Admissible Evidence

Abstract

Abstract This chapter addresses the core evidentiary idea of ‘admissibility’. Exclusionary rules are the hallmark of common law approaches to regulating evidence, but they do not—as is sometimes asserted or assumed—exhaust the disciplinary domain of evidence law. The first hurdle to admissibility is relevancy; which is assessed by extra-legal considerations of logic and common sense. Irrelevant evidence is always inadmissible. Exclusionary doctrines target particular categories of relevant but ‘suspect’ evidence—information which may be unsuitable for inclusion in criminal trials on epistemic and/or normative grounds. However, exclusionary rules are typically subject to a further normative layer of inclusionary exceptions. Admissibility structures are presented in a simple flowchart. Evidence is also routinely categorized according to whether it is direct, circumstantial, real, collateral, or testimonial. Additional sources of information in litigation include formal proofs, agreed evidence, views and demonstrations, and miscellaneous informal sources of knowledge and observations. All types and sources of information relied on criminal trials should be tested against normative standards of procedural justice (including human rights and fair trial principles).