Thomas Horan has published a short ebook entitled The Great Zodiac Hoax of 1969. The current version of the book is heavily redacted starting from, approximately, the two-thirds point. Supposedly, a less-redacted and otherwise augmented version of the book will be made available in the future.
The fundamental premise of Horan's book challenges the most basic, seemingly self-evident, assumption in the case of the Zodiac: that the killer even existed.
While I appreciate the general idea of questioning all that is known and accepted, I must be honest and point out that I find little value in Horan's arguments. In my estimation, they simply are not compelling.
It's tempting to address the contents of Horan's book in a reasonably thorough manner. However, it's impossible for me to conclude that doing so would amount to anything more than a waste of time. Clearly, as is the case with so many other Zodiac-Killer theorists, there is nothing I (or anyone else) can say that would change Horan's mind regarding his beliefs. Furthermore, I don't know of a single person besides Horan who finds his theory compelling (if you are someone who is swayed by Horan's arguments, please say so in the comments). Hence, any time and effort invested in discussing and/or refuting Horan's reasoning will have a net value of nada. Since time is an especially valuable commodity, I choose to spend mine elsewhere. In fact, I already regret the amount of time I've spent on this book...
Add to this the argumentative and antagonistic style Horan uses when responding to legitimate questions about his positions (simply see the comments from this post), and my desire to do anything to help the author all but evaporates.
The best thing I can say about the book is that it's relatively short and inexpensive. If you agree with observations such as the ones below (all of which are taken from the book, in essence), you may find it worth reading. Otherwise, I'd advise you to spend your time elsewhere.
- During the calls to police following the attacks at Blue Rock Springs and Lake Berryessa, the fact that the caller did not say "This is the Zodiac speaking" is strong evidence that the caller was not the Zodiac.
- The failure of Bryan Hartnell and Cecelia Shepard's assailant to verbally identify himself as the Zodiac suggests he was not the Zodiac.
- It's a reasonable possibility that a person who was not the attacker but was the letter writer wrote on Bryan Hartnell's car door following the attack at Lake Berryessa.
- The fact that the Stine letter describes the location of the crime scene as "by Washington St. + Maple St." is a clear indication that the letter writer did not know the location of the crime scene and was not the murderer.
I'll also note that the editing of Horan's book leaves something to be desired as well. There are spelling mistakes and factual errors. As an example of the latter, Horan describes the first three letters sent by the Zodiac (whoops, did I just say that?) as "...three verbatim copies of one text." Of course, that's incorrect. The three were similar, but there were important differences - the most significant of which is that the letter to the Chronicle was the only one of the three to include the sentence: "In this cipher is my idenity (sic)."
Normally, I would give somebody a pass on this type of stuff. But, Horan has been screaming at the top of his lungs that he's the only one who's bothered to actually read the relevant documents (blah, blah, blah) and he's been insulting people who have made significant and meaningful contributions to the status of the case. Therefore, I see no reason to give him a pass on anything.
I'll close by recollecting something that my seventh-grade science teacher used to say: "When the whole world looks crazy, it's time to look at yourself." Thomas Horan, I'm guessing the whole world is looking crazy...