Key elements to being a successful expert witness

Expert witnesses not only have to be knowledgeable in their own field of expertise but must also be aware of their considerable legal responsibilities. Their opinions can directly influence the outcome of a case, affect many people’s lives and even in some instances lead to changes in the case law.

Knowledge of the relevant parts of the law is important but the way an individual conducts themselves professionally and personally is also essential, according to Dr John Frazer, a consultant general adult psychiatrist with a special interest in forensic psychiatry who has provided psychiatric reports to the courts in England for more than 40 years.

He breaks it down to four specific areas: conflict of interest, impartiality, truthfulness and integrity.

Conflict of interest

Dr Frazer says: “Conflicts of interest can happen at any time during a case, and you must declare them as soon as possible and withdraw if one exists. You should be the judge if there is such a conflict. You should also be guided by those instructing you if they perceive one.

Below are some typical examples.

It is advisable to avoid acting as an expert in a case local to your geographical area. This is because you are more likely to have prior knowledge and views in relation to the relevant parties and issues.

If I know or have previously seen any of the parties in the case, I decline the instruction. You may be asked to comment if a colleague or colleagues previously known to you were negligent or acted criminally.

I had a potential homicide case involving a missing person. I discovered that I had worked with a potential defendant when I was a medical student many years previously. I pulled the plug immediately when I recognised him at the beginning of the interview. It would not have been fair to him or the court.

Another example would be accepting instructions from solicitors such that you are paid (like some lawyers) on a “no-win, no-fee” basis. Taking on such a case would make you a partial witness and bias (even unconsciously) your evidence to provide a positive outcome for those who've instructed you.

Your job as an expert is to always give a free and honest opinion which might not favour those who have instructed you.”

Impartiality

Remaining impartial is an essential element of the duty owed to the court by the expert witness.

Dr Frazer notes that: “If you are contacted directly by a claimant who asks you to act as an expert for them in court proceedings, you should tell them that you can only be instructed by courts or solicitors to protect your independence and impartiality. At no point should you be contacted separately by a defendant or claimant. Apart from the clinical interview any discussions or review of documents prior the preparation of your report should be declared clearly in the report.

Another example of an expert’s potential partiality are pre-existing views they hold or may have previously expressed in a public forum. This may skew their opinion when similar issues are involved in a particular case. 

Integrity as an expert witness can be built up over years but lost in an instant. It can then never be regained.”

Truthfulness

Truthfulness involves the expert giving their opinion based on all the information provided by those instructing them. This opinion can and should change in the light of new evidence.

“If you're provided with another document or a film which clearly shows you've not been told the truth or which contains new evidence contradicting what you have been previously provided with, your opinion must change,” adds Dr Frazer.

An example would be someone presenting believable and consistent psychological symptoms at interview. As psychiatrists and medical experts, we depend very much on the account given by claimants or defendants. But then evidence may be provided where they have been recorded performing activities which they have previously denied being capable of. This casts doubt on the veracity of their accounts.

You then must point out to the court that their account of symptoms and your subsequent diagnosis may also potentially be unreliable, as it is based on what they have said. That may not mean all their account is unreliable, but it may be that certain parts of it are and that should be clearly stated in evidence.

Another instance of unreliability of the evidence provided by claimants and defendants arises after the interview. You subsequently discover from their medical records that they've not told you about previous serious medical problems highly relevant to their current difficulties. The records may show they were significantly ill at the time when the index incident happened.

For example, occasionally a relatively minor accident can result in a claim for significant psychological damage. Forensically analysing medical records may reveal significant previous psychiatric problems more relevant or even causative of their current symptoms.

The facts in the records cannot be gainsaid. Similarly, if doctors claim to have performed an action in a medical negligence case and it is not recorded, then “they haven't done it.”

Integrity

Dr Frazer highlights that integrity is critical to being an expert witness and extends to standards of behaviour outside work.

He notes: “This means maintaining professional standards in accordance with the good medical practice as set out by General Medical Council. It is essential to treat everybody with respect such as those you are interviewing and those asking you questions. You must give the same answers no matter who asks you without fear or favour.”

At the end of each expert report the declaration states:

‘I understand my duty to the court and have complied and will continue to comply with it. I'm aware of the requirements of CPR Part 35 and Practice Direction 35, the Protocol for the Instruction of Experts to Give Evidence in Civil Claims and the Practice Direction on Pre-Action Conduct. I have made clear which facts and matters referred to in this report are within my own knowledge and which are not. Those that are within my own knowledge I confirm to be true. The opinions I have expressed represent my true, complete, professional opinions on the matters to which they refer. I understand that proceedings for contempt of court may be brought against anyone who makes or causes to be made a false statement in a document verified by a statement of truth without an honest belief in its truth.’

Dr Frazer adds: “If you breach that declaration when you sign that report, you can rightly be liable to criminal proceedings - all expert experts signing the declaration should always keep that in mind.”