One letter read "Dear Sir, I am sorry I cannot give my name for obvious reasons. I am the Ripper. I've been dubbed a maniac by the Press but not by you, you call me clever and I am. You and your mates haven't a clue that photo in the paper gave me fits and that bit about killing myself, no chance. I've got things to do. My purpose to rid the streets of them sluts. My one regret is that young lassie McDonald, did not know cause changed routine that night. Up to number 8 now you say 7 but remember Preston '75. get about you know. You were right I travel a bit. You probably look for me in Sunderland, don't bother, I am not daft, just posted letter there on one of my trips. Not a bad place compared with Chapeltown and Manningham and other places. Warn whores to keep off streets cause I feel it coming on again. Sorry about young lassie. Yours respectfully, Jack the Ripper.
Might write again later I not sure last one really deserved it. Whores getting younger each time. Old slut next time I hope. Huddersfield never again, too small close call last one."
Yet here we are, thirteen years later, waiting in expectation once again, despite having a possible 30 letters at our disposal and numerous double postage stamps available for testing. Whether or not the Zodiac envelopes and stamps were licked by the killer and contain enough traces of saliva, if at all, should not be an argument in 2018. The Golden State Killer case may have jolted the investigation around the Zodiac Killer into life, with the use of familial DNA testing - but this scientific advancement is nothing new, having been available through current DNA databases for years. The use of familial DNA testing in the USA has been bedeviled with privacy issues, currently adopted by very few states in America, including California.
There is a possibility that besides the July 31st 1969 letters and others, the items recovered from Lake Berryessa may contain the Zodiac Killer's blood. Often during bladed attacks, the assailant will cut themselves and deposit blood at the crime scene. By all accounts Bryan Hartnell played dead to avoid further repeated stabbing, but unfortunately Cecelia Shepard did not adopt this strategy and hence sustained greater knife injuries to her back and abdomen. If the Zodiac had knowingly left while under the impression one person was still alive, then had he cut himself during the latter part of the attack as the knife became sodden with blood, not dissimilar to the murder of Cheri Jo Bates in Riverside on October 30th 1966. If so, this may provide investigators with the possibility of testing for DNA on the clothing and blanket recovered from Lake Berryessa on September 27th 1969.
On June 9th 1984, Melanie Road, 17, was stabbed to death in Bath, Somerset, England. She had been brutally stabbed 26 times. "A trail of blood matching Hampton's blood group, and later his DNA, was found leading from nearby St Stephen's Road in the direction of his home half a mile away." Independent. It was entered into the UK database.
Thirty years later his daughter, then aged 41, was arrested for a domestic incident, leading to a familial DNA match to the genetic fingerprint stored in the database. Christopher Hampton was jailed for 22 years in 2015.
Privacy issues have been argued over the recent Golden State Killer case and aggressively pursued in many American states regarding the use of familial DNA to trace offenders. The same issues have arisen over the use of CCTV trailing our every move. One can ask yourself the question - if the killer of your mother was captured on CCTV or through familial DNA testing, would you argue against its use when it helps you, or only argue against it when it helps somebody else.
If you think the DNA in the Zodiac case is too old and degraded, then think again. Detectives in the 'Little Red Riding Hood' murder of 12-year-old Muriel Drinkwater from Swansea in 1946, extracted DNA from a semen stain on her coat in 2008. This has been touted as "possibly the oldest one in the world to be successfully extracted in a murder investigation. In 2008, a team of retired detectives investigating cold cases found Drinkwater's clothes in storage. Her blue coat, her underwear and school uniform had been wrapped in a paper bag and stored. On the back of the coat, a no-longer visible semen stain was circled with yellow crayon. Scientists successfully retrieved a DNA profile from the stain on the coat. A familial DNA profile was extracted using a technique called Y-STR, but no match was found in the national DNA database. Hubert Hoyles, who saw her after buying eggs at her parent's farm, was cleared by the DNA evidence. He stated he had long been suspected by some locals as the murderer and was happy to clear his name." Wikipedia.
It seems rather odd to now claim with renewed optimism, the possibility of generating a full and complete DNA fingerprint of the Zodiac Killer, when this possibility has been there for years. The recent likely capture of the Golden State Killer has given a much needed 'kick up the backside' to the Zodiac investigation. But it shouldn't have been required.