It is a principle well established in the jurisprudence of the Court of Cassation that the judge of appeal has the obligation of renewing the trial phase any time it interprets the evidences collected in the proceeding of first instance in a completely different manner and, thus, reforming in peius the earlier verdict. This interpretation derives from the ECHR Court jurisprudence of the right to a fair trial (Article 6 of the ECHR) and from the fact that Italian judges have an obligation to conform to the interpretation given to the ECHR provisions by the ECHR Court (judgments of the Constitutional Court No. 348 and 349 of 2007). By contrast, renewing the trial was deemed not necessary when the appeal judgment is more favorable to the accused. In decision No. 41571 of 20 June 2017, the Court of Cassation (II Criminal Sections) stated that also when the appeal decision is not reformed in peius, the trial phase must be renewed, in order to prevent a violation of the fair trial principles to the prejudice of the injured party.
Decision of the Court of Cassation, United Sections, No. 27620 of 6 July 2016; Decision of the Court of Cassation, United Criminal Sections, No. 18620 of 19 January 2017