‘A new and more rigorous approach’ to expert evidence in England and Wales?

Abstract

An amendment to the Criminal Practice Direction issued by the Lord Chief Justice of England and Wales lays down guidance for judges to follow in determining whether expert evidence is ‘sufficiently reliable to be admitted’. Although the guidelines are based on those proposed by the Law Commission in 2011, they do not include a definition of ‘sufficiently reliable’, such as would have been provided by the Law Commission’s Draft Bill, which the government declined to introduce. A criterion of ‘sufficient reliability’ must therefore be found within the common law. This article argues that ‘sufficient reliability’ is an aspect of ‘helpfulness’ and reflects the principle that experts should provide the jury with criteria with which to assess the weight of their evidence. Reliable evidence, in short, is evidence that provides the jury with sound reasons for relying on it. This criterion could be as rigorous as that proposed by the Law Commission, and possibly more so.

Expert Testimony, Law and Epistemic Authority

“…The guidelines for judges have made their way into law through a Practice Direction issued by the Lord Chief Justice, 62 but without the statutory test that they were designed to accompany. I have argued elsewhere 63 that the gap left by the failure to legislate can be filled by developing the embryonic common-law test of whether evidence is 'sufficiently reliable to be admitted' in a way that is faithful to the Davie principle: evidence is 'sufficiently reliable' if it provides the jury with a sufficient basis to decide how far they can rely on it. The question of what degree of weight a jury could rationally accord the evidence needs to be considered not only in relation to the admissibility of the evidence but also in relation to whether the evidence against a defendant, taken as a whole, amounts to a case to answer, and in considering how to advise the jury about the evaluation of the evidence.…”

Communication, forensic science, and the law

“…Indeed, scientific evidence in the court is considered expert evidence and therefore the scientist is an expert witness. As expert witnesses, forensic scientists can give opinion evidence in court on a subject on which they have knowledge and expertise above that of the layperson, in this case, the court since the lay audience in the court is not expected to have the same level of knowledge as they do (Ward, 2015). The forensic scientist, therefore, plays an important role in communicating their methods and findings to the finders of fact, the jury, allowing them to understand the evidence that is placed before them, enabling them to come to a decision.…”

Experts and pretenders: Examining possible responses to misconduct by experts in criminal trials in England and Wales

“…As Ward notes (2015: 239), the sanction for non-compliance could be exclusion of the expert’s evidence as a whole, or on specific points. In some cases, this could lead to the collapse of the case, though often another expert can be found if the issue is identified early enough.…”