Criminal Procedure as a Leading Branch of Law in Relation to the International Legal Systems of the EU and the USA

Abstract. Criminal procedure is one of the leading branches of law that plays a crucial role in maintaining law and order, justice, and human rights. In the context of globalization and the integration of international legal systems, particularly those of the European Union (EU) and the United States of America (USA), criminal procedure takes on special significance. Comparing the criminal procedures of Ukraine, the EU, and the USA allows for the identification of common features, differences, and best practices that can be adapted to enhance the effectiveness of national justice systems. The primary areas of comparison between Ukraine's criminal procedure and the international legal systems of the EU and the USA include issues related to human rights protection, transparency of judicial processes, equality of parties, and access to justice. Studying the approaches of these legal systems helps to determine how international standards can be implemented at the national level to improve legal protection for citizens. The EU is characterized by a high level of integration in criminal legislation among member states, which ensures uniform legal approaches and streamlined procedures within the Union. An important aspect of the European criminal procedure is the emphasis on protecting human rights and freedoms, notably through the European Convention on Human Rights. In the USA, criminal procedure is marked by a complex structure due to the federal system, where each state has its own judicial system. However, a key principle remains adherence to the US Constitution and the rulings of the Supreme Court. Particular attention is given to procedural guarantees for the accused, including the right to a fair trial, which is a fundamental principle of the American legal system. Analyzing the relationship between the criminal procedures of Ukraine, the EU, and the USA provides a deeper understanding of legal mechanisms and helps develop recommendations for adapting successful institutions and practices to Ukrainian legislation. Keywords: criminal procedure; international law; European Union; USA; human rights; legal system; judicial system; justice; comparative law; legal standard.