Unsolved Crime

🇺🇸 United StatesThe Zodiac Killer

Benicia–Vallejo–San Francisco Bay Area, United StatesView on map1969Unsolved
Evidence strength

The Story

Between 1968 and 1969, a killer attacked couples in the San Francisco Bay Area, killing five confirmed victims. The assailant mailed letters to newspapers claiming responsibility, including ciphers. Partial codes were solved; the 340-character cipher was cracked in 2020, but the killer's identity remains unknown.

Images

Timeline

  1. The first confirmed Zodiac double shooting occurs on Lake Herman Road.

  2. A second shooting at Blue Rock Springs Park kills one victim and wounds another.

  3. Taxicab driver Paul Stine is murdered in San Francisco; a partial license plate is reported.

Known Evidence

Evidence strength

How well-documented and physically verified the case evidence is.

  • Ballistic links between the Lake Herman Road, Blue Rock Springs, and Presidio Heights shootings.
  • Zodiac's own letters, postmarks, and partially solved ciphers sent to San Francisco newspapers.
  • Survivor testimony from the Stine shooting and the Berryessa attack.
  • 2020 decryption of the 340-character cipher by private codebreakers, verified by the FBI.

Unresolved

What We Still Don't Know

  • The killer's true identity and whether they committed additional unlinked homicides.
  • The full meaning of remaining unsolved Zodiac ciphers.
  • Whether Arthur Leigh Allen or other named suspects can be conclusively tied to the crimes.

Hypotheses

Theories

Ranked by plausibility — highest first.

Most plausible
Plausibility

Local Bay Area Offender

The killer lived or worked in the East Bay or North Bay, selecting victims near familiar roads and mailing letters from public post boxes.

Theory 2
Plausibility

Expanded Victim Count

Zodiac may be responsible for additional unsolved homicides across California beyond the five confirmed cases.

Nearby on the map

Related Mysteries

Sources