IT is hard to argue with Lord Clarke's key conclusion in overturning the convictions of Kimberley Hainey for the murder of her son Declan.

Lord Clarke said that he and the other two appeal judges believed it was of the "utmost importance" expert witnesses should be relevantly qualified, competent and experienced. This is clearly true.

In the case of Sue Black, the widely- respected forensic anthropologist involved in that case, the word relevantly is significant. The judges said she had been allowed to speak to areas beyond her discipline, to the extent that they felt justified in describing her as an "obvious quack doctor".

One solution, according to their written findings, could be to look at procedures used in other jurisdictions, which allow for expert evidence and witnesses to be challenged before they are heard in court.

This can already take place under Scottish law, but does not happen routinely.

There are arguments against change. In America, such pre-trial deliberations can go on for months or even years, and can mean that more cases fail to reach court at all. Would we be prepared to accept this?

It could also be dangerous to take these judgments out of the hands of juries. If we establish a principle that juries cannot be trusted to make these decisions for themselves, what else should we predetermine for them? Would such deliberations be in public so that justice can be seen to be done?

Yet it can clearly be difficult for juries to determine how reliable an expert is, even more so if they have to determine whether such expertise covers the precise testimony they are giving.

Meanwhile, it could be more efficient to deal with disputes about what evidence is reliable, helpful or admissable before a case comes to trial.

If defence and prosecution can agree on areas which are not contested, time can be saved or focused on the issues which are critical to ensuring a just outcome. Judges could be better equipped to prevent witnesses from straying into areas beyond their professional limits.

Last month the Forensic Science Society held an event calling for a change to the use of expert evidence in Scottish trials, pointing out that flawed expert evidence can lead to miscarriages of justice, with huge costs in financial and human terms. The findings were forwarded to the Scottish Parliament's justice committee and to Kenny MacAskill.

Leaving aside the unhappy circumstances of the Hainey trial, it woud be beneficial if the Justice Secretary were to listen to them, and to the findings of the appeal judges.

Lord Clarke's point is that in England and Wales it is required that medical evidence led and relied on in a trial should be considered at a pre-trial hearing. This is already possible in Scotland, but there are strong reasons for a public debate about whether it should be mandatory here too.