Of course, the main question now is whether the decryption makes sense. Here’s the ciphertext:


As can be seen, this letter doesn’t look like an encrypted text at all. So, if there is a secret message contained in this text, it must be hidden with a steganographic technique. The Daily News article doesn’t provide any details, it just mentions “a system of letters and numbers”. This means that we can’t check whether Sherwood’s codebreaking makes sense.

Even if Sherwood’s deciphering is correct and if it refers to afore-mentioned Robert Rackstraw, there are serious doubts about this new finding. As far as I know, there is no proof that this letter was really written by Cooper. It only contains information that was available in the press.

According to the Wikipedia article about Dan Cooper, Sherwood has “deciphered” other letters allegedly sent by Cooper before. The details might be given in a TV documentation I haven’t watched yet. Here is a radio report by the same producer:

Apparently, the new decipherment will be covered in an another TV documentary about the Cooper case, which will air in the near future.


Does it make sense?

To be honest, this story about the alleged Cooper decipherments doesn’t look very sound to me. It has probably been made up to promote a series of TV documentaries. I would be surprised if the letter shown above really contains a hidden message.

If you know more about this story, e.g. if you find a text hidden in the above letter, please let me know.

Further reading: The Zodiac Killer code is solved – at least in this new movie

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Kommentare (7)

  1. #1 Klaus Schmeh
    30. Juni 2018

    Karin Isberg via Facebook:
    Very interesting story.

  2. #2 David Oranchak
    30. Juni 2018

    One of several red flags to me:

    “He decoded ;’through good ole Unk’ to mean ‘by skyjacking a jet plane,’ using a system of letters and numbers.”

    Seems likely they forced words to come out using some sort of coincidence generator. Naturally, they won’t show their work, otherwise it would get shot down.

  3. #3 Richard SantaColoma
    30. Juni 2018

    From this quote on Wikipedia, “In January 2018, a small cold case documentary team reported that they had obtained a letter originally written in December 1971 and sent to The New York Times, the Los Angeles Times, The Seattle Times and The Washington Post, with numerous numbers and letters written on it. The team, led by Tom and Dawna Colbert, says that the codes were deciphered and matched to three units Rackstraw was a part of while in the Army…”

    … it sounds as though it is ANOTHER letter, a 1971 letter, with the “numbers and letters written on it”. The letter referred to in the article is from 1972. It would be interesting to see that other letter… is it in print?

  4. #4 Klaus Schmeh
    30. Juni 2018

    @Rich: I haven’t seen this letter yet. Perhaps, it is shown in the TV documentary.

  5. #5 Thomas
    30. Juni 2018

    The other letter(s) from 1971 are shown in the press releases: https://dbcooper.com/2018/06/press-release-smoking-gun-robert-w-rackstraw-sr/ (apparenty the most detailed coverage of the case!)
    The first five letters contain letter and number sequences that represent the Army units in which Rackstraw served during the ear in Vietnam.
    In the release concerning the 6th letter to the Oregon newspaper from 1972, which apparently contains a cipher/code without numbers, it says: “‘Nam superior uses 1950 Army booklet to unmask a 6th note from jumper”. This refers to Rick Sherwood who served in the same unit. There is an Army technical manual on cryptography from 1950, https://archive.org/details/41748889078809, up to now I can’t see if it provides a method used in the letter.

  6. #6 Thomas
    30. Juni 2018

    Rackstraw’s Vietnam commander, retired LTC Ken Overturf (4/25/18): “With the ‘Basic Cryptography’ Army manual now in my possession, we have doctrinal validation of the process that (code-cracker) Rick Sherwood used to decipher all of these messages. In addition, DoD records show Rackstraw learned this coding process at Fort Bragg, North Carolina, in a Special Warfare Operations Course in 1968.”

  7. #7 Thomas
    1. Juli 2018

    ‘Basic Cryptography’ from 1950 seems to contain only conventional transposition and substitution ciphers that yield ciphertexts which are gibberish and as long as the plaintexts. Both is not the case in “through good ole Unk” and “please tell the lackey cops”. What do you think?