TENSOR: Policy recommendations on biometric data use and sharing in EU law enforcement

Executive SummaryThe growing use of biometric technologies by European law enforcement agencies has changed how investigations unfold and how data moves across borders. These tools can make police work faster and more precise, but they also raise ethical and legal questions. This paper examines these gaps through the experience of the TENSOR project, which develops tools to extract biometric evidence and enable secure cross-border data exchange. The paper draws from pilot activities, questionnaires, and interviews with law enforcement authorities, the paper identifies both progress and persistent challenges. It shows that technology alone cannot ensure justice without stronger legal clarity, operational consistency, and ethical safeguards. From this effort two conclusions emerge. First, Member States need to align national laws and infrastructures to achieve real interoperability. Second, technological development must remain grounded in the principles of legality, accountability, and respect for fundamental rights. A harmonious European approach can ensure that innovation strengthens public safety without eroding public trust. To support this balance, five policy actions are proposed. An EU certification scheme for biometric systems would guarantee that technologies meet minimum standards for accuracy, security, and fairness. Standardized frameworks for data sharing would give LEAs common templates and infrastructures that reduce fragmentation and speed up cooperation. Mandatory training on AI ethics and fundamental rights would help officers understand the risks and responsibilities that come with digital tools. Inclusion of safeguards for human oversight in national legislation and procedures. Finally, a Biometric Use Forum would create space for dialogue among law enforcement, regulators, and civil society to anticipate risks and share good practices. These measures reinforce the EU’s robust legal framework by turning its principles into concrete action. Certification, standardisation, training, oversight, and open dialogue create the conditions for ethical and interoperable use of biometric systems. In doing so, they help align national practices with Europe’s broader vision of secure, lawful, and rights-respecting innovation.