The Right to Contradictory Proceedings and Expert Opinions on Appeal: The Important Ruling 20374/2025 of the Court of Cassation

In the Italian legal landscape, the protection of the right to contradictory proceedings is one of the fundamental pillars of a fair trial, guaranteed not only by our Constitution (Articles 24 and 111) but also by the European Convention on Human Rights (Article 6 ECHR). Every party to a legal proceeding must have the opportunity to participate actively in the formation of evidence and to confront it. The Court of Cassation has recently expressed its opinion on this principle with ruling no. 20374, filed on June 3, 2025, annulling a previous decision by the Court of Appeal of Bologna for defects related to the reopening of the investigation.

The Context of the Decision: Expert Opinions and Technical Consultants

The legal proceedings involved S. B. and S. P., with the Public Prosecutor's Office represented by Dr. S. S. The ruling in question, drafted by judge B. F. L. and presided over by A. M., addresses a crucial aspect of criminal proceedings, namely the management of technical evidence on appeal. Specifically, the Court of Cassation ruled on the legitimacy of the failure to admit, as contrary evidence, the examination of the civil party's technical consultant on the conclusions presented by the expert appointed at that stage. The Court of Appeal of Bologna had omitted this step, leading to the annulment of its judgment, albeit only for civil effects.

The focal point of the issue lies in the necessity of ensuring that all parties have the opportunity to interact with and challenge the findings of an expert report or technical consultation. When an expert is appointed by the judge to provide technical assistance, their conclusions can have a decisive impact on the outcome of the trial. For this reason, the legislator and jurisprudence have always emphasized the importance of allowing parties to present their own technical consultants, who can refute, supplement, or clarify aspects of the court-appointed expert's report.

The Ruling's Headnote and Its Meaning

In matters of reopening the investigation on appeal, the failure to admit, as contrary evidence, the examination of the civil party's technical consultant on the conclusions presented by the expert appointed at that stage gives rise to a general nullity of intermediate regime pursuant to art. 178, letter c), of the Code of Criminal Procedure, constituting a violation of the party's right to contradictory proceedings regarding the evidence.

This headnote crystallizes a principle of fundamental importance. The Court of Cassation clarifies that denying the civil party (or any other party) the opportunity to question their technical consultant regarding an expert report prepared on appeal constitutes a violation of the right to contradictory proceedings. This violation is not a mere irregularity but a genuine nullity. Specifically, it is a general nullity of intermediate regime, pursuant to Article 178, letter c), of the Code of Criminal Procedure.

But what exactly does "general nullity of intermediate regime" mean? Nullities in criminal proceedings are distinguished as general and special. General nullities are provided for by art. 178 of the Code of Criminal Procedure and concern serious defects that compromise fundamental guarantees. Intermediate regime nullities are those that, while serious, must be raised within specific time limits (e.g., before the deliberation of the first-instance or appellate judgment, if they occurred at that stage), otherwise they are cured. In this case, the violation of the right to contradictory proceedings is considered so serious as to fall within those affecting the rights of defense and the participation of parties in the evidence, rendering the flawed act null and void.

Practical Implications for Criminal Proceedings

Ruling 20374/2025 strengthens the position of parties in criminal proceedings, particularly when technical evidence is involved. Here are some key points to consider:

• Right to Counter-Evidence: The unconditional right of parties to present their own technical perspective, including through the examination of their technical consultant, against the conclusions of the court-appointed expert is reaffirmed.
• Role of the Party's Technical Consultant: The party's consultant is not a mere passive "controller" but an active participant in the evidentiary dialectic, whose voice must be heard.
• Reopening of Investigation on Appeal: The reopening of the trial investigation on appeal (governed by art. 603 of the Code of Criminal Procedure) must be conducted in full respect of contradictory proceedings, avoiding preclusions that could limit the parties' defense.
• Consequences of Violation: The failure to admit the examination of the party's consultant results in a nullity that can lead to the annulment of the judgment, with significant consequences for the continuation of the proceedings, as occurred in this specific case with the annulment for civil effects.

This pronouncement serves as a warning to trial judges to pay the utmost attention to respecting procedural guarantees, especially in delicate phases such as the reopening of the investigation on appeal, where the formation of evidence must occur transparently and with the participation of all parties.

Conclusions: The Protection of Procedural Guarantees

The Court of Cassation's ruling no. 20374/2025, by annulling the decision of the Court of Appeal of Bologna, forcefully reiterates an indispensable principle of our legal system: the right to contradictory proceedings. The ability for parties to examine their technical consultants in relation to court-appointed expert reports is not a mere formality but a substantial guarantee for the correct formation of evidence and for the protection of defense rights. A fair and just trial necessarily involves the full and equal participation of all parties in the construction of the evidentiary framework, especially when dealing with technical assessments that require specific expertise and careful critical evaluation.