The wrong expert can break a case, but litigators can avoid the pitfalls if they have the discipline to choose carefully, says Henry Bermingham




The case of Gene Morrison - the bogus forensic psychologist who was recently jailed for five years at a Manchester Crown Court - highlights the importance of choosing expert witnesses carefully. Convicted on 20 charges, Morrison was described by the judge as an 'inveterate and compulsive liar'. His case follows a number of worrying appeals concerning expert evidence.



In Woolley v Essex County Council (2006), the expert reached an 'obvious mistake' in setting out a conclusion at odds with the rest of his report. Furthermore, in Stallwood v David Adamson (2006), a change of mind at a joint meeting of experts by the claimant's expert threatened the claimant's entire medical case. And these issues are minor compared to the discredited evidence against the wrongly convicted solicitor Sally Clark and the consequences of it.



So how should lawyers avoid the pitfalls of choosing the wrong expert? While there are never guarantees, the answer is due diligence, integrity and thought.



Every litigation practice has a database of experts it has used in the past. Start there, and look for an expert whom colleagues have used and trust. Consult directories for a steer on an expert who works in an unusual field. Investigate a proposed expert and always obtain his CV. Ask for references if any questions emerge about the expert. In personal injury cases it is advisable to check the division of claimant and defendant work carried out by the expert.



A litigation lawyer once said: 'Our business is the truth.' While idealistic, that sentiment offers some protection from selecting the wrong expert. In the pre-Woolf reform days, each side retained its own 'hired gun'. The claimant would find an expert who was prepared to say an injury was disabling and permanent. The defendant could be relied on to roll out a sceptical expert to counter that view.



Sadly, on both sides, there are still solicitors and experts who think it is appropriate to provide or rely on such evidence. They may get away with it for some time, but eventually the day of reckoning will come and the hired gun will fail to go off at trial. That can make for expensive failures.



Besides trials, there are at least three other occasions when the wrong expert can destroy a case. The first is on direct questioning from the opposing solicitors. The second is at the joint meeting, when his opposite number advances detailed counter arguments. Finally, as the court door approaches, an expert can become nervous about cross-examination and may let down everyone at the final conference with counsel. Basic checks and balances should help to avoid this.



In the ordinary course of events, avoiding the hired gun is easy - due diligence will steer you clear of him. However, no system is perfect, so review an expert's evidence carefully and do not be afraid of challenging the conclusion that what the expert is putting forward is too good to be true. It is also worth examining the language

in which the expert expresses himself. For example, does it

sound partisan?



The choice of expert can make or break a case. In the world of single joint experts, his may be the only evidence before the court. Litigators must bear in mind the court's advice from the Ikarian Reefer (1993) that an expert 'should never assume the role of an advocate' - if he has, the lawyer has hired a cowboy. This can be avoided if litigators have the discipline to choose carefully when selecting experts.



Henry Bermingham is vice-president of the Forum of Insurance Lawyers and a partner at City-based Berrymans Lace Mawer