Secret witness in criminal procedure law

The main purpose of criminal procedure is to reach the material truth in the presence of those who have the right to be present at the hearing, without hiding the identity of the person who will testify, and by meeting all the conditions required by universal law principles, especially the defendant's right to a fair trial. Evidence has an important place in reaching the material truth in criminal procedure. Witness statements are also among the evidence needed to revive a past event that is the subject of trial and to shed light on its dark aspects. People who will testify must accurately convey the information they have acquired through their sense organs to the reasoning. It is a known fact that in trials regarding some crimes with severe penalties, witnesses are confronted with pressure, violence and intimidation methods by the defendants. This reality causes people who will testify to give up their testimony or not to convey what they know correctly to the trial. The occasional danger to witnesses in the process of reaching the material truth has led to the introduction of the exceptional institution of secret testimony into our legal system. Especially in crimes committed within the scope of an organizational activity, there is a need for secret testimony. Members of the organization, who want to continue their existence and are very professional in leaving no trace behind, use all kinds of pressure, violence and intimidation methods to prevent witness statements from being included in the trial. In order to preserve the continuity and complex structure of organizations, witnesses should not convey what they know to the trial. For this reason, members of the organization want to prevent witnesses from making statements. In order for the witness to convey what he knows to the judicial authorities in a healthy manner, he and his relatives must be protected against possible dangers. The institution of secret testimony is a measure that emerged with the idea that by preventing the identity of the witness from being known, the most effective protection against possible dangers to the witness and their relatives will be provided. The secret witness is heard in a different way than normal testimony, and it violates some defense rights such as the directness of the trial, the publicity of the hearings, and the hearing of witnesses on the basis of equality. For this reason: if the protection of endangered witnesses can be ensured by another method or if the use of secret witness measures is not of indispensable importance for the prosecution, this exceptional institution should not be resorted to. While secret testimony serves to protect witnesses, it also interferes with the defendant's fair trial and defense rights. In our study, the subjects of evidence and proof, witnesses and secret witnesses in criminal procedure will be discussed. Subsequently, the importance of testimony in terms of criminal procedure, the dangers to the witness and the characteristics of the secret testimony measure will be examined and the issues in which cases, under what conditions and in terms of which crimes this institution can be used will be discussed. Finally, a general evaluation of the secret testimony measure will be made in terms of criminal procedure principles, and the approach of the ECHR and the Constitutional Court regarding secret testimony and the criteria sought will be explained. Keywords: Witness, secret witness, organized crimes, protection of witnesses, right to a fair trial.