Legal responsibilities of an expert witness

Legal duties and responsibilities

These duties and responsibilities include:

• Expert evidence presented to a Court should be, and should be seen to be, the independent product of the Expert Witness
• An expert witness should provide independent assistance to the Court by giving an objective unbiased opinion on matters within his/her area of expertise
• Although most likely paid by one of the parties to the litigation and receiving instructions from that party’s lawyer, the expert’s role is always to be objective and to help the Court on matters within the expert’s expertise
• The facts and assumptions on which an expert’s opinion is based should be clearly stated
• Being objective, the expert should consider material facts even if these could detract from the expert’s concluded opinion
• An expert witness should clearly indicate where a particular question or issue falls outwith his/her specialist area
• If the expert has insufficient data to finalise his/her opinion the expert witness must indicate that his/her opinion is provisional only
• If, following an exchange of reports with the expert acting for the other party, the expert changes his/her views on a material matter, then that change of view has to be communicated to the other party / the Court as necessary

Obtain a clear brief from the client’s lawyer as to what is required of you and any relevant time limits. If you need access to information held by third parties (eg. medical records) be clear as to who is to be responsible for obtaining these.

Confidentiality and conflicts of interest

Confidentiality is of critical importance. You should not disclose the name of the client or any other of their details or make any public statements regarding the case except with the prior consent (always best to have this in writing) of the client or their lawyer or, if authorised, by the Court.

Failure to do this could, in the worse case scenario, result in you either being found guilty of contempt of court, which has serious consequences, or being sued for damages.

You should, however, disclose any actual or potential “conflict of interest” to the client or their lawyer.

Such conflicts of interest include any personal, professional or financial interests, either in the parties to the litigation or the subject matter of the dispute.

Acting as an Expert Witness in an English Court

Although the legal responsibilities under Scottish and English law are similar, if you are acting as an expert witness in a case going before an English Court you may want to familiarise yourself with the detailed rules set out in the Civil Procedure Rules 1998 (Part 35).

Expert Witness reports

Assistance on what to include in an expert witness’ report can be found on the websites of The Law Society of Scotland and The Expert Witness Institute.