I feel compelled to address some
apparent misunderstandings in your post. My sense of compulsion is due to my having not understood the basis in Italian law about the calunnia charge and conviction for probably the first year after I became actively interested in the Knox - Sollecito case, and some of my confusion was not resolved until the ECHR judgment Knox v. Italy was published in 2019.
Firstly, under Italian law, certain wrongful actions, harmful to another, are subject to both a criminal charge and penalty (for example, a prison term, and a civil (tort) action with liability (an award to the victim or the victim's family). This is similar to US law, for example, murder is a crime with a criminal penalty and, as wrongful death, a tort with a civil liability (award for damages).
But there are differences between US and Italian laws and judicial practices. In the US, as far as I know, criminal and civil trials cannot lawfully take place at the same time before the same jury or the same judge. The following online reference supports that view:
pr
Source:
https://legalclarity.org/can-criminal-and-civil-cases-be-tried-together/o
However, in Italy, victims or the family of a victim of a crime have a choice: they can file an independent civil claim against an alleged perpetrator (the accused), or file that claim by joining the criminal trial; the victim's or the victim's family's civil lawyer becomes a private party lawyer (private prosecutor) working alongside the public prosecutor. Probably in part because Italian criminal trials can continue for extended times (indefinitely, for a murder, which has no statute of limitations), it is not at all uncommon for civil cases to be joined to their corresponding criminal cases, if there is one. The advantage for the civil party is that if the accused is
finally convicted, the civil party is awarded compensation damages from the accused (CPP Article 651). The disadvantage for the civil party is that if the accused is
finally acquitted, the civil party loses any right to collect any award from the accused, and cannot raise any subsequent civil action against the accused for the same act, provided that the reason for the acquittal is one of the following: the criminal act did not occur,
the accused did not commit the criminal act, or the accused had a legal duty or right to commit the act [such as self-defense] (CPP Article 652).
Thus, for the Knox-Sollecito case, the criminal case of murder was joined by a civil case brought by Kercher's family, and
the criminal case of calunnia (malicious accusation) was joined by a civil case brought by Lumumba.
Finally, there's the question of how the Italian courts reasoned to allow Knox's interrogation statements to be used against her in the criminal and civil calunnia trials (held together before the same judges but presented by a public prosecutor and private party lawyer, respectively), although the statements could not be used against her for the murder/rape charges because of the violation by the police and prosecutor of CPP Article 63, as stated by the CSC in an early ruling. The reason was not that there was a civil trial for calunnia, but because there had been an earlier ruling, in another (and subsequent) cases, by the CSC, that CPP Article 63
did not apply to spontaneous statements that were themselves criminal made during an interrogation. I learned this from statements made by Italy in the ECHR case Knox v. Italy. This is the Italian government statement, as presented in Knox v. Italy (Google translation):
Source:
https://hudoc.echr.coe.int/eng?i=001-189422