Hi guys, something that always bothered me was the fact that I heard and have heard many people say something to the effect that DNA was not really known about in the 60’s and was still in the realm of "science fiction". Forgive me if this is well-trod ground, I don’t want to get into a reinventing-the-wheel scenario but I had to prove this to myself.
A search of GoogleBooks periodicals confirms that not only did someone win the Nobel Prize in ’61 in DNA research, but it was clearly a matter oft-spoken of in the scientific community, particularly in the biological sciences community. I found a large number of articles from the early 60’s talking about how personal characteristics are "mapped out" in the DNA strands, and to me, being that NO DNA was found on the envelope flaps of the three letters, makes me suspect that Z indeed was quite on top of the newest research in the sciences- or even just had a passing interest. Being that one of these magazines was a Popular Science mag from May, 1963, anyone could have read that and gleaned quite a bit from these and other articles that are strewn throughout. I found this really interesting, considering that a certain someone MAJORED in biology with a minor in chemistry. Even if it is not him (and we all know who I am referring to) I was happy to nail that down firmly for myself. I will upload an article or two if anyone likes, but its all there in GoogleBooks.
Living in the 21st century has given us FAR more resources than even the most sophisticated LE back in Zodiac’s day.
I know that you are implying that Zodiac could have known about DNA and so therefor he could have taken steps to make sure that he didn’t leave any behind…maybe. But supposing that he had, I would call that idea pretty ridiculous.
Why? because DNA wasn’t used in criminal cases for another two decades. He didn’t really need to bother. And people continued to leave it behind until then and still do until today. I don’t deny that it’s possible he did not leave DNA, but I really doubt it was because he intended to do so because he was worried about getting IDed by it.
There was no DNA found on the first three envelope flaps. No biological material AT ALL. Which, unless the FBI lab is wrong, someone used water to moisten them. Also no fingerprints on those letters. The only letter that has any fingerprints on it at all is questionable to many.
This shows intelligence beyond what I think people have accredited.
The fact is that he obviously someone who knew about bombs, which implies even a rudimentary knowledge of chemistry, and certainly the use of "radians" and "mag north" implies a knowledge of surveying, and I have studied surveying myself. He knew trig and knew about magnetic declination. He knew (as anyone in that field would have known) that Mt. Diablo, which he clearly encircled on the Phillips 66 map, is used as a reference point for navigation and mapping. He took extra care to let people know that Mt Diablo was important.
Even if this guy was not deeply studied in the sciences, even if he never got a degree, he certainly had a fascination with these things, numbers, ciphers, mapping. A guy like that would probably be reading "Popular Science". He would have known about these things. And the essential thing about the Zodiac is that he wanted to be larger than life. He wanted to believe that his crimes would never be solved. He was playing a psychodramatic game with the world. He believed in covering up every physical trace. And saliva had already been found to show blood type, and mystery and crime stories from the 40’s on abound in such asides about people being caught by physical traces. There was even one case I found in the mags from the 40’s about a killer who left a cigarette butt behind and a forensic analyst determined the blood type of that individual and it helped convict him. So even if DNA was not something on the table explicitly as a crime-solving tool yet, saliva MOST CERTAINLY was, and the IDEA of DNA being a microscopic building block of a total person, able to be replicated, was something that was just being put ON the table.
I also know that the sciences were accelerating at such a rate that it would not have been at all a stretch of the imagination to think that a paranoid, egocentric, yet deeply cowardly killer would want to hide all physical traces of himself. And I have heard that mentioned at least a hundred times in forums as a reason to believe wholesale in the DNA, that "nobody would have thought to cover these traces since nobody knew about DNA". And that is just simply WRONG.
I think you have a point, mysterymachine.
He may very well have been more or less up to scratch on forensic science. The existence of saliva testing was well known – and you didn’t have to be a learned man in order to know about it either, a reader of detective literature might have come across it easily. And that’s sufficient reason right there why he didn’t lick the envelopes – which he doesn’t appear to have done.
It’s not a possibility which excludes or includes anyone, really – but I think it’s a possibility one should keep in mind. He might have been very careful not to leave a trace behind – and if nothing else, the latter assumption certainly goes well with the fact that none of the physical evidence we know about seems to be undeniably connected to Z.
All Zodiac had to really know about is Locard’s exchange principle….and that goes way back.
I doubt DNA traces were on his mind though.
“…they may be dealing with one or more ersatz Zodiacs–other psychotics eager to get into the act, or perhaps even other murderers eager to lay their crimes at the real Zodiac’s doorstep.“ L.A. Times, 1969
All Zodiac had to really know about is Locard’s exchange principle….and that goes way back.
I doubt DNA traces were on his mind though.
Precisely – very good point. And Locard’s principle was known to crime writers of all kinds and qualities, I’m sure. If I’m not mistaken Locard is cited by the likes of John Dickson Carr and Chesterton – maybe even Agatha Christie herself.
DNA as such wouldn’t have been on his mind – I agree. I don’t think that concept had entered the mainstream much back then.
Yes, I agree, guys, that probably he wasn’t thinking "they can tell who I am by my DNA". But the saliva is another story. And certainly it might have crossed his mind that they would have been able to find out more down the line since biology was progressing so rapidly.
And you are right Norse, it doesn’t include or exclude anyone, at all. In fact it is actually a bit MORE depressing since the possibility that there is NO DNA (at least a full profile) on those letters means—-he never gets caught.
I think myself and many others wanted to believe that the DNA was gonna be the big round-up, the nice bow to tie it all up with. The fact that this is not the case is infuriating.
