Zodiac Killer Ciphers

The Zodiac Killer was a serial killer active in California in the late 1960s and early 1970s. He was never formally identified or charged, though a number of people have since written books and articles claiming to have named him.

There are four main Zodiac Killer Ciphers / cryptograms that are widely believed to have been sent by him:
* Z408 – 31 Jul 1969 – (solved)
* Z340 – 08 Nov 1969 – cipher (unsolved)
* Z13 – 20 Apr 1970 – “my name is” cipher (unsolved)
* Z32 – 26 Jun 1970 – the “map code” cipher (unsolved)

There are also several other ciphers which have been attributed to him (but which seem rather more likely to be hoaxes and/or copycats), most notably:-

* Z148
* Z63

36 thoughts on “Zodiac Killer Ciphers

  1. I3ates on August 7, 2014 at 5:20 am said:

    My name is…… zodiac aka a monument

  2. Richard( Rick) is hinting at Zodiac as being a musician. I met Harry Martin in 2010 and he said he had been misled previously and the real Zodiac was a musician and reporter in Napa. he gave me a name. He said the guys wife had told him one day before she “took a fall”, whatever that means.Harry is dead now, but he was the ears and eyes in Napa for decades. He would know.

  3. Rob: the way that the Zodiac Killer quoted bits from The Mikado certainly makes him seem a little more musical than average, so he could very possibly have been a musician.

    What happened to the wife?

  4. Nickspelling, I completely agree. Everything points to his being a musician, and maybe one who explored the Great American Songbook. He also has/had a penchant for history. He also was a reader, and clearly a writer. Could he have been a journalist and musicians who worked for SF Chron? Maybe as a crime beat reporter? Or one of the other papers associated with the case? I always questioned Pat Stanley’s version of driving by the phone booth on Main Street to see a phone left off the receiver. Who were his associates at the radio station at the time? Could one one them been riding with Pat and “discovered” the phone off the hook, and urged Pat to take credit? The wife took a fall. Thats all i know. I am researching any and all Sf Chron writers and will soon look into any vallejo Napa writers who could be musicians and historians. Whoever the Zodiac is or was had interests that included Norse mythology, crime beats/ fellow journalists, music etc. If he is a crime or court meat reporter, it would make so much sense. I personally think any and all misspelled words were a ruse.

  5. Reading through your work. You have great insights Nick

  6. I will not discuss my work, but suffice it to say I am an investigator.The FBI know far more than they let on. Let me make some very quick declarations,
    hat makes anyone believe that Zodiac was not intentionally leaving false clues? He was known to lie. The first slip up sleuths fall into is believing the Zodiac tells the truth. He wanted to prove he was the killer, but everything else was false, meant to slip up investigators.
    After a number of years of studying the killer, I can determine the following may be true. Note the word may.

    1. The killer probably used a typewriter for his profession. He was driven to write, but sent only hand written messages because nobody would expect him to hand write anything. I believe he may have been a reporter. I believe he may have covered crime or court proceedings.
    The killer may have been exposed to just how we operate when conducting an investigation.If he was a reporter for the Chron or Vallejo Times or Napa Register, he would have had access to police and also access to how other killers make mistakes. If I wrote for a paper, I would have no fear of being monitored, because nobody would expect me to hand write anything. The killer interests include the legal system and journalism. The killer may have been a journalist covering the story, outsmarting everyone because he was both killer and investigator.

    2. The killer wore his hair cut short during an era where long hair dominated youth. This leads me to believe he was employable and conservative. He mentions no “Hippy’ words or rock and roll music. Therefore , his musical likes are Jazz or Classical or both,

    3. The killer mentioned intimate parts of the Mikado, and also an old Norse word. This shows familiarity with history and music. He had education.

    4. The killer wanted to change the world. That was his broad goal.

    5. I expect someone of Norse or German heritage , based on the facial features. A tall man with a slouch. Dead eyes. Smart , but quiet.Purposely misspelled words in order to fool people, and perhaps even finger false suspects.

    6. The killer would have been attracted to the Red Mask comics when he was around age 9-10, and if 1952 is the date of the death by rope, knife, water comic, that would place his birthday at 1942-1943

    7. The killer has probably killed by water and fire and we simply do not know it. If by fire, he would have hidden it well, and probably have been a “watcher” Arsonists have been arrested by us because they return to the scene of the crime.

