When Europe made the historic decision to set aside its internal borders, the national jurisdictions of the Member States – in areas as varied as tax law, product liability, criminal or family law – changed for good. As individuals, their businesses, products, cars and families began to cross national borders, they began to move between national legal orders. While this development sought to abolish boundaries in relation to individuals and the market, it also facilitated transnational crime. Cross-border crime and the lack of borders across the EU required the development of new legal instruments, including instruments of mutual recognition, harmonisation of definitions of criminal offences, trans-European institutions, arrest and evidence warrants, and soon, an EPPO.

A European criminal justice system cannot, and should not, only exist to battle cross-border crime. The EU has transformed from a union promoting economic interests towards ‘an ever closer union among the peoples of Europe’, which shall ‘offer its citizens an area of freedom, security and justice without internal frontiers’. It is a legal order based on democracy and the Rule of Law, human dignity, solidarity and freedom. Any creation of a European criminal justice system raises questions regarding its legitimacy and purpose. Hence, European criminal law must be armed with legal principles that reflect the values of the EU, a union of the nation states built upon the Rule of Law and fundamental rights. One of these principles is the principle of legality, a doctrine deeply rooted in most national systems. While this principle already exists within the European legal order, it is still in its infancy.

THE PRINCIPLE OF LEGALITY AND THE CRIMINAL LAW

The principle of legality is a cornerstone of criminal justice systems around Europe. It is codified in international instruments, e.g. Article 7 ECHR and Article 22 of the Rome Statute of the International Criminal Court, national constitutions and criminal codes, such as Article 1 GCC, Article 16 of the Dutch Constitution. The essence of this principle is that no person can be punished for an act that is not criminalised by law, in other words, ‘there is no crime without law.