Generally, when a person is summoned to court for giving testimony as a witness, he is expected to state only facts and not to give any opinion. It is the job of the court to form an opinion in the case. Moreover, if a person is asked to give his testimony then it is expected that the person must be factually related to the case not merely a third party.
But there is an exception to this rule. The experts are considered as witnesses although they are not actually related to the case. The court requires these experts to give an opinion regarding the case to help the court in having a wider perspective to give justice. The rationale behind the same is that it is not practical to expect the Judges to have adequate knowledge of medical issues.
When the court needs an opinion in a subject which requires special assistance, the court calls an expert, an especially skilled person. The opinion given by a third person is considered as relevant facts if the person testifying is an expert.
For example, the court was confused that a letter has been written by person ‘X’ or not. The court calls a handwriting expert to find out the same. This person will be known as an expert and the opinion which he gives in the case is relevant.
Expert is defined under section 45 of THE INDIAN EVIDENCE ACT, 1872 The court needs an expert to form an opinion upon:
- Foreign law
- Science & Art
- Identity of Handwriting
- Identity of finger impression
- Electronic evidence
The court of law, before admitting any of the opinion made by an expert, needs to ensure that the person is an expert under the law. If it is found that the person is not an expert, his opinion is discarded by the court. For checking that the witness is an expert, he must be examined and cross-examined. A person becomes an expert by:
- Observation, or
HANDWRITING EXPERT SECTION 47
The handwriting of a person may be proved in the following ways:
- A person who is an expert in this field
- A person who has actually seen someone writing, or
- A person who has received any document which is written by the person whose handwriting is in question or under the authority of such person and is addressed to that person
- A person who regularly receives letters or papers which are written by that person
- A person who is acquainted with the signatures or writing of that person
- A certifying authority who has issued a digital signature certificate when the court has formed an opinion as to the digital signature of a person. This is mentioned under section 47-A of the act.
- The evidence of the writer himself. This is mentioned in section 60 of the act.
- If another person admits that the documents were written by him. This is mentioned in section 21 of the act.
- A person who has seen the person writing or signing. This is mentioned under section 6o of the act.
- When the court himself compares the document in question with any other document which is proved genuine in the court. This is mentioned in section 73.
- The court may ask the person to write something for the court to compare it with the document in question.
OPINION FOR ELECTRONIC EVIDENCE (SECTION 45A):
When a piece of information is transmitted or stored in a computer system and the court needs assistance or opinion for the same in any case; they refer an examiner of electronic evidence. This examiner of electronic evidence is known as the expert in such cases.
OPINION FOR FOREIGN LAW (SECTION 38 R/W SECTION 45)
When there is a law of prevailing in any foreign country which needs to be considered for giving judgment in any case, the court needs an expert who is well versed with that law.
Otherwise, the court can take opinion from a law-book which contains the answer regarding any foreign law. These books must be printed or published under the authority of the government of that country. Other reports of the ruling of the courts can also be taken as relevant which are given in such books of foreign law.
OPINION FOR FINGERPRINT
Generally, finger impression expert’s opinion is given more value because:
- The fingerprints of any person remain the same from their birth till death, and
- No two individuals’ are ever found to have the same finger impressions
Footprint studies are gaining importance nowadays but the courts have been reluctant to accept that as a piece of evidence.
OPINION FOR SCIENCE OR ART
The words ‘Science and Art’ are to be broadly constructed. The term ‘science’ is not limited to higher sciences and the term ‘art’ is not limited to fine arts, but having its original senses of handicraft, trade, profession and skill in work.
To construe that if any expertise comes under the head of ‘art’ or ‘science’; the following tests can be applied:
Is the subject matter of the injury such that inexperienced people are not capable of forming a correct judgment without the assistance of experts?
OPINION OF MEDICAL EXPERT
Opinions of a medical officer can be used to prove:
- The Physical condition of the person,
- Age of a person
- Cause of death of a person
- Nature and effect of the disease or injuries on body or mind
- Manner or instrument by which such injuries were caused
- Time at which the injury or wounds have been caused.
- Whether the injury or wounds are fatal in nature
- Cause, symptoms and peculiarities of the disease and whether it is likely to cause death
- Probable future consequences of an injury etc.
EVIDENCE OF TRACKING DOG
Trained dogs are used for the detection of crime. The trainer of tracking dogs can give evidence about the behavior of the dog. The evidence of the tracker dog is also relevant u/s 45.
WHAT IS THE EVIDENTIARY VALUE OF AN EXPERT OPINION
The data given by the expert are relevant and admissible. If any oral evidence contradicts the data/ report; it will not make the data evidence obsolete. But, as per section 46, in case any fact is in contradiction to the opinion of the expert, that fact becomes relevant. If the opinion of the expert is relevant, the contradictory fact becomes relevant even though it was not relevant as such. The value of expert opinion depends upon the facts on which he is based and the competency of such expert in forming a reliable opinion.
However, the personal appearance of the expert in the court can be excused unless the court expressly asks him to appear in person. In such a case, where the expert is excused, he can send any responsible officer who is well versed with the facts of the case and the report and can address the court with the same. The evidence given by the expert is just an opinion and is not a fact-based testimony and thus are given slight value. This is the reason that eye-witnesses or other factual witnesses are given a priority over the expert’s opinion. This is because opinion evidence cannot supersede substantive evidence. No expert can claim that he could be absolutely sure that his opinion was correct, expert depends to a great extent upon the materials put before him and the nature of the question put to him