    8. Tom voight is correct in assuming that the killers handwriting, in combination with DNA matches will solve this case. I highly suggest starting to vet the reporters who were close to the investigation. The Zodiac was, almost certainly, in their midst.

  7. RobLaw on July 14, 2015 at 7:53 pm said:

    It is interesting that many, even in positions of authority are open to, or accepting the fact, that Dr George Hodel was the Black Dahlia killer. One of the most notorious crimes of the 1940’s with a graphic crime scene of Jack the Ripper proportions.

    Now one of the main people behind the pursuit of Dr Hodels guilt was infact his son, Steve, a former NYPD detective.

    What has this to do with the Zodiac killer you may ask? Well, Steve Hodel also claims his father as guilty of those crimes also.

  8. RobLaw on July 14, 2015 at 8:56 pm said:

    I don’t know how much you have looked into previously, but it would be good Nick if you could maybe look into Steve Hodels blog and examine the evidence. I would love to hear a considered view and article from you. It is certainly striking when you see the composite drawing/impression of the Zodiac Killer and images of an older Dr Hodel.

  9. RobLaw on July 14, 2015 at 9:16 pm said:

    One last point for now Nick, my first post tonight was written and awaiting moderation before I saw Robs’ post above me, written literally seconds before.

    It was fascinating to read Robs points, and how easy it would be to match Dr Hodel up to them, he was a musical prodigy as a child, scored 186 on an early I.Q test and ticks many,many boxes for the Zodiac. . Even part 5, the attraction to the Red Mask comics. Rob puts the Zodiacs birth year at 1942-3. Of course this would not match Dr Hodels birth, yet it would his son Steve, who was born November 1941.

  10. Gunnar Johannson on September 8, 2015 at 6:49 am said:

    Idk just bringing up this up since I seen a post that said the Zodiac killer might be a musician, Maybe he was an army officer’s kid and he was an early mind control test at the Presidio(Major Michael Aquino ,Satanist, temple of set founder) that got jealous he couldn’t go on to hit it big like the (other?) Laurel Canyon kids of the army and navy that went on to be big musicians The doors, Crosby, stills nash and others on the “hippie and drug and music scene” In my mind I think his last message on the Radians being +/- along the radians is him trying to throw everyone off because his first message of the map is correct and he was told by his handlers to stop and quit messing with program, he got payed off or they killed him. Lots of Satanism and lucies and such involved. Manson murders happened that area to. idk just speculation.

  11. Rick A. Roberts on December 10, 2015 at 8:51 am said:

    I have been working on deciphering the Z340 CIPHER. Here is what I have came up with. The code deciphers to, ” SVEHGTNEIADENEWTSIE “. The message is, ” SEVEN IN HUNTINGTON DIE AND I WASTED THEM “.

  12. Rick A. Roberts on December 11, 2015 at 10:36 pm said:

    I’ve done extensive work on the Zodiac Killer Ciphers. Here is something that I thought you might want to look at. The Post Card Cipher reads on the left side the following; First line reads in cipher; ” Circle Outline with Centered Cross, R, O, Square with right side diagonally filled in, + “, or ” DGNLE “, ” GLENDALE “. The second line reads, ” Backwards D, I, V, Circle with line horizontally through it, Y, Square Filled In, Backwards L, Backwards P “, or ” OTBHULAE “, ” BOTH ULAE “. ULAE(Universal Limited Art Editions) was a fine art publishing company established in 1957 in San Francisco. Was it the company who made the postcard(s)? The third line of cipher is, “I, Z, Y, +, F, B, I, >, Backwards C, + “, or ” TEUESLTEVE “, or ” LIEUT(LIEUTENANT) STEVE “. Could this be the Steve Hodel who was a LAPD Homicide Detective at that time and stated that his dad was the Zodiac Killer? The fourth line of cipher reads, ” O, , Filled in Circle, F, B, Triangle with period in center of it “, or ” NNUTETS, LA “, ” SUNSET, LA “. Sunset LA was known as Old Sunset at that time and is near Hazelton.

