Thirteen days after the Zodiac Killer mailed the 'Dripping Pen' card and 340 cipher on November 8th 1969, another letter and code purporting to be from the Bay Area murderer was mailed to the San Jose Police Department on November 21st 1969, possibly containing a threat on a "widow" in the San Jose area. Both mailings have so much in common, along with the December 7th and 16th 1969 Fairfield letters, which also contained rudimentary codes. The Zodiac Killer wrote the chronological months of his murders at the foot of the 'Dripping Pen' card: "Des, July, Aug, Sept, Oct = 7". Bearing in mind that all but August were accounted for, it is now clear the card was inferring the murders of two young girls, Deborah Gaye Furlong (14) and Kathy Ann Snoozy (15), who were found savagely stabbed on August 3rd 1969 in the Bay Area of San Jose. It is therefore no surprise that his next communication should be focused on San Jose just two weeks later. Below is part of the FBI file revealing some of its contents.

Placing "November=8" could be viewed as an extension to his "Des, July, Aug, Sept, Oct = 7", indicating he was claiming another murder in November. He also began the communication with familiar words: "There's no doubt I will do my Thing". As the communication was mailed to the San Jose Police Department, we would now have three victims in San Jose to which he was laying claim to. The short code (shown above) was -- + 6 2 + --, containing two dashes either side, two pluses, and the numbers 6 and 2. Both Fairfield letters contained rudimentary codes pertaining to the 340 cipher, as though he was giving us a clue to its design. This may also have been the case when he mailed the Halloween card on October 27th 1970, intersecting the words Paradice and Slaves in a cross formation and writing "sorry no cipher" in similar fashion on the envelope. In fact, the December 16th 1969 Fairfield letter contained a design similar to the Halloween card. The 340 cipher can be shown to accommodate the words Paradice and Slaves, bisecting the cipher horizontally and vertically across its mid-section. This opened up the possibility that the San Jose code was somehow connected to this design. Both Fairfield letters harked back to the 340 cipher, so why not the San Jose code also.  

The symbols contained in the San Jose code exactly mirror the order shown on the horizontal mid-section of the 340 cipher. The 10th line is where some believe the cipher could be divided, along with the possibility of the word Slaves residing. Not only do the dashes and pluses line up exactly with the San Jose code using the mid-section of the 340 cipher, but the numbers 6 and 2 would slot nicely in between. If we used basic number play, and converted 6 to F and 2 to B, both these letters can be found together on the 10th line also. All six characters from the San Jose code present on the Slaves line of the 340 cipher. 

This may very well be coincidence, but with "There's no doubt I will do my Thing", "November=8" and this correspondence immediately following the 'Dripping Pen' card and 340 cipher, one could argue the Zodiac Killer was dropping us hints to the mechanics of his "crackproof" cipher. Something he would again do with the arrival of both Fairfield letters in December.

The Zodiac Killer could wait only one month after the Button letter, to give us further clues regarding the bomb he claimed to have buried, when he wrote "P.S. The Mt. Diablo code concerns Radians + # inches along the radians". Why should the San Jose and Fairfield letters be any different?   

With extensive work done by AK Wilks on this topic, I would like to take a further look at the letter and code mailed to the San Jose Police Department on November 21st 1969. This came just ten days before the abduction of Elaine Davis from Walnut Creek on December 1st 1969. Her abductor traveling from the Bay Area, depositing her Navy peacoat just 26 miles south of San Jose, likely passing through it on his way to Light House Point in Santa Cruz. If the Zodiac was responsible for both letter and murder, then San Jose is a worthy avenue of interest. AK Wilks asked a pertinent question of the forum: "Does someone know of a recent murder case in San Jose that left someone a widow? Or a prominent widow who lived in San Jose in 1969? The police were seemingly able to determine who it was, so perhaps it was a well known case or person". The brief text in the letter clearly contained enough information for police to identify the woman and implement 24 hour surveillance on her residence. Was the author threatening to kill the 'widow' or abduct her from her residence?

The Zodiac Killer (or copycat) mailed a menacing postcard to Dr, Edward Adams in Orinda, California (near Walnut Creek) on October 12th 1970 stating "The Zodiac is going to change the way of committing murders. I shall announce when I shall commit my murders, The Adamses are Next you taught me to Mean it. ADAMS YOU ARE NEXT. ZODIAC."
As shown on the ZodiacKillerSite forum, Dr. Edward Adams and his wife featured in the newspapers prior to this threatening communication, so it is perfectly feasible that the author of the San Jose letter and code had identified his target in the days, weeks or months prior to the November 21st 1969 correspondence. Because of the nature of the redacted text, it appears that this letter was addressed specifically to a titled officer (possibly a Sergeant or Chief) of the San Jose Police Department. Bearing in mind the target of a 'widow' mentioned in the text, the author may be referring to a newspaper article involving the death of her husband, featuring commentary by the police official the letter is addressed to. The officer's name could be any number of characters in length depending on the title he holds, with the widow's surname just 5 or 6 characters in length. 
Was the widow a prominent member of society as suggested by AK Wilks, possibly a policewoman or politician, titled like Dr. Edward Adams. The Zodiac, on December 16th 1969, had set his sights on a cop or "government life". 

