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There have been dozens of suspects put forth over the years.  Out of all of those only one was fingered by a victim, only one had pipe bombs and plans for fuel oil/ fertilizer bombs in his basement.  Arthur Leigh Allen lived just eight miles south of Highway 12 and a little over thirty minutes from the Round Hill Creek Overcrossing.  The location of the bomb and construction of the Z32 tends to strengthen the case against Arthur Leigh Allen.


Way, Way out on a limb observations

I’ve mentioned before that the Zodiac wanted the location described by the Z32 found.  Considering all that I know about the Zodiac, I don’t believe that he did anything more than consider creating a bomb large enough to take out a school bus.  Despite what you have read, the bus bomb would never have worked as drawn.  There are multiple errors in the Zodiac’s bomb schematics.  The bus bomb was the cheese in Zodiac’s mouse trap.  If the Zodiac ever planted a bomb, he planted pipe bombs in the form of a booby trap for whoever solved the Z32 and went to confirm the presence of the bus bomb.  This theory is the foundation for my strong belief that the Zodiac wanted the Z32 solved. 

I sense the Zodiac gets frustrated after the Z32 remained unsolved (‘titwillow, titwillow, titwillow’).  He eventually provided more clues to help solve the location of the bomb.  This helps bolster my assertion that the Z32 was a simple longitude x latitude location.

The last three characters of the Z32 were: P, W, delta.  Could this have stood for ‘Pigs Will Die’?  In reference to my proposal that Zodiac booby trapped the location of the bus bomb?  Perhaps he hoped to kill whoever investigated the bomb location?

Zodiac claims that he dug the bomb back up and stored it in his basement.  Vallejo PD confiscated pipe bombs from Allen’s basement.  Do these bombs show any sign of being buried?  Were there any drawings confiscated that contain the same faults as the Zodiac’s published ‘death machine’?  Were any booby trap triggers confiscated like pressure switches or trip wires?  Does any of the confiscated evidence show signs of being buried along Highway 12?

How many suspects had basements? Basements in California? Zodiac specifically states that the bomb may still be in his basement.

The knowledge of ASCII in 1969 would be limited to a very few people. Some Zodiac suspects were known to have teletype machines in their homes.  Was there any evidence that Allen had a knowledge of ASCII?


I am not claiming that I have completely solved the Z32.  For that matter, the Z408 has not been completely solved either.  Those pesky last 18 characters.   Unless the Zodiac is still alive, we may never know what the Z32’s first four and last three characters mean.   Others may use my methods to generate different viable locations for the bomb.  In fact, I encourage you to try to find a bomb location using variants of my method yourself!


I am certain that the Z32 is a simple longitude x latitude location where the Zodiac in 1970 at the very least contemplated placing a bomb capable of blowing up a bus load of school children.


I would like to thank: Detective Terry Poyser of the Vallejo PD, Officer Steven Trojanowski of the Fairfield PD, Dr Berg-Kirkpatrick, my son Joshua for the drone photos of Round Hill Creek and especially my son Jon for validating my proposed solution and accompanying me to the location. 

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