
Upset with law enforcement and Werner, who the Zodiac Killer probably viewed with disdain, needed to reclaim the victims and threaten further action in the coming days or weeks. The 148 character cipher and letter laid bare his intentions by threatening to "skin three little kids and make a suit from the skin", and mail "a patch of human skin if there is some left over". This was straight from the playbook of Theodore Edward Gein, who roamed the graveyards of Plainfield, Wisconsin looking to exhume body parts to fashion grisly souvenirs from the skin and bones. His mother, Augusta Wilhelmine Gein (who died on December 29th 1945), was a domineering woman with an intense hatred for females, but whose death from a stroke left Edward Gein devastated and alone in the farmhouse. Soon after his mother's death, Gein began to create a "woman suit" from pieces of skin so that "he could become his mother and literally crawl into her skin". It appeared as though Edward Gein wanted to feel close to his dead mother and become the embodiment of her once life.

When Norman was a teenager, his mother met Joe Considine and planned to marry, who then convinces Norma to open a motel. Norman grows furiously jealous, believing that Norma has abandoned him for her fiancé, and murders them both with strychnine. He then stages it like murder-suicide, making it look as if Norma had killed Considine and then herself. Unable to bear the loss of his mother, Norman stole Norma's corpse and mummified it in the fruit cellar, and spoke to it as if his mother were still alive. He also spoke to himself in her voice and frequently dressed in her clothes. Norman Bates has effectively become his mother in order to escape the awareness of her death and the guilt of having murdered her". Wikipedia.
It is plain to see the similarities between Norman Bates and Edward Gein, both of whom were controlled by a domineering mother with a hatred for other females, whose male fantasies centered on their mothers living on after death. The following newspaper clipping from the Chicago Daily News on November 20th 1957 describes a mother who often told Edward Gein and his brother to "Watch out for women. They are evil".

Kathy Bilek was buried in the Madronia Cemetery in Saratoga, Debra Furlong in the Oak Wood Cemetery in Santa Cruz, and Kathie Snoozy in the Oak Hill Memorial Park & Cemetery in the Monticello neighborhood of San Jose. The pasted phrase of "Near Monticello Shought Victims 21 ...... In The Woods Dies April" in the Zodiac Killer's Monticello card on July 13th 1971, was referencing the murder of Kathy Bilek on April 11th 1971 in the Villa Montalvo woods in Saratoga, not far from the Monticello neighborhood where Kathie Snoozy was buried. The Zodiac Killer was tying both victims together under the banner of one postcard - and by extension - the murder of Debra Furlong.
Any doubts that this was the case were expelled on September 18th 1973, when somebody removed a tombstone from the Oak Hill Memorial Park & Cemetery in the Monticello neighborhood of San Jose and placed it in front of the cemetery gate. The tombstone had the pseudonym "Zodiac" written on it in crayon. In the whole of California (and America) we have only one instance of a tombstone being removed from a cemetery with the pseudonym "Zodiac" being written on it - and it just happened to be from the Oak Hill Memorial Park & Cemetery in the Monticello neighborhood of San Jose where Kathie Snoozy was buried. It's pretty obvious this deed was done by the Zodiac Killer, especially when you consider that the contents of the Monticello card were not publicly known on September 18th 1973. This was a Zodiac Killer who threatened to dig up the bodies of the three girls, who later visited the gravesite of Kathie Snoozy. This connection should have been made in 1973.

I wondered whether the Zodiac Killer may have been responsible for this six-page letter, because we know of the Zodiac Killer's propensity to write multi-paged letters, often interjecting himself into murder investigations he had no involvement in. But it was something else in the January 19th 1978 letter that struck a chord. It reminded me of the movie "Psycho", based loosely on the story of Edward Theodore Gein. The letter told of a man who had killed his mother, who couldn't get her out of his head. A woman who told him to "kill those bad and evil ladys", just like the mother of Edward Gein, who told her sons to "Watch out for women. They are evil". The author of the January 19th 1978 letter claimed that his mother made his "head hurt", not unlike the character of Norman Bates in the movie "Psycho". We know that the Zodiac Killer referenced the movies and its award ceremonies throughout his communications, so did the film "Psycho" bridge the gap from 1971 to 1978 in the musings of one mind. Below is page one of the January 19th 1978 correspondence.
A FOUR YEAR JOURNEY TO TOMBSTONE