Expert evidence, justified and independent or tailored to fit?

With more and more scientific or “expert evidence” being used in trials on a daily basis and the level of convicted prisoners maintaining their innocence it is necessary to ask what if any benefit is being gained in terms of a fair trial.

If we could be certain that the ‘evidence’ provided by these witnesses was restricted to that which is categorically beyond question and free from speculation or subjectivity then their input and hence assistance to a jury would be clear. That is of course if the information they provide is communicated in a manner with which it is reasonable to expect any member of the public to understand. The latter of which forms part of a joint responsibility with legal representatives in court, who, if they are not satisfied that the evidence is presented accordingly should insist that it be clarified.

To give some idea of the misrepresentative ‘expert testimony’ routinely banded about in British courts, we need only to look at the statistics commonly offered in terms of DNA profiles. It will often be stated that the possibility that a profile matches someone other than the person pinpointed by this experts findings is in the region of 1 in a billion. Any jury would be forgiven for thinking this is conclusive and that any other explanation is simply too far fetched. However we only need to look at the relatively small Arizona DNA database to see a very different reality (see this page for reference – http://www.oldbury.chat.ru/dnapr.htmwritten by Paul Nutteing).  There were only around 65,000 profiles,  of which 1 in every 228 matched at 9 points, 1 in 1,489 matched at 10 (the standard currently accepted in Britain), 1 in 16,374 matched at 11 points, and 1 in 32,747 matched at 12 points. Obviously therefore, as the database size increases so does the number of false matches meaning that if you double the database, instead of 1 in 1,489 false matches at 10 points, there is likely to be 1 in 1,489 treble or quadruple false matches. This means that even in a small database of 65,000 could be 43.65 false matches. How then can anyone stand up in court with a straight face and quote 1 in billion? In fact, if you are of typical white male orientation and have no outside influences in the last three generations, there is a 1 in 120 chance of a false match with another typical white male on the DNA database. Scary? I’d say and hardly categorically beyond question.

As a demonstration of how damaging these “matches” can be, we need only look at the case of Raymond Easton – http://archive.thisiswiltshire.co.uk/2000/8/15/238098.html- which thankfully forced the change from 6 point matches being accepted to 10 points which is better but not enough. The 49 year old Parkinson sufferer was arrested and charged following a burglary some 200 miles away from where he lived following a ‘DNA match’. Mr Easton couldn’t walk more than 10 yards unassisted, nor could he dress or bath himself. Being a 6 point match he was told the chances of the profile belonging to anyone else was 1 in 37 million. Mr Easton, agreed to a second test which also matched so it is clear that this was no mistake during labelling etc. Despite his medical condition and the need for 24 hour care, his ordeal was to last 4 months until the crown finally accepted it could not possibly have been him. This is not a one off case either. A 70 year old disabled man was also accused of a burglary between 100 and 200 miles away following a DNA ‘match’. He was remanded in custody but thanks to his defence agent was later released when it transpired there was a second match on the database to a person with a string of burglary convictions who just happened to live nearby the crime scene!

The fact is, though the chances of false matches are reduced by the current 10 point standard, they are not eliminated by any stretch of the imagination. If the chances of a mismatch were quoted at 1 in 1 million it would still be misleading.

We also must consider the financial rewards available to expert witnesses and where these rewards come from. For example, according to one technician in telecommunications analysis, 75% of payments are made by the crown. It therefore follows it is in the interests of such technicians to keep the crown satisfied to secure future income. Perhaps that’s why one ‘expert’ stated, “I am not paid to look at other propositions.  The people who pay me would not be happy if we go off and do things they haven’t asked us to do.” In other words, ‘I did not point out anything which conflicted with their suspicions unless I was specifically asked to confirm it.’

Is this really the type of ‘expert testimony’ we want in our ‘fair and impartial’ courts? I think not. I think we’d all like to see just how many false matches there are currently on the DNA database and assess how best to safeguard the innocent while at the same time provide a tool to convict the guilty. A tool to convict the guilty should at no time be equivalent to a tool to convict any random person without proper consideration of its evidential worth.