Earlier, the Courts required expert evidence to some limited field i.e. medical doctors, engineers, architects, stockbrokers etc. With the vast development in science and technology, the need of expert opinion/evidence has now become very common as well as helpful to the Courts to reach upon a fair conclusion regarding commission of an offence. Today the role of experts has been widened and the Courts take their assistance in various aspects viz. ballistic experts, forensic experts, scientists who decide the legitimacy by DNA tests, chemical examiners, psychiatrists, radiologists and even track-dogs are playing a vital role in investigation of crimes and their evidence is admissible in the court of law.

When there is some technical issue or such issue which relates to foreign law or of science or art, or as to identity of handwriting or finger impressions and the Court has to form an opinion upon that point, then the opinion of skilled/experienced persons in their respective areas may be taken into consideration.

Expert evidence in Indian Evidence Act

Expert evidence is covered under Ss.45-51 of Indian Evidence Act. S.45 of the Act allows that when the subject matter of enquiry related with science or art, as to require the course of previous habit or study and in regard to which inexperienced persons are unlikely to form correct judgment. It allows an expert to tender evidence on a particular fact in question and to show to the court that his findings are unbiased and scientific.S.46 of the Act states that facts, not otherwise relevant, are relevant if they support or are inconsistent with the opinion of experts when such opinions are relevant. S.47 of the Indian Evidence Act exclusively deals with the opinion as to the handwriting. The explanation further elaborates the circumstances under which a person is said to have known the disputed handwriting. The expert opinion is not confined to handwriting alone. The opinions in relation to customs are also admissible according to S. 48 of Indian Evidence Act.

The next question that arises is who can be called an Expert, what is the function of opinion given by expert in a matter before Court and further what is the character of opinion/advice adduced by an expert in forming opinion by the Court?

Hon’ble Supreme Court in the case titled as Ramesh Chandra Agarwal v/s Regency Hospital Ltd. has broadly dealt and interpreted the scenario and held that, an expert is a person who devotes his time and study to a special branch of learning. However, he might have acquired such knowledge by practice, observation or careful study. The expert is not acting as a judge or jury. It was further held that in order to bring the evidence of a witness, as that of an expert, it has to be shown that he has made a special study of the subject or acquired a special experience therein or in other words that he is skilled and has adequate knowledge of the subject. The real function of the expert is to put before the Court all the materials, together with reasons which induce him to come to the conclusion, so that the Court, although not an expert, may form its own judgment by its own observation of those materials. An expert is not a witness of fact (like other witnesses) and his evidence is really of an advisory character. The duty of the expert witness is to furnish the Judge with the necessary scientific criteria for testing the accuracy of the conclusions so as to enable the Judge to form his independent judgment by the application of these criteria. No expert can claim that he could be absolutely sure that his opinion was correct.

Hon’ble Supreme Court has further laid down in the case titled as State of Maharashtra v/s Damu s/o Gopinath Shinde and others, AIR 2000 SC 1691, that mere assertion without mentioning the data or basis in support of his opinion is not evidence, even if it comes from an expert. It is held that such evidence though admissible, may be excluded from consideration as affording no assistance in arriving at the correct value without examining the expert as a witness in Court. Therefore, no reliance can be placed on an opinion alone.

In the case titled as Kabul Singh v/s Gurinder Singh, opinion of the expert was sought regarding signatures put on a document. However, the expert also gave opinion that certain digits were changed which opinion was not sought for. The Hon’ble High Court of Punjab and Haryana held that such an opinion should be ignored and that expert should have confined himself to the relevant facts.

However, there is a probability to lean the opinion of private experts in favour of the party calling them. In such like cases, when there is a conflict of opinion between the experts, then the Court is competent to form its own opinion with regard to signatures on a document or such like matters.

Another important issue under consideration is that whether the Courts are bound by the opinion given by an expert on a particular fact in a case. Hon’ble Supreme Court has answered this question in the case titled as Malay Kumar Ganguly v/s Dr. Sukumar Mukherjee, wherein it has been held that, a Court is not bound by the evidence of the experts which is to a large extent advisory in nature. The Courts have full powers to derive its own conclusion upon considering the opinion of the experts which may be adduced by both sides, cautiously, and upon taking into consideration the authorities on the point on which he deposes. The opinion could be admitted or denied. Whether such evidence could be admitted or how much weightage should be given thereto, lies within the domain and discretion of the Court. The evidence of an expert should, however, be interpreted like any other evidence.

Thus, it can be concluded that the expert opinion in numerous matters relating to identification of thumb impression, handwriting, footprints, fixing paternity, time of death, age of the parties, cause of death, possibility of the weapons used, disease, injury, sanity and insanity of the parties and other question of science or trade has become the need of hour and the person having required skill on that subject (called experts), are allowed to give their opinions in evidence as well as testify to facts/details leading to their opinion. The opinion of an expert having special skill in that particular field is relevant for the point of admissibility before the Court of law. There may be exceptions to this rule, in spite of it when there direct evidence is lacking, then to corroborate the existing evidence, expert opinion is sought.