A Glance on What is Expert Opinion

Expert opinion is governed under section 45 of Evidence Act 1950. My discussion is inclined more onto academic discussion which hopes to provide a glance and quick understanding on what is expert opinion.

First of all, I would like to apply the illustration given under section 45 in order to give a clear picture that when expert opinion is needed. For instance, when court comes to the question as to whether the death of victim was caused by poison. Then, the opinions of experts as to the symptoms produced by the poison by which victim is supposed to have died are relevant in assisting the judge to reach a decision.

The second example is when there is issue as to whether a certain document was written by A. Then, the opinions of experts on the question whether the two documents were written by the same person or by different persons are relevant to assist the court to decide on the authenticity of the document.

However, we shall bear in mind that there is difference between evidence of fact and evidence of opinion. The primary difference is ordinary rules of admissibility will apply to former but not as to latter because it falls under the category of expert evidence.

I would like to cite what Hobhouse J had said on expert evidence in The Torenia [1983] 2 Lloyd’s Rep 210 which had been applied in Khoo Hi Chiang v PP [1994] 1 MLJ 265, in elaborating on the difference between evidence of fact and evidence of opinion.              

•  First, evidence is adduced which can be described as direct factual evidence, which bears directly on the facts of the case;
• Second, there is opinion evidence which is given with regard to those facts as they have been proved, and then;
• Thirdly, there is evidence which might be described as factual, which is used to support or contradict the opinion evidence. This is evidence which is commonly given by experts, because in giving their expert evidence they rely upon their expertise and their experience, and they do refer to that experience in their evidence. So, an expert may say what he has observed in other cases and what they have taught him for the evaluation of the facts of the particular case. So, also experts give evidence about experiments which they have carried out in the past or which they have carried out for the purpose of their evidence in the particular case in question.”

Expert evidence is important and we cannot expect the judge to know everything. Definitely, there have been some areas which are beyond the experience and knowledge of a judge. Therefore, expert evidence will then be admissible and come into play by furnishing the court with the scientific knowledge to assist the judge.

Abdul Hamid FJ in Syed Abu Bakar bin Ahmad v PP [1984] 2 MLJ 19 had also stated that: “There are however cases in which the court is not in a position to form a correct judgment without help of persons who have acquired special skill or experience on a particular subject, eg when the question involved is beyond the range of common experience or common knowledge or hen special study of a subject or special training or special experience therein is necessary. In such cases, the help of experts is required. In these cases, the rule is relaxed and expert evidence is admitted to enable the court to come to a proper decision.

I also would like to cite the opinion of Yong Pung How CJ in the case of Chou Kooi Pang & Anor v PP [1998] 3 SLR 593, 598:“Further, it is well established that expert opinion is only admissible to furnish the court with scientific information which is likely to be outside the experience and knowledge of a judge. If, on the proven facts, a judge can form his own conclusions without help, the opinion of an expert is unnecessary. (R v Turner [1975] QB 834) Thus, a psychiatrist’s evidence was held inadmissible where its purpose was, in effect, to tell a jury how an ordinary person, not suffering from any mental illness, was likely to react to the strains and stresses of life. (R v Weightman (1991) 92 Cr App R 291)