  13. Rick A. Roberts on December 11, 2015 at 10:47 pm said:

    The right side of the post card reads as follows; first line of cipher is, ” Y, Square Outline, Circle with left side vertically filled in, M “, or ” UYIH “, ” HI YU ” or ” HI YOU “. Second line of cipher is, ” M, Backwards D, Circle with cross centered in it, Triangle outline, M, Backwards p “, or ” HODIHE “, ” HI DE HO “. Third line of cipher is, ” I, Q “, or ” TM “. This could mean ” EMPTY “,or ” MT ” for ” Mount ” or ” Mountain “. Fourth line cipher is, ” Circle outline with centered cross, R, O, Square with right diagonal side filled in, + “, or ” DGNLE “, ” GLENDALE “. Last line of cipher reads, ” Backwards D, I, V, Circle with line horizontally through center of it, Y, Square filled in, Backwards L, Backwards P “, or ” BOTH ULAE “.

  14. Rick A. Roberts on December 19, 2015 at 6:55 am said:

    The ” MY NAME IS __ ” Cipher. The cipher reads, ” A, E, N, Circle Outline with Cross Centered in it, Circle Outline with ” 8 ” Centered in it “, K, Circle Outline with ” 8 ” Centered in it, M, Circle outline with ” 8 ” centered in it, Perpendicular sign, N, T, H “. This deciphers to, ” TENDOHLOHHOHINTH “, or ” HOLDEN TOOTH IN TOOTH “. Also, the eighth letter of the alphabet is ” H “. The three eights in the Circle Outlines = ” HHH “. Dr. Hodel’s initials were HHH . His son Steve claimed that his Dad, Dr, Hodel was the Black dahlia Killer and the Zodiac Killer.

  15. Matthew J. Brubach on May 9, 2016 at 2:58 am said:

    The “Harden Decipherment” was probably the biggest setback in the Zodiac investigation. I really feel that anyone who looks at the method used by Harden, and then looks at the decipherment, would also find it laughable. Harden based the decipherment on a belief that the word “Kill” would appear repeatedly throughout the message. He then scanned for double symbols, attributed “LL” to them, and randomly associated letters to symbols to fit a preconceived message that he had in his head.
    – Take the first two lines for instance. Harden claims that it contains 4 I’s, all of which are represented by four seperate symbols. He also claims that there are 5 E’s, all of which are represented by different symbols. That’s completely ridiculous. You can make the argument that it is a Homophonic Cipher if you want, but what method was used by Harden to determine his was the correct decipherment? It’s not the correct decipherment.
    – The fact that there are more symbols than letters in the English language is fairly easily explained, and not by assuming it is a Homophonic Cipher. The symbols are mostly astrological symbols that don’t represent letters. Zodiac repeatedly tried to tell people how to decipher it, but nobody listened (because of Harden). With the “Map” message he wrote in plain lettering “The Mt. Diablo code concerns Radians, and # inches along the radians”. This actually applied to more than the diablo code. Look at the 408 cipher that was supposedly deciphered:
    – The first symbol is a triangle = (trine, 120° radian 2.0944). The next symbol = (Novile, 40° radian 0.698132). The symbol // (Parallel). The thirteenth symbol, looks like a k rotated 90° clockwise = (Quincunx 150° radian 2.61799). The symbol that is a K rotated 90° Counterclockwise =(Semi-Sextile 30° radian 0.523599). The symbol Q = (Quintile 72° radian 1.25664). The symbol “^” = (Vigintile 18° radian 0.314159). The symbol bQ =(Bi-Quintile 144° radian 2.51327). The upside down “T” = (Decile 36° radian 0.628319). The symbol of square with dot in middle = (sesqui-square 135° radian 2.35619). There are many more, the list goes on.
    – We may possibly find out that the Zodiac Killings were the work of more than one person, a collaboration. Possibly of the “Community for Life” Four Pi Movement at the Waller House in SF at the time. Membership included Charles Manson, Manson family members, Dk, some Gypsy Jokers, led by Father P. The Four P movement was actively involved in satanism, sacrifice, and murder. They have a subchapter called the “Black Cross” whose whole purpose is murder. Affiliated with Ordo Templi Orientis O.T.O. (The Zodiac symbol cirle with cross is combination of OTO and a black cross). All O.T.O. member positions are called degrees (I-XII).
    – Lastly, if you are good at Steganography, take a look at the Pen Postcard. The one that says “I would have written sooner, but I just washed my Pen”. There is a lot of obfuscated info there. The pen was drawn over, scribbled over, but you can still pull some info from it. Like “I’ll Kill, Slayers, Emeritus, part of a bomb diagram, for a train railroad maybe?). Check it yourself if you don’t believe me. Zodiac wasn’t a fool, all of the misspellings were done on purpose. They used the false Harden Decipherment to their advantage, but seemed to get tired of it later. “Slaves & Paradice” is funny if you think about it. Paradice = Pair (two), two dice are called “die”. So “two die”, just like their M.O. There are a lot of people that work on this in their spare time. If they begin to think in more astrological terms they might get somewhere. First forget about the Harden Homophonic Substitution crap, because it won’t get you anywhere.
    Take Care,
    Matt Brubach

