Edited & Compiled for General Reading – Last Updated on May 19, 2015
An expert witness, professional witness or judicial expert is a witness, who by virtue of education, training, skill, or experience, is believed to have expertise and specialised knowledge in a particular subject beyond that of the average person, sufficient that others may officially and legally rely upon the witness’s specialized (scientific, technical or other) opinion about an evidence or fact issue within the scope of his expertise, referred to as the expert opinion, as an assistance to the fact-finder ((Federal Rules of Evidence – 2011 | Federal Evidence Review available at http://federalevidence.com/rules-of-evidence#Rule702)).
Expert witnesses may also deliver expert evidence about facts from the domain of their expertise. At times, their testimony may be rebutted with a learned treatise, sometimes to the detriment of their reputations. In Scots Law, Davie v Magistrates of Edinburgh ((1953 SC 34))provides authority that where a witness has particular knowledge or skills in an area being examined by the court, and has been called to court in order to elaborate on that area for the benefit of the court, that witness may give evidence of his opinion on that area.
By virtue of Section 45 of the Indian Evidence Act, 1872, when the Court has to form an opinion upon a point of foreign law or of science or art, or as to identity of handwriting ((Ins. by Act 5 of 1899, sec. 3. For discussion in Council as to whether “finger impressions” include “thumb impressions”, see Gazette of India, 1898, Pt. VI, p. 24. tc” 2. Ins. by Act 5 of 1899, sec. 3. For discussion in Council as to whether \”finger impressions\” include \”thumb impressions\”, see Gazette of India, 1898, Pt. VI, p. 24.”))[or finger impressions], the opinions upon that point of persons specially skilled in such foreign law, science or art, ((Ins. by Act 18 of 1872, sec. 4. tc” 3. Ins. by Act 18 of 1872, sec. 4.”))[or in questions as to identity of handwriting] ((Ins. by Act 5 of 1899, sec. 3. For discussion in Council as to whether “finger impressions” include “thumb impressions”, see Gazette of India, 1898, Pt. VI, p. 24. tc” 2. Ins. by Act 5 of 1899, sec. 3. For discussion in Council as to whether \”finger impressions\” include \”thumb impressions\”, see Gazette of India, 1898, Pt. VI, p. 24.”))[or finger impressions] are relevant facts. Such persons are called experts.
- The question is, whether the death of A was caused by poison. The opinions of experts as to the symptoms produced by the poison by which A is supposed to have died are relevant.
- The question is, whether A, at the time of doing a certain act, was, by reason of unsoundness of mind, incapable of knowing the nature of the Act, or that he was doing what was either wrong or contrary to law. The opinions of experts upon the question whether the symptoms exhibited by A commonly show unsoundness of mind, and whether such unsoundness of mind usually renders persons incapable of knowing the nature of the acts which they do, or of knowing that what they do is either wrong or contrary to law, are relevant.
The question is, whether a certain document was written by A. Another document is produced which is proved or admitted to have been written by A. The opinions of experts on the question whether the two documents were written by the same person or by different persons, are relevant. Comments Conflict of opinion of Experts 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 ((Kishan Chand v. Sita Ram, AIR 2005 P&H 156)). Expert opinion admissibility Requirement of expert evidence about test firing to find out whether double barrel gun is in working condition or not, not necessary ((Jarnail Singh v. State of Punjab, AIR 1999 SC 321)). The evidence of a doctor conducting post mortem without producing any authority in support of his opinion is insufficient to grant conviction to an accused ((Mohd Zahid v. State of Tamil Nadu, 1999 Cr LJ 3699 (SC).)). Opinion to be received with great caution The opinion of a handwriting expert given in evidence is no less fallible than any other expert opinion adduced in evidence with the result that such evidence has to be received with great caution ((Ram Narain v. State of Uttar Pradesh, AIR 1973 SC 2200)).