None of these events would have transpired but for the diligence of Ken Williamson, who would ultimately inspire the last puff of defiant hot air from the Zodiac Killer before he was shamed and discredited into anonymity. He may have got away with claiming the abduction of Kathleen Johns, the murder of Richard Radetich and the disappearance of Donna Lass by virtue that none of these crimes had been solved. He was gifted the murder of Cheri Jo Bates by the column inches of Paul Avery - and not surprisingly accepted this gift with open arms, before throwing in a few more unnamed murders for good measure. None of which he revealed any information only pertinent to him and the police. He was only too willing to supply extra details in the July and August of 1969, make phone calls to the police after his second and third attack, write on a car door by a lake and send a bloody piece of shirt to the San Francisco Chronicle - yet any evidence thereafter was sadly lacking.
The dying fumes of the Zodiac Killer may have transpired in the latter months of 1971, or early months of 1972, when the Zodiac Killer was driven to communicate to the chairman of the DMV in Sacramento. A communication facilitated by the excellent work of Ken Williamson, whose 'vehicle license plate' details of Karl Francis Werner, resulted in the police identifying the home address of Werner at Shawnee Lane in San Jose and his eventual arrest. Bearing in mind the Zodiac Killer had directly and indirectly included San Jose in a total of five communications to date, with two consecutive ones in 1971, then it wouldn't be too surprising if the one mailed to the DMV in Sacramento (likely in the November or December of 1971) had a San Jose connection also.
The Zodiac Killer, probably in one last throw of the dice, sent a letter to the chairman of the DMV in a desperate attempt to reclaim some lost pride. It likely read as follows "I am the murderer of the two kids in San Jose in August and the girl on the 11th of April near the park in Saratoga. I drove away quite slowly from both crime scenes so as not to draw attention to my car. Stop listening to phonys". Yet, on this occasion he couldn't supply any extra details known only to him and the police, finally bringing the Zodiac Killer's unabated fortune of claiming unsolved crimes to a crashing halt - and thereby exposing him as the real phony that many suspected he always was. The Zodiac Killer's race was run - and Ken Williamson was the architect in his unthroning.