Exclusion of Evidence under Section 78 of the Police and Criminal Evidence Act: Practice and Principles

Section 78 of PACE gives the courts a discretion to exclude from a criminal trial evidence which has been obtained unfairly. The section has resulted in much case law. This article is an attempt to analyse the principles which the courts use to decide whether or not to exercise the discretion to exclude. It starts by examining the decisions of the appellate courts in order to try to identify the factors which the judges regard as relevant to this discretion. Secondly, it examines the possible policies which might underlie a discretion to exclude. It then attempts to match the practice to the policies, and concludes that ‘fairness as fair play’ is the dominant policy currently being used. The conclusion considers how the changes in the rights of the suspect (in particular the right to remain silent) introduced by the Criminal Justice and Public Order Act 1994 are likely to impact on the operation of s 78.