  16. Matt: in recent years, the Hardens’ decryption has been independently verified by a number of different state-of-the-art homophonic cryptogram solving programmes – these solve homophonic cryptograms without any prior knowledge of the letter assignments. As a result, your suggestion that the Hardens got it wrong – regardless of the specific intuitive / guesswork-based steps they took to get to that same end-line – does not now seem supportable.

  17. Davey B on July 19, 2016 at 4:07 pm said:

    this looks interesting


  18. nickpelling on July 19, 2016 at 8:12 pm said:

    Davey B: looks like what I would call an “unintentional scam”. The Zodiac Killer ciphers are not connected; most will never likely be solved unless the author confesses all, perhaps in a letter or diary; some may very likely be fakes or hoaxes.

    Hence the probability that a single person has solved them all simultaneously without a super-sized portion of kid-yourself fries is basically zero, sorry.

    As always, I’d be delighted to be proved wrong, but I don’t seriously expect that to happen here. 🙁

  19. bdid1dr on July 19, 2016 at 10:38 pm said:

    Nick & friends: The Z killer is, himself, now dead. His daughter went to the morgue in New York City (about two or three years ago) and produced documents and photographs to confirm the dead man’s identity. He is buried near his last home in Marin County. No, I have none of those documents ,to ‘back up’ my side of the story — much less my sister-in-law’s story and her daughter’s story.

    All of the so-called translations/decipherments/guessworks/puzzle answers are now buried with the Zodiac’s remains. I’m hoping you will, sooner than later, discontinue attempts to solve the ravings of a seriously damaged once-brilliant mind.

    Speaking on the behalf of the dead man’s wife and child, and grand children.
    I remain respectfully interested in a whole lot of your other unsolved mysteries.

    beady-eyed wonder-r

  20. bdid1dr on July 19, 2016 at 10:43 pm said:

    BTW: The Z-Killer’s father outlived all of his children and grandchildren.

  21. bdid1dr on July 19, 2016 at 10:46 pm said:

    Correction: ‘outlived’ his children.

  22. Rick A. Roberts on July 22, 2016 at 1:44 am said:

    Has anyone looked at the ” Sandy Betts, Donna Lass ” internet site? She has a lot of information and insight into the identity of, ” The Zodiac Killer(s) “.

  23. John sanders on July 24, 2016 at 2:58 pm said:

    Photofit sure looks a lot like Rafael Cruze and I wonder whether Donald Trump has made suggestions to this effect. Just started to look this over for the first time in many years and if one cuts out all the hyper of which there is an overabundance the case does not seem over complicated (he chuckled).
    The crossed circle appears familiar and I believe it could have oriental origins but I’m sure things like this will come up when I get into it. First we must get more of the local stuff done and dusted I.e. Tamam Shud, Bogle-Chandler & the good old Gatton murders. Nothing like a dyed in the wool fair Dinkum thriller to get the blood up eh.

  24. Mr.Betyko on July 25, 2016 at 2:52 pm said:

    @Rick A. Roberts is this tell you something or nah!

    When ? the letter after not sure
    (N or A) or both*

    SASAESIH(?)LOD(?)RD(?)M(N or A)D

    So it could be:




    Or sometime like that

    This is the letter from ted all the word that are underlign first letter

  25. The message to the Zodiac, as shown on http://zodiacciphersresolved.com/, is taken from the San Francisco Examiner, Oct. 23, 1969, and reads:


  26. Davey b on August 11, 2016 at 2:39 pm said:

    Sooo….. the 18 symbol remainder @ the bottom of the 408 is not a Z cipher ?
    as it is not listed above as a authentic Zodiac cipher
    or you are guessing it is not ?

