I believe most readers here understand that in the Knox - Sollecito case, there had been a court case against prosecutor Mignini alleging that he had committed a criminal act of abuse of office in the Monster of Florence case. The charges againn st Mignini were dismissed when the length of the trial exceeded the time limit allowed under Italian law. Thus, under Italian law, Mignini's status is equivalent to having been acquitted of those charges. However, in the MoF case, and later in the Knox - Sollecito case, Mignini showed a strong tendency to view the relevant crimes as the product of satanic rituals and conspiracies, but without providing credible evidence.
In the Knox - Sollecito case, Mignini's acts, or failures to act, included failures to follow critically important Italian laws of criminal procedure. For example, he interviewed Knox after her police interrogation without warning her that she was now a suspect, that she was entitled to a defense lawyer during the interview, that she had the right to remain silent, and that anything she said against another person would make her a witness - apparently a warning about the crime of calunnia (CPP Articles 63 and 64).
Mignini and the police failed to provide the required warnings to Sollecito as well, and in 2017 the High Council of Magistrates censured Mignini for not providing Sollecito with a lawyer or warning him of his need for one.
The CSC had, at an early phase of the case, ruled that, because she was not provided a defense lawyer during the interrogation, Knox's statements during the interrogation could not be used against her (which, by some other CSC ruling, was only considered applicable tor the murder/rape case and not the calunnia case).
In the ECHR judgment Knox v. Italy, the ECHR found that Knox's lack of a lawyer during the prosecutor's interview, while she was without any doubt a suspect, resulted in a violation of Convention Article 6.1 with 6.3c, and made the entire trial and conviction for calunnia unfair beyond repair. The ECHR found that the earlier interrogation by the police resulted in a violation of Convention Article 6.1 with 6.3e, because of the inadequate and unfair nature of the interpretation, and likewise made the entire trial and conviction for calunnia unfair beyond repair.
Some readers here may wonder whether the police misconduct in this case was the result of mistakes or intentional. The police violated several important basic procedural laws, such as documenting the actual questions and answers, including the statements of the interpreter, during the interrogation. For Knox's interrogation, they failed to follow the requirements of CPP Article 63, which requires the interviewing police to notify the alleged witness that she has made an incriminating statement, that she is now a suspect subject to investigation, and that she is now entitled to a defense lawyer. No further questioning is to be conducted without the defense lawyer present. According to Knox's testimony in court, the police threatened her and hit her on the head during the questioning; such conduct would be a violation of Italian criminal law.
Some readers may have an idealized view of police, including those who questioned Knox and Sollecito, and consider that the police would not violate criminal or even procedural law. However, two of the police officers, Monica Napoleoni, head of the homicide squad, and Stefania Zugarini, her subordinate, who questioned Knox during 2007 interrogation, were convicted in 2020 of an abuse of power. They had illegally used the police computerized information system for Napoleoni's non-police-related effort to find information about a psychologist who was working on matters related to Napoleoni's divorce. Napoleoni was also convicted of vandalizing the psychologist's car. These convictions may suggest that some of the police at the interrogation were willing to violate criminal and procedural laws in pursuit of their goals.