Since the European Union acquired legislative competence in criminal law and criminal procedure law, various scientific and political debates have been emerged on the impact of the Europeanization of criminal law. While some of these debates emerge as to how do traditional European Union law debates such as separation of powers, respect for the general principles of European Union law, protection of fundamental rights take place in the context of criminal law; another part of concerns have focussed on the effects of the Europeanization of criminal law to the basic principles and doctrines of criminal law, such as the principle of legality, the principle of individual responsibility, guilt and punishment. Instead of dwelling on these matters, this article focuses on the Europeanization of the criminal law systems of the Candidate Member States and the twinning projects financed by the the European Union grant for external aid programs, which play an important role in this process. In this context, one of the twinning projects carried out by Turkey in the field of "justice and home affairs", "Strengthening Victim Rights in the Criminal Justice System" has been chosen as an example. The goal with this project carried out under the partnership of the Kingdom of Spain for the period 2017-2019 was to establish “an appropriate, effective and sustainable victim support model” in the Turkish Criminal justice system.