The Admissibility of Expert Evidence in Criminal Proceedings in England and Wales

Abstract

There is no systematic deterioration in the ability of law to make sound judgments in criminal cases where scientific opinion evidence has important bearing on matters, even if doubt on its integrity has been cast over recent egregious errors. There are limitations on the capacity of science to depict the absolute truth and its conclusions always must be regarded as provisional. Law is not always aware of this. Science is not a privileged source of knowledge. It is socially constructed. Empirical studies attest high precision and objectivity in their findings but the design of studies affects the reliability of conclusions. Gatekeeper functions and rules of evidence would diminish pragmatism, flexibility and judicial discretion in court, notwithstanding that it would protect the jury from misleading evidence in some cases. If the proposal is a reaction to recent mishaps over convictions, it might be superfluous because law has not become incompetent and can continue to resolve matters using legal reasoning and the experience of judges. For judges to have to learn science would be arduous. Also, it would be unbeneficial because more would be gained by appreciation of the philosophy and sociology of science and the sociology of knowledge. Reference manuals in science are well constructed but substantial. Though training for judges in the USA has been well-received, I contend that this is inappropriate. I argue for retention of part of Option 3 of the proposal that retains experts who can form a consensus over scientific evidence and present the judge with an opinion on its accuracy. The judge can then consider this in deciding its admissibility. This eliminates the ‘deference test’ and makes the ‘panel’ merely advisory. Much of the risk of repeating recent errors can be reduced by adopting better procedures. Expert opinion witnesses should be reminded of their duty to the court. A proposal has been located in the literature that would change the role of expert witnesses to ‘auxiliary forensic professionals’ who would not be immune from civil liability. Professional bodies have instituted procedures to investigate some forms of non-accidental deaths in children. Multiplication of such protocols will relieve law of some of the burden of decision-making in this and other ‘grey areas’.