Since 2018, the Vallejo Police Department has allegedly been working to develop DNA from some of the Zodiac evidence. To date, all there is to show for it is rumors from various allegedly informed sources about possible ongoing genealogy work that is taking years, not months, to complete with no end in sight.
The real issue is that the public is completely uninformed as to where the DNA they are using (assuming it does exist) even comes from. The last thing we need is a high-tech repeat of the cataclysm of 2002, when my suspect was ruled out on national TV against a sample that never should have seen the light of day as even allegedly being "Zodiac DNA."
I feel that the public deserves to know if any DNA they are using for genealogy research comes from multiple letters and comes from areas of the letters that would be expected to have DNA from the sender. But as usual, the police are operating under the cover of darkness and behind a curtain of secrecy that shields what they are doing from both Zodiac researchers and the public in general.