In addition, March Air Force Base was situated only 12 miles from Riverside City College Library, so plenty of military personnel were in close proximity to this particular crime scene. The Zodiac would then likely relocate to Northern California sometime after the Bates letters were mailed on April 30th 1967.
Fast forward one year and eight months, and the confirmed Zodiac Killer attacks began at Lake Herman Road and Blue Rock Springs Park, just 10 miles and 9 miles respectively from the Mare Island Naval Complex.
The Zodiac Killer may well have worked at the San Francisco Naval Shipyard located at Hunters Point, only 10 miles from the murder at Presidio Heights. The Navy discontinued use of the yard in 1974, when it was leased for commercial ship repairs.
Did the Zodiac work at Hunters Point before he was stationed in Alameda County? On May 8th 1974, the only Zodiac letter mailed from Alameda County would arrive at the San Francisco Chronicle, followed by the 'Red Phantom' letter on July 8th 1974 from San Rafael.
[See below] An FBI report from a confidential source mentioned a 'look alike' for Zodiac, who had served either in the US Army or US Air Force between June 1966 and August 1970, allegedly stationed in the San Francisco Bay Area and Riverside, California. This document also details the abduction of Kathleen Johns on March 22nd 1970 on Highway 132, west of Modesto and finishes by stating the 'subject' in question was reportedly stationed in Patterson at the time. Kathleen Johns described the man who abducted her that night, as possibly having a military connection, describing him as a "WMA, 160 lbs, approx 30 years, 5'9" in height, dark hair and clean-cut, rimmed plastic glasses, having the traits of a serviceman."
This crime has often divided the Zodiac community. If the Zodiac Killer lived in the Bay Area, it seems strange that he would drive a 180 mile round trip just to commit an abduction in the middle of nowhere. There is such as thing as a buffer zone employed by criminals, but 90 miles traveling distance, fast approaching midnight, appears unlikely - unless of course, he had an alternative reason to be there that night - he may have been returning home from visiting relatives, had been on a hunting or fishing trip, or any other form of recreation. It is unlikely he lived near Highway 132, as many communications would subsequently arrive during 1970, postmarked San Francisco. It is conceivable he made this journey daily, lived in two places, or had a profession that required mobility and flexibility. Was he returning to the Bay Area that night from an outpost connected to the military? This is the avenue we shall examine.
Kathleen Johns was abducted on Highway 132, just west of the I-5 and Vernalis Road crossover point, near Bird Road and the same place her vehicle was ultimately found burnt out by police. If the Zodiac Killer was traveling on Highway 132, where had he come from that night? He was in possession of a flashlight - so had he been working late in a military facility, that would bring him out onto Highway 132 just behind Kathleen Johns circa 11.45 pm.
Only 25 miles south of the area where Kathleen Johns was abducted is the Naval Auxiliary Air Station Crows Landing in Patterson. Following World War II, Crows Landing became an Outlying Land Field to the Naval Air Station in Alameda, and later Moffett Field, near the south end of San Francisco. So another connection exists.
As you exit NASA Crows Landing to return to the Bay Area, the quickest route is immediately onto Interstate 5, which then joins Highway 132 only 1.4 miles before the point where Kathleen Johns was flagged over and where her vehicle was eventually discovered burnt out. The Zodiac Killer would have entered Highway 132 just behind Kathleen Johns and trailed her for approximately 2 minutes, before he made his move.
One last noteworthy observation is in respect to the immediate correspondence after the Modesto abduction. The '13 Symbol' cipher was mailed on April 20th 1970, one month after this abduction. Here is the code the Zodiac mailed.
And here is the FBI file;