One of the best finds in recent years was by Tahoe27, a regular contributor to the Zodiac Killer Site forum, who in December 2013 discovered a connection between a Tim Holt comic and the October 27th 1970 Halloween card. Many features on the cover of the comic parallel the Halloween card, including the wording By Fire, By Gun, By Rope and By Knife, along with "Redmask" (the skeleton eyes) and "Lady Doom" (peek-a-boo you are doomed). However, I believe Tahoe27 is not convinced that the Halloween card was authored by the Zodiac Killer. If the Halloween card was authored by an impostor, who based the Halloween card on issue 30 of the Tim Holt comic, then are we to believe he was extremely fortunate that a year earlier, the real Zodiac Killer just happened to create a 340 cipher containing the word "BY" in all four quadrants of the cipher, along with PARADICE and SLAVES being a possibility, running vertically and horizontally along the midpoint of the cipher, just like the configuration on the Halloween card.
Admittedly, the words paradice and slaves have not been proven as the intention by the Zodiac Killer in the 340 cipher, but the fact they are a distinct possibility when we draw a comparison to the Halloween card, appears another very fortunate stroke of luck - particularly if we believe the author of the Halloween card wasn't the Zodiac Killer - and only considered the Tim Holt comic in his design of the Halloween card. If the Halloween card was crafted by the Zodiac Killer using only the Tim Holt comic, then the above still applies. The more likely conclusion we could draw from this, is that the 340 cipher was designed with the Tim Holt comic in mind, and the Halloween card mailed one year later was giving us a clue.
If this wasn't the intended design of the 340 cipher, then either the Zodiac Killer or an impostor got extremely lucky in just happening upon a Tim Holt comic that mirrored the 340 cipher unintentionally. But we may just be able to prove a definite link between these two communications and confidently state that both were designed by the Zodiac Killer - and with a fair degree of confidence argue that the 340 cipher is not a cipher in the true sense of the word. The majority of the characters likely filler, but in this instance, far more than the 18 characters at the foot of the 408 cipher. The reason we may be able to argue that the 340 cipher is not a continuous and uniform message like the 408 cipher (and not a cipher as we believe one to be), is because the Zodiac Killer lined us up for a fall and then admitted to it a year later.
On the 'Dripping Pen' card accompanying the 340 cipher, the killer stated
"This is the Zodiac speaking. I though you would nead a good laugh before you hear the bad news. You won't get the news for a while yet. Could you print this new cipher in your frunt page? I get aufully lonely when I am ignored, so lonely I could do my Thing". Was that bad news to come on October 27th 1970 when he mailed the Halloween card. If we believe that the Halloween card design is referring back to the 340 cipher, then the message concealed on the envelope inner of "sorry no cipher" is the Zodiac Killer finally admitting that the 340 cipher is not the real cipher we had thought. He is apologizing and declaring that the 340 is "no cipher", but is primarily based upon the paradice and slaves configuration. This is why he crosses the phrase "sorry no cipher" to mimic the design of paradice and slaves, using 13 letters in both instances. The Zodiac Killer could easily have written "sorry no cipher" just the once, but deliberately fashioned it to form a link between the Halloween card design and the 340 cipher.
After searching for solutions to the 340 cipher for nearly half a century, the Zodiac Killer may have given us the answer to its design after just one year, but sadly it was overlooked. We have took the phrase "sorry no cipher" as an apology that he wasn't giving us a cipher in the Halloween card, when in actual fact, he was apologizing for stringing us along for the best part of a year, before finally offering us the real solution to the 340 cipher on October 27th 1970, contained within the Halloween card. You could say it was a "trick" and "treat" befitting of Halloween. However, there is still a little more to find regarding the methods of death and how they configure within the 340 itself - so the search is not over yet.
ZODIAC ADMITTED 340 NOT A REAL CIPHER [PT2]
ZODIAC ADMITTED 340 NOT A REAL CIPHER [PT3]
Cipher Explorer tool below, courtesy of Zodiac Killer Ciphers.