Should forensic scientists offer non-scientific evidence?

Having just completed a report on a case where DNA transfer was one issue and re-reading Christophe Champod’s review in Forensic Genetics (Champod 2013) brings to mind an additional point in the “experience v scholarship” debate; the ethical responsibility/duty of a forensic scientist acting as an expert witness.

Courts, particularly in England and Wales, have made it clear through a number of judgements (R v Reed, Reed & Garmson 2010) (R v Weller 2010) that opinions supported only by the experience of the expert witness are admissible and will be given weight (twas ever thus).

Numerous authorities (Champod 2013) have also made it clear that expert opinion based solely on experience puts justice at risk.

Even if courts will hear such evidence it is right for scientists to offer non-scientific evidence? In the absence of relevant research and scholarship surely the only answer the scientist can give is that science cannot help.

Furthermore, in the absence of relevant research and scholarship, is the forensic scientist better placed than the fact-finder to evaluate propositions?

Given the plethora of codes of conduct/practice and regulatory frameworks that now exist it surprises me that the questionably ethical practice of offering fact-finders non-scientific evidence has not been identified as malpractice and sanctions put in place.

Champod, Christophe. “DNA transfer: informed judgment or mere guesswork?” Frontiers in Genetics, 2013: 1-3.

R v Reed & Reed & Garmson. Crim 2698 (EWCA, 2010).

R v Weller. Crim 1085 (EWCA, 2010).