October 27th, 1969, the following statement was published in the Opinions of the People section of The Vallejo Times Herald. Interestingly, this was published only one month after the Lake Berryessa attacks and one year prior to the exact date the Halloween Card was sent to The San Francisco Chronicle. What’s fascinating about this letter is […]
Category: Zodiac Killer
An investigation into the puzzles left by the Zodiac using ancient, medieval, and modern science.

The following analysis includes five individuals, some of higher education, some British authors, and some publicly accused Zodiac suspects, in an effort to determine which writer or writer’s background most closely aligns with the grammatical features found in the Zodiac letters. The Zodiac Suspect Corpus This corpus includes known documents from three Zodiac suspects and […]

Many speculate that the Zodiac Killer’s logo is a crosshair (Figure 1), given a gun was his weapon of choice, and others think his brand was inspired by a Zodiac watch (Figure 2). But why would both the killer and the watch brand adopt the same emblem? Turns out, there is a very significant astrological […]
A Map-Based Methodology

This article explores the hidden meaning behind the map sent to the press by the Zodiac Killer. Drawing upon clues from his Halloween card and other correspondences, this map unveils a possibility the Zodiac Killer was using a map-based methodology. Overview On June 26th, 1970, the Zodiac Killer sent a letter with his Mount Diablo […]
ArcGIS Mount Diablo Map

AZUnsolved created an ArcGIS to aid Zodiac theorists in deciphering the Z32 cipher using the “radians and number of inches along the radians” clue as well as the “set 0 to Mag N” clue on the map. It includes the killer’s map overlaying a foundation map, an early 1960s topographic map, location of the crime […]