Why did the police and prosecution arrest, or wage a long, wrongful prosecution against Amanda Knox and Raffaele Sollecito? There are several possibilities, and only one of these possibilities seems to have been emphasized by Moore and Clemente and some others. Here is a brief listing, as I understand the possibilities:
1. The police, seeing the break-in involved a rock thrown through a window and a climb to a second story, recognized the MO of Rudy Guede, a (supposed) police informant (or person otherwise protected, such as by his (former?) relationship to the wealthiest and most powerful family in Perugia. Therefore, they sought to direct attention to Meredith's close associates as suspects.
2. The search for convenient suspects. The police saw the break-in and decided it would be a troublesome effort to attempt to solve the case by seeking anyone who might actually have committed the crime that way. So they recognized, as amoral, unprofessional police do, that they should concentrate on finding someone close to Meredith who would be vulnerable to suspicion, for example, by having a relatively weak alibi, and/or by being liable to be portrayed as "strange" or "evil" or "just a foreign slut".
3. The police had reason to suspect Amanda Knox of the crime because of her odd behavior. She apparently, according to Dr. Giobbi (see his testimony), wiggled her hips while putting on shoe-covers. She cried and/or she didn't cry. She had an Italian boyfriend who she had known for only a little more than a week, and stayed overnight with him, and he seemed interested in her, even coming to the police station to see her. Only the boyfriend was her alibi for the night of the murder. And she had the keys to the apartment. (Some of this may seem like case #2.)
4. The police were just really incompetent and lazy.
5. As a corollary, the prosecution had to continue to protect the police from being accused of a criminal act (CP 377-bis. punishment 2-6 years in prison) because of the "special methods" they used to extract a statement from Amanda Knox during the interrogation of Nov. 5/6, 2007, when they "knew" she was guiltly of something. Evidence that the police and prosecution were certain Amanda was accusing them of a criminal act: She was accused of calunnia against the police by Dr. Mignini in 2009. "Calunnia" as a legal term in Italy means to falsely accuse - to the police or a judicial authority - someone of committing a crime.
We've been kicking these ideas around for a while, so I'd just like to inject a few ideas I hope we could agree on.
1. SOCIAL PRESSURE - There was enormous pressure on the police to resolve this crime. Pressure from the media coverage, and pressure from the local authorities and business community. The local economy was heavily dependent on students spending money, and they were fleeing in droves. Every day was a worsening calamity. Panic on the police's part to solve the case asap, does not make for the best decisions or most careful work.
2. INEXPERIENCE FORENSIC TEAMS - Perugia police had not much experience in murder, much less high profile crimes. Stefanoni had to get permission to be both crime scene inspector and lab tech, losing a level of independent review that might well have avoided this miscarriage of justice had that separation of powers been maintained.
3. PROFESSIONAL STAKES - Mignini himself, along with his former colleague Michelle Giuttari, had just then been indicted for trial relating to excesses in office relating to their investigation and prosecution of the 'Narducci Trail' cases, an offshoot of Giuttari's 'satanic sect sex orgy murder theory' relating to the Monster of Florence crimes.
Mignini immediately characterized the Kercher crime as being of the same type, a multi-attacker sex crime related to the "rites of Halloween". Mignini had been in communication with Carlizzi from day 1 of the crime, and sought to portray the crime in eerily similar language to Giuttari's description of the "satanic rites" he alleged (bogus-ly) were at issue in the Monster of Florence crimes.
4. CONTINUITY OF FRAUD FROM MOF CASES- Giuttari was principally responsible for trumping up the false convictions of Vanni and Lotti as accomplices to the innocent Pacciani for the Monster of Florence murders, and doing so with the assistance of his four bogus tramp 'algebraic witnesses'.
5. GIOBBI & GIDES - Giobbi came in from Rome, on the first day of the crime scene. Mignini had characterized the crime as fitting into the pattern that Guittari's GIDES unit (the special unit formed to pursue the "masterminds" behind the satanic sect they believed responsible for the MOF crimes). Giobbi & Mignini may not have been looking for a single perp, but rather looking for a multi-attacker conspiracy. Manufacturing another group murder satanic sect case would be another feather in the cap for them all.
6. While Mignini incarceration of Spezi and unauthorized investigation of other journalists and officials led to the indictments for abuse of office, Mignini had already pressed ahead with his next 'satanic sect case' against the Florence pharmacist Francesco Calamandrei. In the Calamandrei case, Mignini relied on the same four bogus 'algebraic witnesses' provided by Giuttari.
Mignini also relied on an associate of Carlizzi who gave testimony against Spezi, that Mignini kept under seal using special anti-mafia/terrorism laws to keep that testimony and its source secret.
7. Rudy Guede had a history of burglary, appears to have eluded prosecution, and received assistance when busted in Milan, to enable his return to Perugia on the next train. There is a strong possibility Rudy was an informer, and I would say it is a certainty he was an low level criminal with a pattern of similar breaking and entry, habitating crime scenes, and brandishing a knife when confronted during his crimes. Napoleoni acknowledge the police were familiar with Guede from his burglaries in Perugia before the murder, so that seems to be worth/justify exploring what Napoleone meant by that.
Hoping this post wouldn't bloat, so I'll end it here.
The point is, Mignini madness must be considered a factor as well. The prosecutor in his abuse of office case described him as having "
fallen prey to a kind of delirium". So demanding a logical train of thought from the Perugians, is not necessarily justified.