Z32 Solution

This is a possible Z32 solution.  I am not a cryptographer nor a detective, but I do work in the sciences and typically go by the mantra that the simplest answer is probably the right answer.

This solution is not complex, but determining the intent 50+ years later is rather complex.

Like many people, I wonder if the killer was pointing at an actual "bus bomb", where he lived, or something else.

Here is the Z32 letter:

...and the map:

The key thing to solve is this:

Looking at the map, I noticed that he created his own system of coordinates and points out that 0 is to be set to magnetic north.  I looked up magnetic north for the Walnut Creek area in 1970, and it was 17° east of north.

Since the map states that 0 was to be set to magnetic north means he probably went up to the top of Mt. Diablo and could see the item he is referencing or at least some type of reference on the map.

I also noticed there were only 3 repeating characters.

With 32 characters and only 3 repeats, I figured this is not a substitution cryptogram, but that it has to be something else.

Remembering the map and that it has the 0-3-6-9 "clock", I thought I was looking for a direction and a distance from Mt. Diablo.  I also noticed two distinct symbols that seemed like radians and location.  The O with a dot in it reminds me of the "clock" and the angle of a circle.  The circle with the cross-hairs leads me to believe it is position.

So, now there are two symbols in the thirty-two character code.  That leaves 30 letters left.  Since the map "radians" only go up to 12 (or back to zero) and the radian symbol is the 19th symbol, something seems amiss.  Also, the cross-hairs is the 29th symbol.

When I first looked at the Z32 code, I saw the word CALIFORNIA in the first part of the code.  I am not the only one to see this, so the killer put just enough into the code to make the first 10 letters look like the word "CALIFORNIA."

I think the killer wanted a 10 digit scale to use, and the word "CALIFORNIA" has 10 letters.  I believe that was his scale.  Imagine then using the CALIFORNIA scale to see where the "dot circle" and cross-hairs fall in the 10 scale.

The dot-circle falls at the 9th position and the cross-hairs at the 8th position.  I think the solution is a direction of 9 according to the map and 8 miles from Mt. Diablo.

I know the killer sent a follow up note saying it was radians and # of inches, but I think he might have been providing a partial clue or just fucking with us.  Also, it almost looks like the killer made a mistake when writing "# of inches" so did he first start to write "miles" and decided that would be too easy?

If I used inches, it puts the target too far away from Mt. Diablo and the target would not be visible.

Realizing that magnetic north was 17° east of north, I angled the "9" direction 17° up from west and then drew a line 8 miles from Mt. Diablo.

I could not find any schools that existed near that point in 1970.  There is a Walnut Creek middle school nearby and a number of private schools.  Because the direction system of the map is based on a clock, that means each number covers 30°, which means there could be some tolerance to the direction, and ±0.5 miles on distance.

There are a number of schools that fall within this swath of the map.  I also decided to plot this on the original map to see if I was missing something.  When I did this, something seemed off.  Both the angle and distance are in similar, but different, positions.  This made me wonder if the Phillips 66 map had the correct true north and if the scale is off from our more accurate modern tools.

Sure enough, I found that the Phillips 66 map was not set for due north.  In fact, it is about 5° off from north.  This doesn't matter, though, because the killer used his compass to find the "9" direction.

I then decided to use the "9" direction with magnetic north and the scale from the Phillips 66 map.  This is where things get interesting.  The scale on the Phillips 66 map shows that 8 miles is just across I-680.  If the correct direction is extended to be just across I-680, this is the refined target area.

Zooming in:

Here is a zoomed-in look at this area:

Two things come to mind for me in this area.

First, the southbound on-ramp to I-680 from Treat/Geary fits the southbound direction of the "bus" with a sloped hillside right next to it.  It is marked below with an X.

Here is a view of the on-ramp from Google street view for the year 2020:

Here is a view of the on-ramp from Google street view for the year 2011:

In another letter, the killer mentioned that the police wouldn't know if he had an actual "bus bomb" or if it was in his basement.  Basements are a rarity in the Bay Area, so I think the killer was really F'ing with the police.  I don't think there was an actual bus bomb.

So, if it wasn't a bus bomb, what else could there be?

Well, I did some digging and there was a girl named Elaine Davis that was abducted from 158 Pioneer Ave in Walnut Creek on December 1, 1969.  It was a tragic murder and the police subsequently bungled up the investigation.  Here is her location on the map marked by the X:

The girl was abducted in a small window of time late at night when Elaine's mother went to pick up Elaine's father from work.  Elaine was watching her younger sister while both parents were away.

Initially, there was little evidence.  Then a shoe was found along a freeway.  Just over two weeks later, they found a button from her coat in the backyard.  Her coat was found along Highway 17 between San Jose and Santa Cruz just two days after her disappearance, but not connected to the crime for over two weeks.

Almost three weeks after the abduction, a body was found on a beach in Santa Cruz.  Santa Cruz County sheriff's department said the body was of a female over 25 years of age and they had no way of identifying who she was.  Walnut Creek police ruled out the body being that of Elaine Davis.

It wasn't until 2001 that the police were finally able to identify the Santa Cruz beach body as that of Elaine Davis.

So, why do I think the Zodiac Killer is pointing to Elaine? 

In an April 28, 1970 greeting card sent to the SF Chronicle, the killer wrote that he wanted to see people wearing "some nice Zodiac buttons."

 

 

In the Z32 letter (top of this page), he says, "They have not complied with my wishes for them to wear some nice [zodiac] buttons."

Twice he mentions "buttons," which seems rather odd.  I simply think that he is referring to the button that fell off Elaine's coat when she was abducted.

Some online sites mention that there may have been a blue car tailing Elaine in the weeks prior to her abduction.  There are also similar stories of another young woman being tailed by a blue car that was following her while she rode her bus to school.

Was the killer following Elaine?  Did he watch her ride a bus?  Was she a "bombshell"?  Did he call her the "bus bomb" because she rode a bus and was attractive?  The answers to these questions are unknown, but the "button" letters bear a resemblance to the Elaine Davis abduction.

Unfortunately, we will probably never have an answer for the Z32, but this seems like a reasonable and simple solution.