So you think the contamination was airborne? With the technicians working there every day, other samples from other cases and so forth and allegedly 6 days since the previous Meredith sample was tested it just seems like astonishingly bad luck to me. We clearly differ on this and I'm not going to push it. It's the bra clasp all over again. To me it's surprising that of all the dust in the house Raffaele's dust should make up such a large proportion of the contamination (assuming we go with the dust theory), other people aren't surprised in the least.
Really, if LCN levels DNA was floating about in the way you seem to be describing no LCN DNA analysis would be possible. The knife would already have been hopelessly contaminated with Raffaele's DNA from the air in his flat.
That's why special materials and special labs are needed to handle Low Template analysis, and why
standards have to be employed so that things like this don't happen. Stefanoni's results were never legitimate, that's what the
neutral independent, qualified, court-appointed experts actually said. If you came to a different conclusion, you were listening to the wrong people and choosing the wrong information in which to base your decision. Just because the prosecution disputes the
fact they were caught cheating doesn't mean that
fact is legitimately in dispute! Especially since it was dismissed as irrelevant or untrue. Did you actually expect them to fess up? Or does their previous behavior suggest they're more likely to misdirect, obfuscate and accuse? Why would they be honest if they made a mistake when there's no penalty for lying and anyone suggesting misconduct may be jailed or sued?
It appears to me you started from your conclusion and worked backwards. That the bra-clasp and knife were legitimate, thus anything else had to be proven. In actuality those pieces of 'evidence' were so absurd a cursory inquiry might have suggested to you a different tack. Evidence of four or more contributors, which is easily determinable by perusing the source material, is
highly suggestive of illegitimacy on many levels. That it is considered evidence in an Italian court is an indictment of that court, not the analysis. That knife is so ridiculous on so many levels, it by itself implies a disingenuous prosecution. Entry level forensics and science don't change from place to place, thus they're a handy barometer in instances like this.
So try starting from the only assumption that is valid at this point, that the knife has to be
proven to have been part of the murder. Not that it's the murder weapon until proven otherwise, because it appears that has caused you to get lost in a decaying faulty logic loop. Now let us say you're looking at it under the assumption that you have Stefanoni's results, why not take a look at what those promoting forensic
LCN/LT DNA say about the standards imposed and procedures that must be employed to ensure proper results?
Here's something of a primer on forensic DNA work to start with so you might have an idea WTF they're talking about in the first one.
Then stop and think about the falsifiers and indications it wasn't involved in the murder. No blood traces, not matching the wounds--and
why it doesn't--that it was supposedly the only trace of Amanda that could be connected to the murder room, that there were no wounds on Amanda, nor anything on her body or clothes found suggesting participation in a violent death struggle.
Now think about the fact that a bright guy like you can simply assume it's the murder weapon because they say so, that the prosecutor can produce whatever he damn well wants to in court as 'evidence. ' Add in the fact that the jury of an Italian trial of the first instance can be populated by those without high school educations and might be even more prone to just assuming because the prosecution says so it must be true, and the defense must conclusively disprove any dispute the prosecution makes to their rebuttal, but they don't have to actually
prove anything and can jail or fine anyone who suggests impropriety.
Why, under those conditions they could probably propose anything they wanted as 'evidence' of murder and get away with it, couldn't they? So why not start from the beginning and evaluate their contentions on the basis of logic, science and forensics? Maybe even employ some common sense as well?
Here's something that might be very helpful in determining the status of the knife and bra clasp, if you find you have to violate it to a
ridiculous degree to determine it was the murder weapon--
if you can even do so by starting at the beginning--then perhaps the better explanation is that it wasn't used in the murder, and the fact they even proposed it as such goes a long way towards
explaining this? 
