Aug 12, 2019 by Foresight

A matter of opinion; what is an expert witness and what is their role?

We work alongside a broad spectrum of expert witnesses here at Foresight, and we are often approached by professionals looking to become an expert witness. This feature has been written by a forensic accountancy expert witness from our network, and details key facts about expert witnesses, their work and the legal implications of presenting their evidence and opinion.

An expert witness is one whose opinion, oral or written, may be used in connection with legal proceedings. Unlike other witnesses, who are confined to relating facts, an expert witness is the only witness who can express an opinion in court.

Experts are individuals with qualifications and/or experience which enable them to give an opinion on the facts of a case. Expert opinion is only admissible where the ordinary person could not decide on his own.

The Oxford Companion to Law describes expert evidence as:

evidence given to a court, by a person skilled and experienced in some professional or technical sphere, of the conclusions he has reached on the basis of his knowledge, from facts reported to him or discovered by him by tests, measurements or similar means”.

Courts are wary of appointing experts and will only do so if the evidence is reasonably required to resolve the proceedings justly.

The rules relating to experts are set out in Part 35 of the CPR – Civil Procedure Rules. The Criminal Code rules are very similar.

The seminal case for experts was the 1993 case of the Ikarian Reefer where it was recorded that:

“It is necessary that expert evidence presented to the court should be and should be seen to be the independent product of the expert uninfluenced as to form or content by the exigencies of litigation”. This has become known as the Cresswell Code after Mr Justice Cresswell, the judge in that case.

Being an Expert Witness means:

  • Being appointed as an expert witness – for a claimant or for a defendant or as a Single Joint Expert. SJEs are usually appointed for fast track cases or for large cases where technical or quantum issues arise.
  • Preparation of expert reports, affidavits, proof of evidence and giving oral evidence in court
  • ppointment as an Expert Adviser for either claimant or defendant
  • Being appointed as a Court appointed assessor

In short, being an expert means giving an opinion on issues based on facts found or established.

The most important piece of advice for an expert is: “Do not stray from your area of expertise”.


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