Experts should reveal contradictory evidence
In the recent case of R -v- Lorraine Harris & Others (2005) EWCA Crim 1980 Lord Justice Gage was invited by counsel for the Crown to give guidance in relation to expert evidence where the evidence was considered frontier evidence and the significant failure within the criminal justice system to control and manage expert evidence. Counsel argued that there must be a change in approach. The Court of Appeal, however, took the view that, regardless of whether or not the criminal justice system had failed to control and manage expert evidence, they were reluctant to give any new guidance on expert evidence arising from the facts in these particular cases.
Gage LJ took the view that developments in scientific thinking and techniques should not be kept from the court. He considered this to have been demonstrated amply by recent cases involving new techniques such as facial mapping. He went on to express the view that this openness should be so even in cases where scientific thinking was at such an early stage that it could amount to no more than a hypothesis. Obviously, it would be imperative that the true hypothetical nature of the expert’s evidence be frankly indicated to the court.
Using the reasoning of Wall J in the case of Re AB (Child Abuse Expert Witnesses) (1995) 1 FLR 181 the current thinking of the Court of Appeal suggests that expert evidence in developing or controversial fields should have its place in court and ought not to be discouraged. However, the expert must be frank and open about the scientific status of such evidence and should reveal any material that might be contradictory. There can never be, said the court, a single test to provide a threshold for admissibility in all cases. It is up to the judge in each case to decide whether expert evidence should be admitted.
Ever have a case where you presented a report with exculpatory evidence, and you were asked to "adjust" the results?