It could be argued that the author of the Scorpion letters, which were mailed to John Walsh, presenter of the popular television show America's Most Wanted, was hinting he was once the infamous Zodiac Killer. In a series of cryptograms and letters sent in 1991, the headline text of "Hi, Remember Me" is fairly self-explanatory. To discover whether the Zodiac Killer had reinvented himself as the "Scorpion", let us take a look at the 148 character cipher, the last lengthy code mailed by the Zodiac Killer in May 1971 and see if there are any overlapping features to the longest of the Scorpion ciphers (180 characters).

Disregarding the orientation of the characters, I have noted seven overlapping ciphertext characters from the Z148 to the main Scorpion cipher. Six of these characters (boxed in red below) had never been used by the Zodiac Killer prior to 1971. The ciphertext character "7" represented the plaintext letter "A" in both the Z148 and Albany code. The "sun cross" symbol (similar to crosshairs) and ciphertext character "7" were both present in the Z148, Albany and Scorpion codes. 

​The Zodiac Killer signed off his accompanying letter to the 148 character code in 1971 with a "sun cross" symbol (see below). This represented the plaintext letter "Z" in the Z148.cipher, which meant that Zodiac Killer was effectively signing off with a "Z" in his communication, just as he did in the Halloween card on October 27th 1970.

So I took a gamble and presupposed that the Zodiac Killer, if he composed the Scorpion ciphers, may have used the "sun cross" symbol to represent the plaintext letter "Z" in the main Scorpion cipher. The "sun cross" symbol was only present in the main Scorpion cipher, headed by "Hi, Remember Me". If the plaintext letter "Z" was featured in the main Scorpion cipher, then it held the possibility of the pseudonym "Zodiac" being present. However, to bolster this proposition, we needed at least two repeating ciphertext characters (the same distance apart) within two runs of six consecutive characters of the Scorpion cipher - and they both had to begin with a "sun cross". It was possible. 

It could be argued that the author of the Scorpion letters, which were mailed to John Walsh, presenter of the popular television show America's Most Wanted, was hinting he was once the infamous Zodiac Killer. In a series of cryptograms and letters sent in 1991, the headline text of "Hi, Remember Me" is fairly self-explanatory (see below). The wording used in the correspondence such as "you and your over anxious associates would try and nail me even if I used a P.O. Box for a return address" is interesting, because post office box keys were a feature of the Eureka card just a few months earlier, in 1990. The Atlanta letter, almost certainly mailed by the Zodiac Killer on March 8th 1981, contained the wording "I am not writing in the same hand writing". The Scorpion letters author wrote "My style of hand writing on these cards is very much altered". There is a distinct gap between "hand" and "writing" in both instances (rather than "handwriting" written as one word). The Scorpion letter also stated "I will soon start collecting bodies for you", replacing the word "slaves" used by the Zodiac Killer. 

These complex cryptograms are extremely difficult to solve because of the excessive ciphertext characters used in the encoding process. However, there are some possible openings. The Zodiac Killer mailed a 408 character cipher on July 31st 1969, a 340 character cipher on November 8th 1969, a 38 character cipher on December 7th 1969, a 13 character code on April 20th 1970 and a 32 character code on June 26th 1970, but not once did he use the "sun cross" or "number 7" as a ciphertext character. The 148 character cipher mailed to the San Francisco Chronicle by the Zodiac Killer sometime in May 1971, the 50 character cipher mailed to the Albany Times Union newspaper on August 1st 1973, and the 180 character Scorpion cipher mailed in 1991 (all bearing traits of the Zodiac Killer and not contemporarily published in the newspapers), all contained the "sun cross" and "number 7" as a ciphertext character. ​The "number 7" in the 1971 and 1973 ciphers, both decoded to the plaintext letter "A".

In the 148 character cipher mailed in 1971, the Zodiac Killer used the "sun cross" as a signature rather than his traditional crosshairs - thereby signing off his communication with the letter "Z" - because the "sun cross" descoded to the plaintext letter "Z" in the 148 character cipher. Bearing in mind that the Scorpion letter author headlined with the wording "Hi, Remember Me", it had to be considered that the pseudonym "Zodiac" may have been hidden somewhere in the cryptogram. Since the Zodiac Killer probably used the "sun cross" to represent the letter "Z" in the 148 character cipher, I took a look at the 180 character Scorpion cipher to see if any repeating ciphertext characters would mimic the pseudonym "Zodiac", using the "sun cross" to represent the plaintext letter "Z". Below are the examples I found beginning on row 2 and 14. To view the Scorpion letters and ciphers, please visit Science Blogs. 

Beginning in 1991, John Walsh from the popular television show America's Most Wanted, started receiving a sequence of sinister letters and cryptograms that many have considered may have been authored by the infamous Zodiac Killer. The title of the fifth Scorpion cipher stated "Hi!, Remember me?", and was accompanied by a 180 character cryptogram. The implication being, we were supposed to infer it may have been the Zodiac Killer. But was it? The cryptogram had 155 unique characters, meaning any conventional technique of breaking this mystery was nigh on impossible. So I decided to take a look at previous Zodiac Killer encipherments and examine if any correlation exists between the Scorpion cipher and his solved cryptograms. In previous articles (visit links provided) a case has been presented to show that the 148 character cryptogram mailed in 1971 and the Albany letter mailed in 1973 are likely connected, as well as the 340 character cipher and 148 character cipher. [1] [2]. But let's take a look at the 148 character cipher and fifth Scorpion cipher. Below is the solved 148 character cipher, followed by the accompanying text that came with this communication.

This communication was signed with a "sun cross" rather than the usual Zodiac crosshairs, leading some to believe it was an obvious hoaxer. However, somebody prepared to mail a Zodiac communication complete with a 148 character cipher, is hardly likely to be ignorant of the Zodiac Killer crosshairs that adorned virtually every single communication mailed by the Bay Area murderer. This "sun cross" signature on the letter was also present in the cryptogram, in which it was determined to represent the letter "Z". Therefore, the author of this letter likely signed off with the letter "Z" to represent the "Zodiac", as he had done in the Halloween card on October 27th 1970. It was probably a clue to begin the decoding of the 148 character cipher. When the letter "Z" was used for the "sun cross" in the cipher, the inevitable phrase of "Zodiac Speaking" is revealed (see above). The "sun cross" is also twice present in the 180 character Scorpion cipher. If you take a look at the bottom of the 180 character cipher, the letter "Z" applied to the "sun cross" allows "Zodiac Speaking" to conveniently end the cryptogram. There is even room to place "The Zodiac Speaking" before the repeated letter "N" prevents further progress.       

The 148 character cipher had not been released into the public domain by the time the Scorpion ciphers arrived, but I have highlighted with a blue square the five symbols used in the Scorpion cipher that look eerily similar (and the same) as the 148 character cipher. The number "7" in both the 148 character cipher and Albany communications represented the letter "A". It is present in the Scorpion cipher also. Could the Zodiac Killer have teased us with the introduction of "Hi, Remember Me" and finished the message with "This is again the Zodiac speaking"?

Here are the other parts of the Scorpion cipher communications released Science Blogs.