Expert Witnesses – who are they and how can they help you?


A huge thank you and well done to Matt, our work experience student from Newcastle University, for helping to put this article together!

Who are Expert Witnesses?

Technically, expert witnesses can be anybody with vocational or academic experience beyond that of a ‘layperson’ (the average person on the street). The Medical Defence Union suggests that a practitioner has 10-15 years’ experience in a particular discipline to acquire sufficient knowledge, but in other areas the suitability of a candidate may be assessed differently. The level of expertise required to be an expert witness was confirmed in the case of Hoyle v Rogers [2014] EWCA Civ 25, when the Judge stated that the, “bar to be surmounted” to be an expert is, “not particularly high”.

Further to this, Expert Witnesses are also likely to have a good understanding of Court procedures and rules, and must be prepared to give an objective opinion and have it examined by the Court.

What cases might need an Expert Witness?

Expert Witnesses can be instructed for a huge range of subjects; LFBB’s office copy of Dr Chris Camplin’s UK Register of Expert Witnesses lists jewellers, agricultural consultants, forensic accountants and toxicologists, among a myriad of others. Cases which need expert witnesses can be criminal or civil, and the subject matter will likely be something that a Judge – a legal expert – couldn’t be expected to have a detailed understanding of. For instance, a personal injury claim following a road traffic accident which requires the opinion of an orthopaedic surgeon or a property dispute which requires the assistance of a chartered surveyor.

Certain criminal cases might require an expert witness if there is an aspect of diminished responsibility or if a psychological assessment is required. A well-publicised case that swung upon the opinion of expert witnesses was that of Sally Challen. Sally Challen was imprisoned for life – convicted of murder after killing her abusive husband with a hammer. An appeal was brought using a psychologist as an expert witness and Sally’s conviction for murder was reduced to manslaughter – she was released from prison after time already served.

What do expert witnesses do?

Expert witnesses will provide a report and may attend Court to give their impartial opinion. They may be instructed by one side (known as a Party Appointed Expert) or both (known as a Single Joint Expert), but in both cases their duty to assist the Court overrides any duty to the party who instructs or pays them. There are very strict rules governing the admissibility of expert evidence, so the expert must make sure they comply with these. In the recent case of Fawcett v Tui UK Ltd [2023] EWHC 400 (KB), the Court held that despite arguments that the expert witness was impartial, underqualified and had overreached his remit, the Court is the best place for admissibility to be decided and allowed the expert’s evidence.

Expert witnesses do not-

  • Argue a case – this is a job for the lawyers
  • Opine on areas beyond their specific area of expertise
  • Advise parties

Ensuring you select and instruct the correct expert for your dispute is a key part of ensuring success in litigation. If you are unsure what to do, it is best to take competent legal advice on the subject. Many cases have been won and lost on the strength of a party’s expert.

Do you have a problem that you need help or advice with? Make sure you speak to our litigation lawyers on 0114 2729721 who will be happy to assist.

Contact us for more information

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