A few years after the Zodiac murders, an unknown person sent a letter to an address in Albany, NY, claiming that he was the Zodiac Killer and that he intended to start killing again. A few lines of this letter are encrypted. The cleartext is unknown.
The TV documentary The Hunt for The Zodiac Killer, which aired a few weeks ago, has aroused a lot of new interest in the Zodiac Killer case. As mentioned in a recent blog post, there were at least ten Zodiac Killer copycats, who sent Zodiac-style encrypted messages to the police or newspapers. Some of the anonymous senders claimed to be the real Zodiac Killer, others just imitated the killer’s way of writing or encrypting. Some of the Zodiac copycat messages were solved, others weren’t. As far as I know, none of these letters could ever be linked to the Zodiac murders or another crime.
The Albany letter
One of the unsolved Zodiac copycat messages was sent to the Times Union, a daily regional newspaper published in Albany, the capital of New York State:
As can be seen, this letter was stamped on August 1, 1973, four years after the last confirmed Zodiac murder and three years after the last known encrypted Zodiac message.
The author of the Albany letter claims to be the Zodiac Killer. He writes:
YOU WERE WRONG I AM NOT DEAD OR IN THE HOSPITAL I AM ALIVE AND WELL AND IM GOING TO START KILLING AGAIN
Below IS THE NAME AND LOCATION OF MY NEXT VICTIM
But you had Better hurry because I’m going to kill Her August 10th at 5:00 P.M. when the shift change. ALBANY IS A NICE TOWN.
To my knowledge, there was no crime on August 10, 1973, that might be the one the writer of these lines announced. There is no real evidence that he is identical with the Zodiac Killer.
Here’s the encrypted part of the letter:
This cryptogram consists of 50 characters. Here’s my transcription (some of the letters are hard to read):
Here’s a frequency analysis made with CrypTool 2:
A ciphertext of this length is usually long enough to be broken by freqency analysis or hill climbing. Nevertheless, nobody has been successful in deciphering the Albany message to date.
Can a reader solve this 45-year-old crypto mystery?
Further reading: The Zodiac Killer code is solved – at least in this new movie