The Zodiac Killer on August 6th 1969, after viewing the extensive front page coverage of this crime that he believed he deserved, very likely switched to a knife for his brutal attack on Bryan Hartnell and Cecelia Shepard at Lake Berryessa on September 27th 1969. The Zodiac Killer would indirectly refer to Kathy Snoozy and Deborah Furlong through multiple communications spanning two years, most notably the "by knife" attribution on Bryan Hartnell's car door and the Dripping Pen card, when he inflated his victim total to seven by adding the month of "Aug". He may also have done this in the December 16th 1969 Fairfield letter when he drew the Bleeding Knife of Zodiac with seven drops of blood falling from the blade. He wasn't responsible for the murders of Kathy Snoozy and Deborah Furlong on August 3rd 1969, but he wanted us to believe he was.
This leads us to the Halloween card on October 27th 1970, approximately one year after the Dripping Pen card. The greeting card contained an eye peeking from the knothole of a tree with the circled wording of "peek-a-boo you are doomed". It is this childlike terminology of "peek-a-boo" used by parents when playing with their children, that could reveal an alternative meaning to the Halloween card. There are many variations of "peek-a-boo", such as where trees are involved: "Hiding behind that tree" is sometimes added. Wikipedia. Kathy Snoozy (15) and Deborah Furlong (14) were extremely young victims, with Kathy Snoozy described by investigators as much younger looking than 15 years. The Halloween card depicting a tree with somebody hiding behind it, in accompaniment to the two skeletons adorning the card (one purposefully added}, seemed to mirror the attack on the two young girls by an oak tree. The Halloween card deliberately designed to signify two victims, explaining why the Zodiac Killer went to the extra effort of adding a second skeleton to the card inner, and featuring "by knife" on the rear of the card, just like he did on the car door of Bryan Hartnell at Lake Berryessa.
The Zodiac got creative by listing seven victims with the addition of "Aug" on November 8th 1969 and adding seven drops of blood on December 16th 1969 on the Bleeding Knife of Zodiac drawing, so did he get creative in the Halloween card? The Zodiac Killer didn't write 4-TEEN as his victim total for no reason, therefore we have to examine why he did it. The number 4 is self evident, meaning 4 victims. The word TEEN is short for teenager or teenagers. This indicates that the Zodiac Killer has incorporated 4 teenagers into his victim total of fourteen. At this juncture, he was claiming the murders of Betty Lou Jensen (16), David Faraday (17), Darlene Ferrin (22), Cecelia Shepard (22), Kathy Snoozy (15), Deborah Furlong (14), Paul Stine (29), Richard Radetich (25) and Donna Lass (25). That is nine claimed victims of the fourteen he had placed on the Halloween card, but only four were teenagers, hence the wording of 4-TEEN. The two skeletons may sadly have represented Snoozy and Furlong, adding the two teenagers from San Jose to the existing two teenagers from Lake Herman Road in Benicia, that we already knew for certain.
Halloween is a time when the children venture out into the night, dressed in costumes to play trick or treat in the neighborhood. The Zodiac Killer, on the other hand, may have played the sickest game of all, when he mailed the Halloween card on October 27th 1970, claiming yet again his involvement in two murders he had no hand in.