There are now some tests that allow one to tell exactly what the origin of biological materials are through RNA but these tests are still highly experimental. Maybe in a few years they will become regular.
If you read the l literature on DNA, one cannot tell the origins of DNA - if it is blood, skin, hair, etc. What you wrote is nonsense. You are making Italian forensics to be the laughing stock of the world.
Generally, when the experts of the world in a specific field tell you that you are wrong, it might be best if you examine your own beliefs. If you examine your beliefs and argued that you are still right and give reasons, at least you are bringing a case. You are not even examining the counter arguments and just declaring yourself right.
Listen, there is nothing where I can be wrong in the post you quoted above, since what I am doing is just to explain English-speaking readers what a text in another language says.
Let's not start building strawmen about being wrong and right again, because you can see I am translating a text, not expressing an opinion on the matter.
It is a known fact that no one cannot tell the origin of DNA from simple DNA analysis.
And in fact, this is not what I am talking about.
I am showing: 1. how Berti and Barni apparently draw an inference about DNA originating from "biological fluids of Amanda Marie Knox";
2. how not just Stefanoni but all experts they do draw interpretations of findings, not just based on their discipline of expertise or applying Cartesian doubt, but also considering other external elements (the location of the finding for instance may be one of them);
3. how arguments like assessing the "likeliness" of the presence of Knox's blood, in fact may be developed upon reasons that just belong to the wider scope of the case file, and do not derive from the scientific discipline; they may well originate from some other unrelated evidence (such as suspect's lies for example); evidence and arguments not necessarily have to come from the subject of expertise of the witness: a case is to be judged by judges, not by expert witnesses.
4. the (some) "experts of a field" are not supposed to "tell me I am wrong", they are supposed to
convince me they are wrong, with argumentations, and this is a different task; in fact, they should convince a judge by undergoing cross-questionings. But you know something? The best, definitive contribute to my conviction that the knife and bra clasp evidence was sound, was provided by Conti and Vecchiotti; reading their flawed and fraudulent arguments, how they had absolutely nothing but that, it was like them putting an imprimatur seal as a further confirmation to my certainty. If they resorted to those arguments, it means that there is no other argument.
If you think you are about to make Italian forensic a "laughing stock", well, you are welcome to think that; meanwhile you may be interested in some critical reading about, let's say, defence expert "consultant" Bruce Budowle? Us Forensics methodologies? About for example, how Bruce Budowle's laboratory and FBI dept used to refuse to turn over the raw data about the tests they carred on?
http://www.nytimes.com/books/first/k/kelly-evidence.html
(...) This was not an isolated example. In several instances, when ordered to release the data underpinning its methodology the FBI refused. When it did release such data, particularly in the DNA sphere from 1989 onward, it was frequently found to be unscientific, flawed, and even downright false by a number of critical geneticists and microbiologists
In hearings beginning in 1989, Congress was being alerted to all this by a series of witnesses. One letter to Congressman Edwards cited the Arizona case and another in San Diego Superior Court, where the FBI had refused to turn over the raw data that formed the basis of the testimony of its testifying research chemist, Bruce Budowle