Abstract

In recent years there has been major concern about the reliability of much forensic evidence adduced at criminal trials. Clinical forensic paediatric evidence has come under particular criticism after high-profile wrongful convictions in several common-law jurisdictions. In their aftermath, some eminent paediatric medical expert witnesses were publicly vilified, endured protracted hostile pressure-group campaigns, and were subject to severe professional regulatory discipline, sometimes unjustified. Why are paediatric forensic cases so problematic?

From a paediatric perspective, a number of issues may influence the objectivity of expert forensic opinion, including the intuitive and heuristic processes involved generally in expert clinical diagnosis, the potential influence of professional child advocacy values, the divided loyalties of clinical and forensic roles, and the risk of implicit ‘cognitive contamination’ from adverse contextual information.

Further, despite significant efforts to advance research in clinical child protection over the last 25 years, the evidence base on which expert opinions in child protection may be founded remains patchy. In some important areas the reliability of such evidence lacks a robust theoretical or empirical justification, while there is no agreed verbal scales that might promote consistency among paediatricians and related specialists in formally expressing a likelihood that a child has been abused.

While it is clear that, in some cases, there have been egregious failures by individual clinicians, the justice system cannot escape criticism. A key issue is to ensure the reliability of the evidence to be adduced. The rules governing the admissibility of forensic opinion evidence are relatively permissive in most common-law jurisdictions, especially the UK, where there is no explicit judicial gatekeeping role. This is compounded by a general lack of scientific expertise among judges and lawyers expected to assess the reliability of such evidence. The intrinsically partisan adversarial system does not provide an adequate safeguard to expose clinical and scientific uncertainties and, as many expert paediatric witnesses acknowledge, the crucible of cross-examination rarely reveals the “whole truth” as they perceive it.

Such systemic weaknesses in the justice system are rarely acknowledged.