On the left is a December 22nd 1969 newspaper report from the San Mateo Times of somebody identifying himself as 'Zodiac' and threatening to kill five patrolmen and a family of five over the weekend, not dissimilar to his written threats in his trinity of July 31st 1969 letters: "I will cruse around all weekend killing lone people in the night then move on to kill again, until I end up with a dozen people over the weekend". 
The phone call was received on Friday December 19th 1969 by San Jose police dispatcher Shirley Searcy.

The disputed December 7th and 16th 1969 Fairfield letters (not published in the newspapers) both contained threats to murder cops for the first time, with the latter threatening to murder one policeman in San Jose. Three days later, this call to a San Jose Highway Patrol station threatening to murder police is remarkable timing. Was the caller responsible for both Fairfield letters - and more importantly - was it the Zodiac Killer?

I have searched high and low for the identity of this woman, but without a newspapers.com account to aid in the search, I have failed to make any inroads. The author of the San Jose letter (if Zodiac) certainly didn't need a valid reason to target anybody, as shown by his murderous assault in the Bay Area, but the identity of the 'widow' could help to add legitimacy to both Fairfield letters mailed in December, dependent on her profession or previous relationship. The November 21st, December 7th and December 16th communications all contained short codes, the amateurish nature of which, has led many to believe these three letters are the work of an impostor. But these features may actually bolster the argument for Zodiac involvement, as all three were never attempting to mimic the previously polished 408 and 340 cipher, which somebody attempting to mimic the Zodiac would surely have done.  

On November 21st 1969 a suspected Zodiac letter was received.
The FBI file read: 'Re Butte tel to Bureau 11/21/69.
Enclosed herewith for the FBI laboratory are two copies of the letter received by (redacted) San Jose PD, San Jose, California on this date.
As noted, the message reads (redacted). 
The laboratory is requested to have the Cryptogram Section attempt to immediately decipher the message and furnish the results to the San Francisco Office.
For the information of the Bureau and Sacramento, after a cursory analysis, officers of the San Jose, California PD, believe widow in message may be Mrs (redacted), San Jose, California. San Jose PD instituting 24 hour surveillance on Mrs (redacted).'
A further page read:
11/24/69 - 'Copy of handprinted note beginning "There's no doubt I will do my Thing!" and ending with the symbol (drawn crosshairs). Results of examination:
The ciphertext portion of Qc33 is not readable using previously recovered key. Its brevity precludes further cryptanalytic examination at this time. The furnished interpretation of  "- + 62 + -" as representing "1620" can be neither proved nor disproved analytically. The = between "November" and "8" could represent the number "2". Such interpretation would be based on inferences drawn from the date of the postmark, not from cryptanalytic examination.'  (see below for FBI files).​ 

The FBI files ponder the idea of "November" and "8" being bridged by the number 2, possibly giving us November 28th, and therefore tying in with a presumed threat on a widow from San Jose. Here are some thoughts on Zodiac Killer Site forum. 
However, there may be a much simpler explanation, bearing in mind the Zodiac Killer's last two communications on November 8th and 9th of 1969- in particular the 'Dripping Pen' card.

That "November = 8" means exactly what it states- that the author or Zodiac is threatening, or has already claimed victim number 8 sometime in November.
​Bearing in mind the 'Bus Bomb' letter mailed on November 9th 1969 claiming 7 kills, then had an 8th victim already been claimed (presumably a male victim, if the mention of a widow was relevant), we would be looking for a victim between November 9th and November 21st. A future victim in November would likely have been murdered between November 21st and November 30th (the claimed target possibly being the woman in San Jose).
The phrase "There's no doubt I will do my Thing!" seemed to suggest an impending threat- hence the urgency of 24 hour surveillance on the woman. Thereby, the use of the term "widow" in the FBI file may likely not carry a sinister connotation of a prior murder.  
The Zodiac Killer was certainly looking for a ninth and tenth victim on December 20th 1969, when he mailed a further correspondence to Melvin Belli's residence.
​The reference to "- + 62 + -" appears to represent six characters rather than four, so is open to interpretation. 
Here is an aerial view of 2162 Ringwood Avenue, San Jose, Ca.  A code such as 2162SJ, coupled with a specific name would be enough. This is just a crude example, so any suggestions would be welcome.