Former truck driver Kevin Callan took the legal and medical profession to task last year when he proved that he could not have caused the death of his girlfriend's daughter, despite being given a life sentence for her murder.

Callan spent four years in prison studying neurology in order to prove that four-year-old Mandy, who had suffered from cerebral palsy, could not have died from being shaken, as the court heard, but in fact died from a fall.

By uncovering new medical evidence Callan won his case at the Court of Appeal. Richard Henriques QC for the Crown appeal wrote to Callan's defence before the case conceding that: “Because of the mass and weight of Callan's evidence our own evidence has been annihilated.”

If Callan had not taken it in to his own hands to challenge his conviction he could still be serving a life sentence for an injustice caused by the use of an inappropriate expert witness.

His original trial concerned the death by brain damage of a child suffering from cerebral palsy. The Crown used two experts – a pathologist and a consultant paediatrician – but neither was a specialist in neurology.

Campbell Malone, senior partner at Salford firm CJ Malone, which acted for Callan in his appeal, says: “The original case went all the way without any satisfaction that the right experts were appointed.”

Callan, who is writing a book and making a documentary about his experiences with the English criminal justice system, says: “Experts who are experts in particular spheres should comment upon nothing but those areas.

“The word of an expert is taken as solemn and infallible. When misinformed evidence is given in court it is like showing a red flag to a bull. It misleads a jury. It also allows a judge to comment in misleading ways, but, most importantly, it causes many miscarriages of justice.”

Michael Mansfield QC, who represented Callan at the appeal, says the case highlighted the urgent need for changes in the system of expert witnesses. He says the Appeal Court originally refused Callan a hearing because it said he was conducting a “trawl for experts”.

Mansfield adds: “I am very conscious now in the Court of Appeal that there is a different wind blowing and it is being strict about the number of experts. I keep hearing the phrase 'we cannot allow you to have a bite of the cherry'.

“The difficulty is science is seen as being written in tablets of stone. But it is highly subjective. If you look at all the miscarriages of justice in the past 10 years, 80 per cent have got an element of unreliable scientific evidence.”

He calls for a national independent forensic science service, properly funded with legal aid, and an institute of forensic science for research and training with a recognised register of experts.

The Callan case expert witnesses were unavailable for comment.

The Academy of Experts, formed in 1987, runs an experts search service for the legal profession, with 1,500 accredited experts on its books.

Academy chair Michael Cohen, a barrister and expert witness in insurance matters, says: “I sit as an arbitrator hearing disputes and I consider some of the experts who appear before me to be hopelessly incompetent, not necessarily because they are not technically sound but because they do not understand the requirements of being an expert witness.”

He says problems could be eliminated by courts insisting that expert witnesses are properly qualified and are bound by a code of practice with disciplinary sanctions attached.

At present there is some concern over the absence of a uniform accreditation system for expert witnesses used in court.

In theory, experts do not have to have any kind of recognition or accreditation, although there is a motley collection of institutions and directories which claim to list bona fide experts. Among them is the academy, the Law Society's Directory and the Association of Vehicle and Motor Accidents' list. Training schemes are run by the academy and Bond Solon Training.

Obstetrician and gynaecologist and editor of Clinical Risk magazine Roger Clements organised a conference last year on expert witnesses in the medical negligence field.

The conference was run as part of the Woolf inquiry into expert witnesses and formed a section of his on-going report on civil justice.

He says: “The average high street solicitor has no access to any accreditation board. The recently published Law Society directory seemed promising but because it only requires each expert to have two references it is not worth the paper it is written on.”

Clements calls for stricter regulation over the suitability and expertise of experts, and across-the-board practical training on how to present evidence in court and fulfil the role of an expert witness.

He adds: “At the moment it is not realistic to expect the Lord Chancellor's Department to fund such regulatory procedures.

“There might, however, be support for the Royal Colleges to run schemes. Experts could pay for their accreditation themselves, thus paying for themselves to be given the right to give evidence in court.”

Michael Green, professor of forensic pathology at the University of Sheffield and chair of the forensic pathology sub-committee of the Royal College of Pathologists, believes his profession, which is largely used in criminal courts, is adequately supervised by the Home Office. He says: “I think the Home Office should continue to regulate rather than the Royal College. In any field of law, however, any expert who is not up to scratch will be torn to pieces and exposed in a court. It's a harsh and cruel spotlight once you are out there in the witness box.”

John Friend, obstetrician and gynaecologist at Derreford hospital in Plymouth and spokesman for the Royal College of Obstetricians and Gynaecologists, says of Clements' proposals: “I think it would be a shame to have a two-tier level of experts and non-experts within the college.

“It is up to lawyers to inform their experts and to extract the information they need.

The kind of controls being suggested for experts are going too far.”

Mark Solon, partner at Bond Solon, runs independent training schemes for expert witnesses. He believes the problem with the system at the moment is that expert witnesses do not know how to react in a courtroom situation.

He says: “Experts are often unaware of legal practices and procedures and even though an expert may have produced many reports, they may never have given oral evidence. And they often have no training at all in this role.”

Jeffrey Bayes, a partner at Burton Copeland, believes solicitors are as much to blame as experts in “getting it wrong”. He has formulated his own directory of experts which was initiated after he was involved in a robbery case. An expert analysed a hair found in the getaway car and found it to be that of the defendant. It was later found to be a dog hair.

“This case illustrated to me how important it is to find a proper expert witness,” says Bays.

“I think there is little evidence to suggest that the system does not work. There are generally lots of pitfalls in instructing experts such as selecting the right person and the right evidence. You simply cannot legislate against mistakes happening occasionally.”

Kevin Callan's solicitor Campbell Malone says it is unclear whom Callan should pursue in his search for some kind of compensation: “His solicitors for the case could be sued for professional negligence if it can be proved that they didn't perform to an acceptable level.

“It is also clear that very serious errors were made by the Home Office pathologist. The court could also be held to task for acknowledging misleading evidence.”

Vox Pop

Mark Solon of Bond Solon Training says: “Because lawyers are paid to win, there is a temptation for them to 'improve' on what the experts have said, thus experts can become hired guns.”

The view held by Robert Radley, a forensic document examiner, is that “there are an awful lot of cranks advertising themselves in the legal press as expert witnesses. This has a bad effect on the reputation of forensic document examiners in Britain.”

Jacqueline Sawyer, also a forensic document examiner, adds: “There is a great deal of snobbery amongst those forensic document examiners who have had official Home Office and police training directed towards those who haven't. In this field practical experience is far more important than qualifications.”

Senior nurse manager Estelle Deli-Tucker says: “Before I was trained as an expert witness I had a very limited understanding of legal jargon and was intimidated by the courtroom environment and the questioning techniques of the counsel.”

Woolf's recommendations

Lord Woolf's report on the legal system, Access to Justice, recommended the use of court appointed expert witnesses.

Rather than having two expert witnesses giving opposite views, with one acting for the prosecution, the other for the defence, there would be a sole representative who would give an objective view.

Solicitors, however, are generally not in favour of the system.

The Official Referees Court is the only court in the UK where court appointed witnesses have been used.

Robert Fenwick Elliott, senior partner at Fenwick Elliotts, who has had experience of such a system, says: “There are circumstances where the appointment of court-appointed experts could result in significant savings of cost and time. This is especially so where the issues depend upon large numbers of comparatively uncontentious facts.

“To some extent, however, the use of court appointed experts represents cheaper and perhaps rougher justice than the usual adversarial system.”