Appeal to the Supreme Court and Expert Evidence: The Interpretation of Judgment No. 9455/2025

The Italian judicial system is a labyrinth of rules and interpretations, where every judgment of the Court of Cassation serves as a compass to guide legal professionals and citizens. A recent ruling, Judgment No. 9455 of 07/03/2025, fits precisely into this context, offering a fundamental clarification on a crucial aspect of criminal proceedings: the possibility of appealing to the Supreme Court for the failure to admit expert evidence. This decision, presided over by Dr. P. P. and drafted by Dr. D. L., declared inadmissible the appeal filed against a judgment of the Court of Appeal of Naples, providing important food for thought on the limits and conditions for the admissibility of grounds for appeal.

"Decisive Evidence" in an Appeal to the Supreme Court: A Delicate Boundary

An appeal to the Supreme Court, governed by Article 606 of the Code of Criminal Procedure (c.p.p.), represents the final level of judgment, aimed at verifying the correct application of the law. Among the grounds for appeal, letter d) of paragraph 1 allows for challenging a judgment for the "failure to admit decisive evidence." But what exactly is meant by "decisive evidence"? Judgment No. 9455/2025 addresses this issue precisely, excluding that the failure to conduct an expert examination can fall into this category.

The Court reiterated a consolidated principle, albeit often debated: expert evidence is not "decisive" evidence in the sense intended by art. 606 c.p.p. This is because expert evidence is considered a "neutral" means of proof, the admission of which is left to the judge's discretion. It is therefore not evidence that parties can request as an unconditional right and whose failure to be admitted can automatically invalidate the proceedings to the point of justifying an appeal to the Supreme Court for a defect in reasoning or violation of law.

The failure to conduct an expert examination cannot constitute a ground for appeal to the Supreme Court, pursuant to art. 606, paragraph 1, letter d), of the Code of Criminal Procedure, as it does not fall within the concept of decisive evidence, being a "neutral" means of proof, left to the judge's discretion and, therefore, outside the parties' control pursuant to art. 495, paragraph 2, of the Code of Criminal Procedure, which refers exclusively to exculpatory evidence having a decisive nature.

This maxim of the Court of Cassation is illuminating. The key concept is that expert evidence, while a fundamental tool for establishing facts, is not "decisive" evidence in the sense that its omission is in itself sufficient to invalidate the decision. Its nature as a "neutral means of proof" means that it is not inherently in favor of or against the prosecution or the defense, but serves to provide the judge with technical elements for their evaluation. Consequently, its admission or not falls within the judge's full discretion, who decides whether the technical knowledge necessary for the decision requires the assistance of an expert.

Furthermore, the reference to Article 495, paragraph 2, of the c.p.p. is crucial. This rule establishes that the judge may deny the admission of "superfluous or irrelevant" evidence, but above all that exculpatory evidence "has a decisive nature" if it can lead to the acquittal of the defendant. Judgment No. 9455/2025 emphasizes that the provision of art. 495 c.p.p. refers exclusively to exculpatory evidence with a decisive nature, while expert evidence, by its nature, is not automatically exculpatory evidence and its "decisiveness" is not presumed but must be assessed by the judge within the overall context of the evidence.

Practical Implications for the Defense and the Judge

The ruling has important practical implications. For the defense, it means that procedural strategy cannot be based on the expectation that the failure to obtain expert evidence can automatically open the doors to the Supreme Court. It is essential to:

• Request expert evidence during the investigative phase: The request must be substantiated, highlighting the technical necessity and the judge's inability to resolve the issue without the assistance of an expert.
• Contest a reasoned denial: If the judge denies expert evidence, the defense must contest this denial with solid arguments, demonstrating that the technical issue is essential and cannot be resolved otherwise.
• Do not confuse expert evidence with other evidence: Expert evidence has its own specificity and should not be equated with exculpatory evidence in the strict sense of art. 495 c.p.p. regarding decisiveness.

For the judge, the judgment reiterates broad discretion in assessing the admission of expert evidence, but at the same time binds them to robust reasoning in case of denial. The denial must not be arbitrary but must be based on the conviction that the elements already acquired or the judge's own knowledge are sufficient for the decision, or that the requested expert evidence is superfluous or irrelevant.

Conclusions: Legal Certainty and the Role of the Judge

Judgment No. 9455/2025 of the Court of Cassation helps to more precisely delineate the boundaries of criminal appeals, reinforcing the principle of the judge's discretion regarding the admission of expert evidence. This ruling does not diminish the importance of technical assessment but clarifies its systematic placement within criminal proceedings, distinguishing it from exculpatory evidence that enjoys a stricter "decisive" regime for the purposes of appeal. Fully understanding these nuances is essential to ensure effective defense and to ensure that proceedings are conducted in compliance with procedural guarantees, contributing to legal certainty in a complex area such as criminal law.