Expert evidence: can we learn from others?

By Anna Sandiford 17/12/2013


One of the hardest things to do in life seems to be to learn from the mistakes of others.  For example, when learning to drive (“mirror, signal, manoeuvre” has been devised for good reason, not, as young male relatives seems to think, just so older people can tell younger people what to do and then say “told you so”).

Allowing people to give evidence in court as experts is another example where we can learn from others.  England and Wales recognised a long time ago that expert witness evidence and experts themselves were far from perfect: think back to the days of the West Midlands Police Flying Squad and the Birmingham Six and the development of the Forensic Science Service so as to separate forensic scientists from the Police.  There have still been problem cases since then such as R v Dallagher (earprint evidence) and problem experts.

The Ministry of Justice in England and Wales has recently published its response to the Law Commission’s report “Expert evidence in criminal proceedings in England and Wales”.  Of the 22 recommendations made by the people who know what it is like to do the job on the ground (i.e. those who provided comments to the Law Commission), the Ministry has accepted five – for a government department that is probably not a bad acceptance rate, but what have they accepted?

Recommendation 8. “We recommend that primary legislation should provide that expert evidence is admissible in criminal proceedings only if:

(1) the court is likely to require the help of an expert witness; and
(2) it is proved on the balance of probabilities that the individual claiming expertise is qualified to give such evidence.”
Recommendation 9. “We also recommend that this legislation should provide that expert evidence is inadmissible if there is a significant risk that the expert has not complied with, or will not comply with, his or her duty to provide objective and unbiased evidence, unless the court is nevertheless satisfied that it is in the interests of justice to admit the evidence.”

Pretty basic stuff you’d think but only now is this being formalised in legislation in the UK.  Does NZ need something as explicit as this?  I think so, but the perception in NZ seems to be that there is case law to cover such concerns and that expert evidence is generally of a sufficient standard; we are apparently a pretty good self-regulating bunch. 

Personally I think that as a minimum the NZ High Court Code of Conduct for Expert Witnesses should be compulsory in the criminal court as it is in the civil arena – I see so many reports that don’t meet the standards but it’s not compulsory so is hit-and-miss if there is a challenge in court.

But what would I know?  I’m just an expert witness with 15 years’ experience in the criminal court systems of three jurisdictions and a smattering of knowledge about international standards.