… anyone attending the Forensic Society conference in Edinburgh last week was left in no doubt that there are serious concerns about the use and admissibility of expert scientific evidence in the Scottish courts. The main problem identified was the lack of a clear rule on reliability.
The desire to ensure that only reliable science is admissible is obvious – but how can you tell it is reliable, and whose job is it to find out? It is also vital that it is communicated effectively to the fact finder, whether that is a judge or jury. Miscarriages of justice have occurred due to unreliable science, unreliable interpretation of science and unreliable practices of “experts”.
Our history and the problems faced in other jurisdictions tell us that Scotland is not uniquely protected from bad science or dubious experts. We are, though, unique in the common law world in failing to review our systems to proof them against weak practice.
While the fingerprint inquiry set up in the wake of the Shirley McKie case was an important start, it had a very specific remit. That degree of investigation and rigorous analysis is what is required for the practices surrounding the rules for the collection, management and admissibility of forensic science.
The Lord Advocate, Frank Mulholland QC, told the conference: “Expert evidence used to be rare in criminal trials. Now it is the norm.” It is his aim, he said, to avoid miscarriages of justice arising from errors in expert evidence. (...)
Unlike other countries, Scottish judges have no role to act as gatekeepers to prevent unreliable evidence being admitted. We let the adversarial process, ie the opposing parties, choose the experts and determine what is admitted. But lawyers rarely have a higher educational background in science and some, we heard, are anxious about examining witnesses in areas of expertise with which they are unfamiliar. That serves no-one well.