    Why are we sure the 408 is correct ? oh because it speaks in entire sentences and makes sense to what zodiac would say and the code key of it sort of makes sense ?

  27. nickpelling on August 11, 2016 at 3:22 pm said:

    Davey b: I’m just guessing. But I give my reasons for that guess, feel free to make your own guesses etc, I’m not stopping anyone doing anything. 🙂

    As far as the Z408 decryption goes, it is as correct as anyone can make it. There may ~possibly~ be alternative decryptions (i.e. plaintexts fitting the same homophonic ciphertext constraints): but given that cipher-breaking programmes with best-in-class homophone decryption algorithms find the same text that the Hardins did, the chances that any other decryption is equally satisfactory is dwindlingly small – by which I mean less than 1 in a million.

  28. Davey b on August 24, 2016 at 2:58 pm said:

    Hmmm… nickpelling
    Do you have access to these best in class cipher breaking homophone decryption algorithm programs ? and are ther polyphone programs ?

  29. I see you are here Nickpelling

    yes it’s my site ….. how about you running it thru the algorithm computer program ?

    anywaay you or someone like you , really need to see it … it is not like any others out there or I wouldn’t be asking that for it . It is a bomb shell …. let me know I will send it

  30. Cat Darensbourg on September 19, 2016 at 5:18 am said:

    Has anyone considered that there might be a pun in the name “Zodiac Killer” in the sense of *several* people in a ring going after victims in a particular order of the Zodiac? I know this must have been stated elsewhere, but what if we have more than one killer (more like a “Hunt Club” or “Surviving the Game” group of bored, dis-enfranchised specialists allowed to cause mischief as long as they did their government’s bidding at the end of the day, that would keep in form for more nefarious activities overseas by regularly evading the state-of-the-art police techniques at home as a matter of professional pride? One would have to be state level, one federal to coordinate and organize, and one in the media, to plant bogus clues. After that, you would only have room for at *most* six more — operating and coordinating across the map. This would mean a body count in the hundreds over the decades, and that the group was still open and operating today with promotion-from-within by deadman’s-shoes. Mess up, and the group turns and pirannah’s the erring member from within. An elite, organized, *never* for hire band of varying members that were — at one point — tighter than the freemasons who would have nothing to do with them for mutual disgust between the two groups. Not fear from either side — just dynamic disgust with each other’s tactics. No green berets, nothing romantic like that which would leave a paper trail — just men on the Vietnam Wall or other memorials already assumed among the dead. Nothing to say they were ever trouble with their superiors, or of a particular religious or non-religious belief. Just . . . seriously wrong in the head. Not even tormented about it like bad slasher-flicks would have you believe. With about 2k quiet, personal kills each before they would be able to even sniff at the possibility of being an official group member. No pins, no logos, no nothing.

    Just out there, doing their job for the corrupt arm of a military branch that needs a hit without presidential permission or oversight now-and-then.

    And nodding at other organizations in other countries that do the same . . .

    Speculating at this point.

    For now . . .

  31. Lits von Lats on December 29, 2016 at 5:12 pm said:

    D.(G).V.V. aka Cb, Glendale.

  32. Rick A. Roberts on May 16, 2017 at 4:21 am said:

    Cat Darensbourg and all,
    I reread your posting of 19SEPT16 and I think that your idea of the killings being done in a ” Sign of the Zodiac ” order is very interesting. I, too think that there is a group of four people who are responsible. The “My Name Is …” Cipher seems to have multiple solutions that have led me to this thought.

  33. Wolfmother on May 24, 2017 at 9:01 pm said:

    Could you post photos of the other unsolved zodiac codes? Thanks! I’ve been practicing with them for a healthy puzzle to ponder.

  34. Brian Cameron on June 22, 2017 at 10:06 pm said:

    I have wondered if certain symbols like ‘+’ or ‘-‘ might be used to interrupt patterns in different ways, perhaps indicating that the method of transposition is changing through the cipher.

