Yeh but the DNA from semen is nuclear. There's no ifs or buts. The DNA on the clasp was LCN and contamination in the machine in the lab.
Exactly. But then you'd have to have at least a passing knowledge of DNA typing to understand the important differences such as this one, plus the fact that it's not the time between the crime occurring and the DNA collection/testing that's important. Once the item carrying the DNA has been collected by the police, and assuming it's properly collected and stored (which in itself appears to be a challenge for the "crack" forensics team in this case...), then it could remain in storage for decades and still be equally reliable for the purposes of DNA typing.
But no, the old "46 day" thing keeps getting trotted out by various pro-guilt commentators as some sort of "gotcha". I can't decide whether it's sheer ignorance or vindictive bias that makes such people unable to understand that the important thing about the 46 days in the case of the bra clasp (and the reason why it's entirely incomparable to the decades after which correctly-stored items - which were originally collected and stored soon after a crime - are tested) is that
nobody knows what the heck happened to that bra clasp in those 46 days. During those 46 days, it was, without doubt, kicked around and covered in dust and debris, in a house where uncontrolled numbers of people - including burglars! - were coming through the premises and in and out of the room in which the clasp was found.
And anyhow, regardless of the 46 days, the most serious problems appear to have arisen on day 46 - the day when the clasp was eventually identified and collected by the "crack" forensic team on their return to the crime scene. I guarantee that no honest, experienced forensic investigator would fail to condemn in the strongest terms the way (documented on video for posterity!) that the clasp was handled with dirty gloves, handed around, placed again onto an unclean floor and treated like some sort of pass-the-parcel by the forensics goons. It further beggars belief that they didn't apparently even bother to test the exterior of Kercher's door for DNA (on the ludicrous premise that it was unimportant since it was the hallway-facing surface of the door!), when it was significantly likely that Sollecito's DNA may have been present on that surface and on the exterior door handle of that door.
But anyhow, back to the putative DNA stain on the pillow. Beyond all possible doubt, it should have been tested. There is zero downside to it being tested. I doubt it would be Kercher's boyfriend, since (IIRC) they only had sex in his room. And anyhow, it appears to have been wet at the time that Guede's shoe print was deposited, which appears to time it to around the time of the murder.
If that is the case, then if the stain is reliably Sollecito's semen, then he's guilty of murder (when you set this evidence against his version of events), and most courts would find Knox guilty of murder as well. And I personally would have no problem whatsoever saying: "Well now a reliable, credible piece of evidence has appeared, linking Sollecito indisputably to the murder scene, where there was none before. I now consider that he is guilty of participation in the murder, and by extension I believe Knox participated too."
If the stain is Guede's semen, then it DOES make a difference (as others have pointed out). It gives the lie, once and for all, to Guede's story of being a minor player caught up in someone else's horrible crime, and it also has material relevance to how and when Kercher was moved during and after the attack (she was moved by swinging her legs round clockwise shortly after she was stabbed, but was not moved again after death).
If the stain is someone else's semen altogether, then obviously the police and prosecutors should be looking for that person PDQ. And if it's not semen at all, well we're merely where we were before, and we haven't lost anything by conducting the test.
There's no rational argument for not testing this stain. None at all. Therefore one has to start wondering if there might be other reasons why the prosecutors seem so very reluctant to have it tested............