Understanding the role of the expert witness

In order to undertake the role, it is important to understand where your responsibilities lie in order to comply with the law

What is a witness?

A witness is a person giving sworn evidence to a tribunal or court of law. There are two types of witness:

  • witnesses of fact, who may give evidence of facts but may not normally give opinions
  • expert witnesses, who may give opinion evidence within their expertise as well as evidence of facts.

The appointment

An expert witness is appointed by the party to the dispute, although usually this is done by the party’s solicitor. Even though parties can appoint a joint expert, usually each party appoints their own.

Your duty

An expert witness has an overriding duty to the court (or other tribunal). This supersedes any duty owed to the appointing client, even though the client is responsible for paying the expert’s fees.

The court expects an expert witness to be independent and impartial, and will reject evidence of a witness who is seen to be partisan.

Your role

As an expert witness, you will be expected to:

  • provide an independent expert opinion in their area of expertise on the subject matter in accordance with the instructions you are given. These instructions will be shown in the expert witness’s report, which will be seen by the other side and the court
  • present your opinion in the form of an expert report, which contains information required by the court rules and/or evidence before a court (or other tribunal) as required. It is usually not possible for an expert witness to give evidence without it
  • provide truthful, impartial and independent opinions whether or not these opinions favour the case of the client who appointed you
  • comply with the specific procedure rules applicable and any Court or tribunal orders in the case.

As an expert witness, you will not:

  • be the advocate of the party who appointed you and argue their case
  • advise the party who appointed you on what information and evidence to present to the court
  • povide any opinion beyond your specific area of expertise
  • accept any appointment that results in a conflict of interest
  • accept any appointment on terms that are conditional on the outcome of the case. Examples of these are success fees or conditional fee arrangements (or any form of payment linked to the results of the case). Conditional terms are incompatible with the expert being seen to be independent
  • act as a negotiator.

Appointing party's requirements

The party who appoints you or their legal representatives should

  • agree contractual terms with you before the work is started in writing. These should include terms of payment. You can use standard terms provided by the Academy of Experts' model terms of engagement
  • provide you with all detailed instructions relevant to the case
  • keep you informed of developments in the case and of all key dates in good time.

Getting started

If you think the expert witness path may be for you, please contact Technical Advisory to express interest. Together with the Academy of Experts, we will be running an informal afternoon session, during which you will be able to find out more about the opportunities that the profession may offer you, get more information on the formal training that is available and ask questions.