Leveraging metadata and big data for criminal investigations: comparative perspectives from Europe, USA and China

This paper explores the evolving role of metadata and big data in criminal investigations, with a comparative analysis of legal frameworks in Europe, the United States, and China. It examines the dual potential of these data tools as instrumental in solving crimes and as sources of significant privacy risks. Particular attention is given to data retention laws, the European General Data Protection Regulation (GDPR), and the AI Act 2024, highlighting their implications for balancing privacy and investigative efficiency. The U.S. sectoral approach and China's robust yet state-focused privacy regulations are evaluated to underscore the global challenges and disparities in regulating big data. The paper critiques Italy's long metadata retention periods, in contrast with shorter durations in other EU countries, and advocates for reforms aligned with GDPR principles. Additionally, it addresses into the ethical and regulatory complexities posed by AI-driven investigative tools, including algorithmic biases and data ownership concerns. The study emphasizes the need for international regulatory harmonization to ensure that advancements in big data and AI uphold privacy and human rights while enhancing justice.