Operazioni sotto copertura dalla prospettiva della Corte Europea dei diritti dell'uomo: la sottile dicotomia tra agente sotto copertura e agente provocatore.

In recent decades, crime has become so highly sophisticated that the need to reinforce traditional investigative approaches with different innovative mechanisms – the so-called “special” investigative techniques - such as surveillance methods and undercover operations has been increasingly perceived. The latter are complicated strategic police-tactical methods whose use is allowed only for those serious crimes against which other means cannot be adopted, or in the case in which the applied methods have not yielded successful results. The engagement of undercover agents is, no doubts, the most complicated and controversial among the methods of covert operations, both in terms of law enforcement and operational meaning. Although it is typical, because it is provided for and regulated by law, numerous hermeneutical doubts on the figure of undercover agents persist despite the various rulings issued in both domestic and supranational case-law and the different regulatory interventions which have succeeded one another over time. Specifically, an issue which is worthy of discussion and revolves around the heart of this thesis concerns the problematic practical implementation of this institution and its controversial assessment as shown by the case law of the European Court of Human Rights. The Court has analysed the figure in question under the complexity of its procedural profile, with specific regard to its conformity with the principle of fair trial enshrined in Article 6 of the Convention. As a matter of fact, the admissibility of undercover agents carries considerable implications in that it intervenes into the fundamental rights of individuals and, as many have repeatedly pointed out, it seems to deviate from the basic principles of the democratic State complying with the rule of law. To put it in other words, what makes investigative techniques like undercover operations “special” does not simply lie in the fact that they are undertaken secretly, since much of police investigative work is, by its very nature, performed “undercover”, but also in the fact that they are very intrusive. In fact, while on the one hand, these instruments may be highly effective in detecting crimes, on the other, the risk of manipulating the defendant’s conduct is very likely to be caused as a result of the combination of secrecy and a significant level of intrusion. In this perspective, the European Court of Human Rights has an extensive record of judgements concerning the resort to special investigative techniques by law enforcement authorities and national security agencies. For a long time, it has been dealing with them on case-by-case basis, considering each application as if it was a unique set of facts and legal issues to be settled. Nevertheless, over the years, because of the ever-increasing number of complaints related to the admissibility of evidence gathered through the use of said techniques, the Court had to consolidate its reasoning and to lay down general principles to be applied from that moment onwards. In this connection, throughout its case-law, it has set up an elaborated system of principles that covers three main areas: the manner through which undercover operations are carried out and special techniques are used; the admissibility of the evidence gathered during the trial, and the withholding by the prosecution of confidential information that is not included in the case file.