Using old and new material, we will take a comprehensive look at the 'Dripping Pen' card mailed by the Zodiac Killer on November 8th 1969, and attempt to link it to a future threat of murder. The card itself was most likely chosen for purpose, referencing the immediate aftermath of the attack on Bryan Hartnell and Cecelia Shepard at Lake Berryessa on September 27th 1969. Approximately five minutes after the brutal stabbing, the killer walked to the side of Bryan Hartnell's white Volkswagen Karmann Ghia and wrote "Vallejo 12-20-68, 7-4-69, Sept 27-69 -6:30 by knife". The hand the killer wrote on the car door with, was likely the hand he used during the attack on the young couple, almost certainly peppering his dominant hand with blood, and consequently to the marker pen he wrote with. So, the choice of greeting card stating "Sorry I haven't written, but I just washed my pen" was likely a sardonic reference to the callous and bloody attack at Lake Berryessa. The addition of "Aug" on the card inner, a suggestion of his involvement in the double murder of Deborah Furlong and Kathy Snoozy in San Jose on August 3rd 1969. This, coupled with the footnote of "by knife" written on the car door, was likely deliberately engineered to steer investigators toward this conclusion. They had after all considered this premise in the October 1st 1969 edition of the San Francisco Examiner, in which was stated "And today San Jose police, to the south, inquired of law enforcement officers here whether there was indication that the "Cipher Killer" might be linked to the knife slaying of two teenage girls Aug.3, still unsolved". This wouldn't be forgotten by the Zodiac Killer.   

Another reason to believe the 'Dripping Pen' card was referring to Lake Berryessa can be found in its design. The Zodiac Killer, almost without exception, would give us a running total of his victims, occasionally writing the victim count on the horizontal wing of the crosshairs. The only two times this was not the case, was the November 8th 1969 'Dripping Pen' card and the car door of Bryan Hartnell's white Volkswagen Karmann Ghia. In both of these writings he gave us his Zodiac crosshairs with the months of his murders underneath. This was the first and last time he would ever do this.

If you run the message from the face of the 'Dripping Pen' card to inner, it reads "Sorry I haven't written, but I just washed my pen and I can't do a thing with it". So, when the Zodiac Killer wrote "I get aufully lonely when I am ignored, so lonely I could do my Thing", he was indicating that in the future when he needed some attention, he would write again. His Thing being his propensity to put pen to paper, or in the case of Lake Berryessa, to metal. He was effectively addressing the police when he wrote "I though you would need a good laugh before you hear the bad news. You won't get the news for a while yet". In fact, the bad news would arrive in exactly thirteen days time - and it was directed towards the police in regards to the month of August. In effect, his next correspondence would be pushing the same narrative as the car door and greetings card, of his involvement in the deaths of Deborah Furlong and Kathy Snoozy. 

​On November 21st 1969, a letter arrived at the San Jose Police Department, addressed to a particular law enforcement officer. The letter was threatening a widow - so much so - that police initiated 24-hour surveillance on the woman's home. The police stated that "they believed the widow in the message may be Mrs......" In other words, the woman wasn't directly named in the correspondence, but they had by reasonable deduction, concluded who the threat was aimed at. I believe that the Zodiac Killer, in his continued drive to cement the notion of his involvement in the two teenage girls murders, mailed this "bad news" to the San Jose Police Department. Can it really be a coincidence that he wrote "by knife" on the car door to plant the seed, added the "Aug" on the 'Dripping Pen' card, then mailed his next correspondence to the City of San Jose? In addition, this new communication began with some familiar words: "There's no doubt I will do my Thing".  

On November 21st 1969, the San Jose Police Department would still have been devoting many hours to the unsolved murders of these two teenage girls, and likely receiving many tips from potential eyewitnesses and the residents of San Jose, eager to assist in the investigation. What better way for the Zodiac Killer to convince law enforcement of his potential involvement in this crime, by threatening to do his Thing on one of these residents.

I have no doubt the Zodiac Killer was scouring the newspapers about this crime - so imagine he came across such a headline:
"An elderly widow, Maureen Jones, was today helping police with their investigation into the senseless murders of two young girls in San Jose, Sergeant Johnston said", or "An elderly widow, residing at Seacreek Way, was today helping police with their investigation into the senseless murders of two young girls in San Jose, Sergeant Johnston said". These article excerpts are fictitious, designed to show what Zodiac  may have read in any number of articles I have no access to. 

The Zodiac Killer never mentioned his victims by name, so it is entirely plausible that whether he knew this woman's name or not, he could, by sending a threatening letter to police using the term "widow", and addressing the communication to "Sergeant Johnston", convince police that the threat was a credible one. This may be why the police believed they knew who the woman was, despite the fact her name was never mentioned in the correspondence mailed to the San Jose Police Department. Because she had recently received newspaper coverage.     

A small code arrived with the November 21st 1969 communication. The short code (shown above in the FBI files) was
​-- + 6 2 + --, containing two dashes either side, two pluses, and the numbers 6 and 2. The idea that anybody looking at this code could arrive at 1620, without having previous reason to suspect this four number solution, seems unlikely. But if investigators knew that "Maureen Jones" lived at a residence, such as 1620 Seacreek Way, San Jose, then they might have reason to believe this is what the code was implying. Earlier newspaper reports stated "A killer armed with a thin-bladed stiletto was hunted here today as the one who savagely stabbed to death two teenage girls yesterday as they picknicked in Almaden Valley. The scene where the bodies were found is just south of Blossom Hill Road, two blocks west of Calahan in the northern end of the valley. About 10:00 am yesterday, the girls packed a lunch and left Deborah's parents' San Jose home for a picnic atop a grassy knoll nearby. The picnic ground is a rugged area, near a narrow, serpentine trail used by motorcyclists for hill-climbing contests".  So, if we could find a 1620 residence in San Jose, possibly close to the crime scene, this may be the location of the "widow" Zodiac was targeting.

As shown above, in the October 1st 1969 San Francisco Examiner article, "San Jose police, to the south, inquired of law enforcement officers here whether there was indication that the "Cipher Killer" might be linked to the knife slaying of two teenage girls Aug.3".  Therefore, would it really be that surprising if the Zodiac Killer had capitalized on their suspicions and mailed a threat to the San Jose Police Department? He knew he would be taken seriously by police - and why they were prepared to instigate 24-hour surveillance on the residence of the "widow" mentioned in the letter.

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.