Without knowledge of these 'dubious' letters existence or having seen them in any newspapers, it would be uncanny how the Zodiac Killer would continue the theme of these two letters into the 'Melvin Belli' letter on December 20th 1969, the 'My Name is.' letter on April 20th 1970 and the 'Button' letter mailed on June 26th 1970. In other words, three of his next four communications. Here is the theme running consecutively, starting with the December 7th 1969 letter:
"I just need help. I will kill again so expect it any time now. The will be a cop. Then I will turn myself in OK. I will kill in SF 3 times (including cops). The one thing I ask of you is this, please help me. Please help me I cannot remain in control for much longer. But there is more glory in killing a cop than a cid because a cop can shoot back. I shot a man sitting in a parked car with a .38".
It is clear from the December 7th and 16th communications the author is threatening 'government life'- most likely the police. In the December 7th 1969 communication the author has supplied a code containing 38 characters, followed by the December 16th 1969 letter threatening another 38 kills including cops, and curiously in his June 26th 1970 'Button' letter, the claim of shooting "a man with a .38." Most likely coincidence, but you never know. Here is a forum thread on Zodiac Killer Site with some of the same salient observations, particularly by AK Wilks. The 38 character December 7th 1969 Fairfield letter (below) has been cleaned up and darkened to make the letter more readable.
"I just need help. I will kill again so expect it any time now. The will be a cop. Then I will Turn myself in OK".
A hoaxer could easily have copied elements of the 340 cipher and incorporated them into what many believe is a poor imitation of a Zodiac correspondence. But if the Zodiac Killer hadn't seen either of the two Fairfield letters, do we attribute the continuing theme through three of the next four genuine Zodiac correspondences as just sheer luck, referring to "needing help" and his suggestion of "killing a cop." Additionally, from the 'double event' November 8th/9th 1969 contact, we have effectively been given four ciphers or codes (whether crude or not) in five correspondences. These observations may lend more credence to the Fairfield communications and their rightful place as having been penned by the hand of the Zodiac Killer.
THE MESSAGE WITHIN THE FAIRFIELD LETTER