One of the first evidential rules taught to students of criminal evidence is the requirement that all evidence in a criminal trial must be relevant before it can be admitted. Relevance has been described as ‘possibly the most basic concept in the law of evidence’ and works quietly and (supposedly) uncontroversially to regulate the admission of evidence. Its importance should not be underestimated though, it applies universally to all pieces of evidence and, if established, means evidence is prima facie admissible and may be put before a jury. Given this central role of relevance in criminal proceedings, it is important that we understand what relevance is, what it means, and how decisions on evidential relevance are made in practice.
