Ações encobertas
: da sua admissibilidade como meio oculto de investigação à valoração da prova obtida

  • Mónica Alexandra Marques Costa (Student)

Student thesis: Master's Thesis


The figure of the undercover agent is characterized, as a occult method of investigation, as being one of the most effective ways to combat the most complex forms of crime that has evolved with the times. The undercover actions are designed at carrying out one or several acts of investigation and discovery that end up in obtaining evidence about to the crime and its perpetrators. Alongside this partly dubious reality, due to its occult nature, questions are raised regarding its admissibility under the regime of prohibition of evidence provided for in article 126.º of the Code of Criminal Procedure. Having approached this elementary point and based on the principle of its admissibility - keeping in mind the weaknesses and limits underlying this method of criminal investigation - the purpose of this work is, according to the legal regime of the undercover actions, to determine the value of the evidence obtained by the agent in the action in which he intervened and how he can produce it in the criminal process. The agent who has acted in a undercover action under a fictitious identity according to the terms of the law, may in line with the verification of certain premises, make statements at the trial audience under conditions of anonymity. This measure to protect the undercover agent, as a witness, in the criminal process will be applied in compliance with the Witness Protection Law, furthermore to providing the procedures for applying the measure, prescribe albeit implicitly, the proportion that the witness's testimony agent can assume in relation to the reasoning and decision-making that falls to the Judge at the trial audience. In this segment, we aim to outline the particular evidential value of the testimony provided by the agent in question, considering possible limitations and requirements that this subject may present in relation to the general regime of free assessment of the evidence.
Date of Award4 Nov 2020
Original languagePortuguese
Awarding Institution
  • Universidade Católica Portuguesa
SupervisorJosé Damião da Cunha (Supervisor)


  • Ações encobertas
  • Agente infiltrado
  • Método oculto de investigação
  • Métodos proibidos de prova
  • Prova obtida
  • Declarações anónimas
  • Valoração da prova


  • Mestrado em Direito

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