The Admissibility of Communications Metadata as Evidence

This chapter examines the conditions under which communications metadata can be used as evidence in criminal trials while safeguarding fairness. It reviews ECtHR and CJEU case law on admissibility and Member States’ rules on evidentiary sanctions. The analysis shows that European jurisprudence sets low barriers to the use of metadata, even when obtained through unlawful retention or unregulated surveillance, as fairness tests often neutralise privacy and data protection violations. Similarly, national systems face limits in enforcing exclusionary rules, particularly given the narrow scope of metadata-specific safeguards and the structure of mixed-inquisitorial proceedings, which risk unfair impacts on defendants.