This book endeavours to objectively address the power of suggestion and the implantation of false memories in individuals and their effects in criminal proceedings, especially during the criminal interrogation of the accused and the hearing of victims and witnesses of criminal offences. We analyse the main flaws that may arise in the production of testimonial evidence, as it is the most widely used means of proof in Brazilian criminal proceedings. There is a brief analysis of the process of memory formation, as well as the interferences that may arise in this process. In this work, we also mention the consequences that may arise from an unsuccessful enquiry, in the investigative phase and in the procedural phase itself, by the police authority, judges and members of the Public Prosecutor's Office, and the obstacles that may arise during the investigation of the real truth of the facts and, consequently, for the realisation of justice.