Traditionally, criminal law and adjudication had been regarded as the exclusive competence of European nation-states. This view began to change with the establishment of the Council of Europe and the European Union. Within the CoE, the main instruments exercising influence over the national criminal justice systems are the European Convention of Human Rights and the case law of the European Court of Human Rights (the ECHR system). Although the implementation of the standards generated by the ECHR system has been imperfect (Spronken, 2012), possibly not one national system of criminal procedure of the CoE Contracting States has been entirely immune from their influence (Keller and Stone-Sweet, 2008; Motoc and Ziemele, 2016).