#2. Found by a janitor in December 1966, written inside a foldable desk at the Riverside City College Library was a foreboding poem, part of which read "blood spurting, dripping, spilling all over her new red dress. Just wait till next time. rh". Was next time three years later. Betsy Aardsma was wearing a red dress on the day she was killed, that temporarily disguised the severity of her injury. Was this poem a dormant fantasy by the killer that he later enacted.
#4. Reviled by many, Richard Haefner had anger issues. Excerpt from the Lancaster online: 'Haefner told investigators he'd found out about her death the evening of Nov. 29, a day after she was stabbed. But in fact, Skucek asserted, Haefner knew of the crime shortly after it was committed. He'd shown up at the home of a professor just hours after Aardsma was killed, asking, "Have you seen the papers?" The stabbing had not yet been reported in the local newspapers. But Haefner knew about it and "expressed concern about what had happened to this young lady," the professor told Skucek.'
Death Valley is situated just over 200 miles north of Riverside. Richard Haefner was born in 1943 and would have been 23 years of age in 1966.
#6. Wikipedia: The Sonoma Volcanics are a geologic formation of volcanic origin that is widespread in Napa and Sonoma counties, California, with the presence of rhyolite tuffs, described in Death Valley. Had Richard Haefner visited Sanoma County too.
#8. A highly controversial letter was mailed in 1978, alleging it was from the Zodiac. It began with the words ' This is the Zodiac speaking. I am back with you'. On November 28th 1994, exactly 25 years after Betsy Aardsma's murder an employee of the library found a candle had been lit and placed in the location of the murder. A message written on the floor using a marker pen said 'RIP Betsy Aardsma, born July 11th 1947, died November 28th 1969. I'm back'. Also a postcard had been mailed to police sometime in the 1970's with the wording 'You never did catch the guy who killed that **** in the library '.
#11. The Zodiac referred to radians in his correspondence and included a map of San Francisco and Vicinity. Richard Haefner used mapping in geology and was familiar with detailed measurement. Wikipedia: "The gradian is a unit of measurement of an angle, equivalent to 1/400 of a turn, 9/10 of a degree... only adopted in some countries and for specialized areas such as surveying, mining and geology. ... In the 1970's and 1980's most scientific calculators offered the grad as well as radians and degrees for their trigonometric functions."
#12. The November 8th and November 9th 1969 Zodiac communications claimed 7 victims. The Melvin Belli letter on December 20th 1969 sought a ninth and possibly tenth victim. Therefore by deduction his eighth victim must have been killed somewhere between the two dates. Betsy Aardsma was murdered exactly bisecting these two dates, on November 28th 1969. The Fairfield letter mailed on December 16th 1969 depicted the 'Bleeding Knife of Zodiac'. Eight drops of blood are visible dripping from the knife.
It is fairly easy to compile and manufacture links to an individual, and present only loose circumstantial 'evidence'. This took a few minutes, but with more time could be easily be expanded to #20+. Richard Haefner was almost certainly not the Zodiac Killer.