The one thing we know about the Zodiac Killer was his eagerness to follow the newspaper coverage about his crimes and communications, often responding directly in subsequent letters to the San Francisco Chronicle. Being a narcissist, there is every chance the Zodiac Killer kept news cuttings of his escapades, just like many narcissistic trends on social media today. This may explain why he was able to respond to law enforcement quotes in the newspapers after eight years had passed (unless the following is a coincidence). One such example was the 1986 'Freeway' letter mailed to the San Francisco Chronicle on May 6th 1986. This letter began, "This is the Zodiac speaking. I am still out here and crack proof". This is what Inspector David Toschi stated in the San Francisco Chronicle on April 26th 1978 after the arrival of the latest Zodiac letter. Was the introduction in the 1986 letter a response to Inspector David Toschi after an eight year hiatus?
The letter and envelope of the 1978 letter was examined by law enforcement. Here is what was written in the San Francisco Chronicle on April 28th 1978: "Toschi said yesterday that the common, while envelope had no outstanding marks and that the single piece of plain white stationary on which the note was written contained nothing that would give us any indication where he might have gotten it. It was also learned that although the envelope bore a San Francisco postmark, other notations on the cancelation indicated that the letter might have been mailed in San Mateo county or Santa Clara county and was brought here for processing". Law enforcement, at the time, considered this the first contact from the Zodiac Killer since he last wrote the Exorcist letter in January, 1974. If this analysis by law enforcement is correct, then the individual who mailed the 1978 letter, mailed it from the same location as the Exorcist letter, separated by just over four years. They say old habits die hard.