profile later developed from letter stamps did not match him. A 2021 media claim naming a different deceased man was promptly dismissed by the FBI and local agencies as unsupported.
LEADING THEORIES
- Allen, despite the DNA. Case researchers who favor Allen note the circumstantial file against him was the thickest ever assembled and argue the stamp DNA may not be the killer's. Skeptics reply that decades of scrutiny produced nothing chargeable — which is the point.
- An unknown local with cryptographic hobbyism. The solved ciphers show homemade, error-prone construction — an amateur with patience, not a trained hand. Consistent with a man who read the right paperbacks, not a professional.
- A shorter career than claimed. His count of 37 victims is generally regarded as bluster; most researchers hold to the five confirmed dead, with the earlier 1966 Riverside murder of Cheri Jo Bates — long floated as a Zodiac precursor — discounted by Riverside police in 2021.
- Genetic genealogy will end it. The technique that identified the Golden State Killer in 2018 is the case's best remaining hope, if surviving evidence yields a usable profile.
ASSESSMENT
The Zodiac's actual body of work was brief; his body of correspondence made him immortal, which was plainly the idea. The 2020 cipher solution demonstrated two things: that the answer to a fifty-year question can arrive from three hobbyists on two continents, and that the killer never intended his puzzles to identify him. The OSA expects this file to close the way modern cold cases close — in a lab, quietly — or not at all.