The paper is dedicated to ne bis in idem principle, which is a fundamental human right safeguarded by Protocol No. 7 to the European Convention for the Protection of Human Rights and Fundamental Freedoms. This principle is sometimes also referred to as double jeopardy.The principle implies that no one shall be liable to be tried or punished again in criminal proceedings under the jurisdiction of the same State for an offence for which s/he has already been finally convicted or acquitted (internal ne bis in idem principle), and that in some other State or before the International Court (ne bis in idem principle in respect of the relations between the states or the State and the International Court) the procedure may not be conducted if the person has already been sentenced or acquitted. The identity of the indictable act (idem), the other component of this principle, is more complex and more difficult to be determined than the first one (ne bis).The objective of this principle is to secure the legal certainty of citizens who must be liberated of uncertainty or fear that they would be tried again for the same criminal offence that has already been decided by a final and binding decision. This principle is specific for the accusative and modern system of criminal procedure but not for the investigative criminal procedure, where the possibility for the bindingly finalised criminal procedure to be repeated on the basis of same evidence and regarding the same criminal issue existed. In its legal nature, a circumstance that the proceedings are pending on the same criminal offence against the same accused, represents a negative procedural presumption and, therefore, an obstacle for the further course of proceedings, i.e. it represents the procedural obstacle which prevents an initiation of new criminal procedure for the same criminal case in which the final and binding condemning or acquitting judgement has been passed (exceptio rei iudicatae).The right not to be liable to be tried or punished again for an offence for which s/he has already been finally convicted or acquitted is provided for, primarily, by the International Documents (Article 14, paragraph 7 of the International Covenant on Civil and Political Rights and Article 4 of Protocol No. 7 to the European Convention for the Protection of Human Rights and Fundamental Freedoms). The International framework has also been given to ne bis in idem principle through three Conventions adopted by the Council of Europe and those are the European Convention on Extradition and Additional Protocols thereto, the European Convention on the Transfer of Proceedings in Criminal Matters, and the European Convention on the International Validity of Criminal Judgments.Ne bis in idem principle is traditionally associated with the right to a fair trial under Article 6 of the European Convention for the Protection of Human Rights and Fundamental Freedoms. Likewise, no derogation from Article 4 of Protocol No. 7 shall be made under Article 15 of the Convention at the time of war or other state of emergency which is threatening the survival of the nation (Article 4, paragraph 3 of Protocol No. 7). Thereby it is categorised as the irrevocable conventional right together with the right to life, prohibition of torture, prohibition of slavery, and the legality principle. Similarly, ne bis in idem principle does not apply in the case of the renewed trials by the International criminal courts where the first trial was conducted in some State, while the principle is applicable in the reversed situation. The International Criminal Tribunal for Former Yugoslavia could have conducted a trial even if a person had already been adjudicated in some State, in the cases provided for by its Statute and in the interest of justice.
Significance of the European Convention for the Protection of Human Rights and Fundamental Freedoms in the implementation of the constitutional right to a fair trial in European and Ukrainian states: problems of law enforcement