    For example, if you broke up the cipher into blocks of text between these two characters, sections that precede a ‘+’ symbol could be read left-to-right and sections that precede a ‘-‘ symbol could be read right-to-left.

    The Alberti Cipher from 1466 is an example of a cipher that uses certain letters (capitalized ones) to indicate a change in the encryption algorithm. The Alberti cipher uses such special characters to change the key rather than the transposition system, but is an example of a cipher with a similar approach as what I am suggesting.

    My above suggestion does not account for the places where you see symbols like ‘+’ and ‘-‘ immediately repeat or follow each other, though these could indicate a more complex system of transposition being used. Though, these double symbols could just as easily be a null or indicate the end of a sentence.

    I also wonder if the ‘+’ and ‘-‘ symbols could mean something like “the preceding character plus 1 or minus 1, so considering the symbols “O++”,

    if O decrypts to D, then you get “DEF” found in words like “definite” or word combinations like “made (any word starting with F)”.
    If O decrypts to “N” this would decrypt to “NOP” found in words like “unopened” or word combinations like “no (any word starting with P)”.
    If O decrypts to “H” this would decrypt to “HIJ” like in “hijack”.

    If you wanted to use a technique like this, you could probably make an effort to make use of such words/word combinations to make it appear more often than you would find in natural text.

    Obviously there are a lot of other ways you could use this kind of technique. For example, since vowels are very commonly used letters, perhaps these special ‘+’ and ‘-” characters only affect the substitution of vowels. So a + symbol might mean that characters that translated to “A” before the ‘+’ symbol translate to the next vowel ‘E’ after the ‘+’. After a double ‘+’, the ‘A’ would translate to an ‘I’.

    I also think it is interesting that many people seem to think that the fact that you can almost read “ZODAIK” in the last line that this is probably filler. The choice of some letter substations may have been made to specifically create certain desired patterns. In other words, the fact that the cipher contains some interesting symmetry of symbols could just as easily be designed by some combination of particular word/sentence choice, misspellings, symbol choice, etc.

    Above I am assuming that the ‘+’ and ‘-‘ characters are the only characters that are special in this way. I am just using this to explain the concept. Obviously, there might just be a single symbol or more than 2 symbols that affect the algorithm instead of being characters to decrypt.

  35. Brian Cameron: you may disagree, but for me the problem with complicated Zodiac super-systems (one might even call them “meta-systems”) is that there’s no real evidence that the Zodiac Killer was cerebral in that kind of way. There’s something a bit jarring about +, for sure: but it’s a long javelin throw from there to “HIJ(ACK)” etc, and so our time is probably better investing looking at the other letter shapes (of which there are many) and wondering just what is going on with the cipher at a very high level.

    As I recall, Alberti’s book merely says that the encipherer and decipherer should agree between themselves how often to shunt the rotor round: whether it’s every 5 characters or 3 words is up to them.

  36. Brian Cameron on July 12, 2017 at 7:40 am said:

    Thanks Nick for the comments. The Alberti cipher was the first polyalphabetic cipher and was developed in 1466. It was a precursor to the Vigenère cipher in 1585. There are a lot of websites that confuse the Alberti cipher, but if you read the Wikipedia page for the Alberti Cipher it quotes him directly and you can see how only lower case letters are encoded and upper case characters were the trigger to shift the cipher key. The Belaso cipher in 1553 was the first polyalphabetic cipher to change the key with each character.

    Claude Shannon in 1949 defined the Product cipher which was the first cipher to combine substitution and transposition ciphers in a complex way. So someone in the late 1960’s who was familiar with ciphers could easily consider their own approach without developing a complex “super” system. The fact that the Zodiac is known to have picked a Homophonic cipher system, a system that was last popular in the Middle Ages, could indicate the Zodiac did do some cipher research. Shifting the key once for every + symbol would require some innovation but is not a particularly mind-blowing leap.

    I have not spent any time analyzing the cipher to test this approach. I just thought it would be interesting to share some of my thoughts comparing the Zodiac and Alberti ciphers and considering how special characters could modify the encryption algorithm.

    I am not saying this The approach the Zodiac used, but a cipher using this technique could create ciphertext where a single character or handful of characters repeats frequently.

Leave a Reply

Your email address will not be published. Required fields are marked *