
In the San Jose Mercury on August 6th 1969, Dr. John Hauser, who performed the two autopsies on the teenage girls, stated that he couldn't attribute a specific cause of death, but concluded that it may have been from "bleeding" or lacerations of internal organs or both. On the same day, August 6th 1969, the Los Angeles Herald & Examiner ran an article entitled "The Victims: 16 Young Girls", featuring pictures of Kathie Snoozy and Debra Furlong. The picture of Debra Furlong had the wording "killed by knife" written under it. The phrase "by knife" that was written on the car door at Lake Berryessa on September 27th 1969. One year later, on October 27th 1970, "by knife" was added to the Halloween card, which appeared to incorporate "4-TEEN" or "4 teenagers" into the running victim total of fourteen. The Zodiac Killer was only claiming the murders of four teenagers by October 27th 1970. They were David Faraday (17), Betty Lou Jensen (16), Kathie Snoozy (15) and Debra Furlong (14).

It appeared as though August 6th 1969 was integral to at least three "communications" (car door, Fairfield letter, Monticello card), and one phone call to the San Jose Highway Patrol on December 19th 1969, in which the Zodiac Killer spoke to dispatcher Shirley Searey and claimed he would "kill five of you officers and a family of five between now and Monday".
In 1971, two communications were mailed to the San Francisco Chronicle (the 148 character cipher in probably May and Monticello card on July 13th), which both indirectly referenced the Snoozy & Furlong murders and the recent murder of Kathy Bilek (18) in Saratoga on April 11th 1971. The 148 character cryptogram contained the ciphertext symbol of a "mirrored N", just like the Halloween card on October 27th 1970.. The phrase "by knife" was written on the Halloween card, not only reminiscent of the car door and picture of Debra Furlong, but the Halloween card very possibly also referenced Debra Furlong amongst the four teenagers he was claiming as victims at this juncture. The "mirrored N" would therefore have appeared in two communications from the Zodiac Killer, both of which suggested his involvement in the murders of Kathie Snoozy & Debra Furlong. The plaintext character for the "mirrored N" in the decrypted 148 character cryptogram was "K" for "Knife".
Another message would appear on September 18th 1973:
WHAT INSPIRED THE TOMBSTONE WRITING?