Artificial Intelligence in Criminal Justice: Balancing Technological Innovation and Personal Data Protection Rights – A Comparative Legal Study between the European Union and Vietnam

Background: The rapid development of Artificial Intelligence has profoundly transformed various aspects of social life, including the criminal justice system. In criminal proceedings, the collection and processing of biometric, behavioral, and emotional data may threaten the right to privacy, the presumption of innocence, and the right to a fair trial. This study examines the intersection between technological innovation and personal data protection in criminal justice through a comparative legal analysis of the European Union and Vietnam. By analyzing the EU’s GDPR, Law Enforcement Directive, and AI Act 2024 alongside Vietnam’s legal framework, the paper identifies key areas of convergence, divergence, and regulatory gaps. Methods: The study employs comparative legal analysis, combined with a human rights–based approach, to clarify the relationship between technological innovation and the right to personal data protection in criminal justice. The sources of reference include the legal frameworks of the European Union and Vietnam, case law and reports from bodies of EU and United Nations. Results and Conclusions: The study aims to establish fundamental legal principles that balance technological innovation with the protection of the right to personal data in criminal justice—an approach that has received limited attention in Vietnam. Based on this foundation, it proposes legal reforms toward a framework of “human rights–oriented digital justice”, ensuring that the digitalization and application of AI in the justice system not only enhance operational efficiency but also strengthen the rule of law and protect people.