The Zodiac Killer after killing four people in Benicia, Vallejo and Napa, suddenly switched the emphasis to the heart of San Francisco, mailing a letter to the San Francisco Chronicle on October 13th 1969, promising to target a school bus and "pick of the kiddies as they come bouncing out". In the following months came multiple references to bombs, notably in his 'My Name is' letter, detailing a bus bomb diagram and suggesting he was not responsible for wiping out "that blue meannie with a bomb". He was describing the murder of San Francisco police officer Brian McDonnell on February 16th 1970, two months earlier, when a bomb packed with fence staples exploded on an outside ledge of Park Police Station in the Upper Haight neighborhood. The Zodiac Killer then mailed the Dragon card on April 28th 1970 stating "I hope you enjoy yourselves when I have my blast" and then the Button Letter on June 26th 1970, cementing his connection to San Francisco by part referencing the murder of a policeman in a parked car, thought to be Officer Richard Radetich outside 643 Waller Street. In this correspondence he attached a Phillips 66 road map of San Francisco and Vicinity, stating "the map coupled with this code will tell you where the bomb is set". Then on July 26th 1970 the 'Little List' letter was mailed, including two crosshairs, one with a prominent black circle including the acronym SFPD = 0 and the second referring us back to the Button letter, stating "The Mt Diablo code concerns radians + inches along the radians". The emphasis appeared squarely over the region of San Francisco, so was the bomb the Zodiac Killer promised us, to be found somewhere in this region.
What level of understanding the Zodiac Killer had regarding the concept of radians is unknown, but they are a counterclockwise value around the circumference of a circle. He placed his crosshairs over Mount Diablo, to which he added a sort of clock face, replacing the number twelve with a zero, stating it was "to be set to Mag.N". It can be shown that 4 radians and Magnetic North will fall within the bold, black circle he placed on his 'Little List' crosshairs. In addition, it can be shown that traveling 2 radians counterclockwise from True North will again fall within the bold, black circle. The use of the clock face and the directional north marker set at zero, may indicate that Zodiac intended this as his starting point for any calculations. The mere fact that the above measurements, either clockwise or counterclockwise, using whole radians, both fall inside the black circle, would seem to suggest that the 246 degree angle subtended from Mount Diablo over San Francisco is where we should be looking.
What level of understanding the Zodiac Killer had regarding the concept of radians is unknown, but they are a counterclockwise value around the circumference of a circle. He placed his crosshairs over Mount Diablo, to which he added a sort of clock face, replacing the number twelve with a zero, stating it was "to be set to Mag.N". It can be shown that 4 radians and Magnetic North will fall within the bold, black circle he placed on his 'Little List' crosshairs. In addition, it can be shown that traveling 2 radians counterclockwise from True North will again fall within the bold, black circle. The use of the clock face and the directional north marker set at zero, may indicate that Zodiac intended this as his starting point for any calculations. The mere fact that the above measurements, either clockwise or counterclockwise, using whole radians, both fall inside the black circle, would seem to suggest that the 246 degree angle subtended from Mount Diablo over San Francisco is where we should be looking.
The Zodiac Killer referred to radians (an angle of measurement), of which one radian is valued at 57.296 degrees. If we look at the prominent black circle he gave us on the 'Little List' letter (shown on the right), its center falls over the 246 degree mark on a compass rose. 246 degrees is 4 radians + 17 degrees. When the Phillips 66 road map was mailed on June 26th 1970, Magnetic North was approximately 17 degrees.
4 radians = 4 X 57.296 = 229.184 + 17 degrees = 246 degrees.
So, apparently the Zodiac Killer had some concept of radians and the value of Magnetic North, unless we are assuming he was just lucky in his placement of the bold circle on the diagram. His further reference to SFPD (San Francisco Police Department) next to this circle, suggests this is where we should be centering our focus, bearing in mind his disdain for law enforcement.
The Zodiac Killer wrote "The Mt Diablo code concerns radians + inches along the radians", so let us start with complete radians. We know from above calculations that the value of 4 radians (229 degrees) is significant, so we shall place a compass rose over Mount Diablo and see where this takes us, in respect of San Francisco.
4 radians = 4 X 57.296 = 229.184 + 17 degrees = 246 degrees.
So, apparently the Zodiac Killer had some concept of radians and the value of Magnetic North, unless we are assuming he was just lucky in his placement of the bold circle on the diagram. His further reference to SFPD (San Francisco Police Department) next to this circle, suggests this is where we should be centering our focus, bearing in mind his disdain for law enforcement.
The Zodiac Killer wrote "The Mt Diablo code concerns radians + inches along the radians", so let us start with complete radians. We know from above calculations that the value of 4 radians (229 degrees) is significant, so we shall place a compass rose over Mount Diablo and see where this takes us, in respect of San Francisco.
It can be seen that 229 degrees falls on the south edge of San Francisco International Airport by Old Bayshore Highway.
Was the Zodiac Killer intending to ratchet up the fear by exploding bombs (or the threat of bombs) in the vicinity of the airport? This seems highly unlikely, so we shall take a further look at the Button letter mailed on June 26th 1970, where the Zodiac Killer stated "The Map coupled with this code will tell you where the bomb is set. You have until next Fall to dig it up" and enter something alongside the code.
Was the Zodiac Killer intending to ratchet up the fear by exploding bombs (or the threat of bombs) in the vicinity of the airport? This seems highly unlikely, so we shall take a further look at the Button letter mailed on June 26th 1970, where the Zodiac Killer stated "The Map coupled with this code will tell you where the bomb is set. You have until next Fall to dig it up" and enter something alongside the code.
San Francisco International Airport is comprised of exactly 32 letters and fits squarely alongside the 32 symbol Button letter code. However, the 246 degree mark falls further around the circumference of the compass rose. The 4 radians took us to San Francisco International Airport, but coupled with the map "to be set to Mag.N" gives us the final value of 246 degrees. The San Francisco International Airport may have been the clue but not the final destination, which should lie in the Hunters Point region or beyond.
SEE PART TWO - http://www.zodiacciphers.com/zodiac-news/sfi-airport-part-two-hunters-point
SEE PART TWO - http://www.zodiacciphers.com/zodiac-news/sfi-airport-part-two-hunters-point
