OK, I didn't mean to offend you. I was just asking.
Well, like I say, the subject has been explored quite extensively. However, a few of the things that have jumped out for me are...
Pretty much from the outset, the investigation seems to have been premised on the absolute assumption that Knox was guilty. The problem with that is, if you start your investigation with a mind that is closed to other possibilities, you won't see them even if they're there. As her lawyers put it, the investigation was a "ship that never changed its course". In all but the most open-and-shut cases, there are usually things that crop up in the course of an investigation that don't neatly fit the initial assumptions about what happened, but seemingly not here.
Secondly, the way in which - in particular - Knox was interrogated was asking for trouble. When you start doing all-night interrogations on people, don't be surprised when they start saying strange or stupid things. When that is added to a pretty brutal process of investigation of Knox, it doesn't seem unreasonable that she might be disorientated, confused, stressed, etc.
Thirdly, they had already identified Knox and Co as suspects before they even knew about Guede. But even when they'd found out about him, they carried on on the assumption that it must still have been them, only involving Guede as well. It would have been wise not simply to close one track of the inquiry after having discovered a completely new track, but it looks very much as if they simply tried to weave Guede's actions into the ones they had already surmised had taken place with Knox et al.
Fourthly, evidence seems to have been rather prone to mysteriously appearing: while the fact that the bra clip was missing for nearly seven weeks isn't itself particularly remarkable, its appearance at a remarkably opportune time does seem rather unusual, especially since...
Fifthly, the investigating magistrate and prosecutor in this case has a bit of previous for desperately weaving complex threads of evidence into this theories about crimes he's investigating.
Sixthly, the DNA evidence is uncompelling - there are claims that the victim's DNA was found on a knife belonging to Knox, but the traces were very small, and not entirely conclusive. Given the long history of contamination problems with DNA evidence, it's generally recognised that one of the biggest problems with it is the risk of contamination, either from police, or from cross-contamination with other evidence if not handled very carefully, or from circumstances unrelated to the crime. Given the sloppiness of so much of the police procedure - after all, they were pretty definite that Knox was guilty from the outset, so why worry too much about anything? - I don't think it is impossible that the DNA evidence might have been contaminated, either accidentally, or perhaps even to reinforce what the investigators already "knew".
Seventh, while plea-bargaining is by no means unusual, the way in which the authorities set out to do this with Guede seems strange. He, after all, had little to lose - he was in the frame for a nasty murder and looking at 30 years inside. You'd have to be a very moral person indeed not to consider the prospect of reducing that somewhat by putting someone else in the frame. And, from the sound of it, the investigation was sufficiently inept (or corrupt) that Guede was able to identify the people whom the police
just happened to have as the main suspects as his co-conspirators.
None of this is to suggest that Knox is either guilty or innocent. But the investigation, in attempting from the outset to convict Knox and Sollecito, almost certainly failed to take opportunities to build up a solid, non-partisan body of evidence, and have effectively destroyed any chance that the full truth might be known. Guede, it seems, has been safely convicted, and it may even be that he was the sole party responsible. But, in conducting the investigation the way they did, the authorities in Italy have sown doubt that might possibly never need to have been sown, and eliminated any possibility of clearing up that doubt.
Everybody loses - the Kercher family, because they can never know exactly how their daughter died; Knox and Sollecito, because they can never prove their innocence, and the Italian authorities, for making such a public mess of a very high-profile case with international implications.