Expert Witness

expert witness

Modern technology and recent advancements in forensic science and medical tests have paved the way for a more accurate determination of a case. The Courts are obligated to determine all cases that are referred to them. They cannot escape their responsibility by pledging ignorance on a particular subject matter. Therefore, it is imperative to have experts guide the Courts in technical areas such as DNA testing, blood sample testing, finger print test, handwriting test among others. The requirement for experts have been recognized and elucidated under Section 45 of the Indian Evidence Act, 1872.[i]

Section 45 of the Act,[ii] defines experts as those who are especially skilled in a given field. The opinion of these experts in the field of science, arts or foreign law, that helps facilitate the Court to come to a conclusion.[iii] The provisions elucidated under Section 45 to 51 of the Indian Evidence Act which provides for the relevancy of experts. Before expert’s testimony is put under consideration, it is imperative to establish, that there is a requirement for an expert’s opinion and the subject matter is of relevance to the case. Further, it is required to establish that the expert is indeed an ‘expert’ of his field of choice. After the competence and relevance of the expert’s opinion is established the evidence put forth is admissible under the Court of law. However, the discretion to accept or reject the opinion lies with the Court.

Illustration: A shot B with a gun. B subsequently died. A ballistics report will be provided by the expert to establish that the bullet came from the gun that A owned.

Who is an expert:

An expert witness is a person who has skill, knowledge, devoted time and has undergone training in a field he deems to be an expert.[iv] An expert is not a witness of fact but the evidence provided by him has an advisory character. It is the duty of the expert witness, to provide necessary information and scientific criteria to enable the judge to form his own independent opinion.[v] It is upon the Court to determine whether the skills and knowledge amounts to an expert’s opinion. Both plaintiff and respondent have the privilege to bring in an expert to assert and supplement evidence. The merits of the expert can be challenged during cross examination, by evident fallacies in the method applied and if contrary evidence is proved.[vi] It is a general exception to the rule against giving an opinion in the trial. Generally, a witness is one who has seen, heard or experienced criminal activity in question.[vii] However, an expert witness is a witness due to his skill, knowledge and discipline in a particular field. The opinion provided by the expert will be considered admissible evidence after the Court has scrutinized the method employed and opinion generates conviction.[viii] If the expert cannot be present due to extenuating circumstances, his opinion can be taken in a way of affidavit, written questionnaire, telephonic conversation or even video conferencing.[ix]

What is the evidentiary value of an expert’s opinion:

The opinion of an expert should be supported by the facts and circumstances of the cases, contradiction due to other evidence or fallacies in the findings of the expert render the evidence inadmissible and unreliable.[x] In the case of Forest Range Officer v. P.Mohammad Ali,[xi] it was concluded that an expert’s opinion is not binding upon the court. Further the opinion of an expert cannot supersede evidence of an attesting witness. A conviction cannot be based solely on the opinion of an expert without substantial corroboration.[xii] As per Section 293 CrPC, the report of specific Government scientific experts will be considered admissible evidence during inquiry, trial or other proceedings of the court, where the court is able to summon and examine the experts.[xiii]  If there is a conflict of opinion, the Court has the final say in the matter.[xiv]  In the case of Ram Narain Singh v. State of Punjab,[xv] the evidence provided by the expert and that of the normal witness was colliding, thus considered unreliable by the Court. The prosecution subsequently failed to establish their ground and the accused was acquitted.  Furthermore, an expert can only formulate an opinion if all the required material is provided to him, if his opinion is based on incomplete documents, it cannot be relied upon.[xvi] Since both the parties have the privilege to call an expert, the probability of favoritism is extremely high; therefore it is imperative to approach expert’s evidence with great caution. In the case of State of Maharashtra v/s Damu s/o Gopinath Shinde and others,[xvii] it was held no reliance can be places if expert is not examined as a witness.[xviii] The opinion of the expert should be limited to the content referred to him, anything beyond that would not be admissible in the Court.[xix] Section 48 of the Act,[xx] widens the scope of experts. Thus, historians can be referred to, in cases where the relevant fact is pertaining to customs and rituals.

What are the areas wherein an expert’s opinion is required:

Foreign Law:

Law which is not implemented or applicable in India is considered foreign law. Law which is not in force in India is foreign law.[xxi] A judge is required to interpret and apply all the laws of the land however it is not expected from a judge to be an expert in foreign law as well. There is no necessity to call in an expert as foreign law can also be proved under section 38 by production of a book printed by the authorities. Foreign law is considered a question of fact.[xxii] In the question of Hindu Law and Mohamedan Law, the opinion of the expert would be irrelevant as the onus to interpret and rightfully implement the laws is upon the Court.[xxiii]

Science or Art:

The terms Science and Arts are broadly constructed to inculcate various fields under this category. These terms include all subjects pertaining to Science or Art. These terms are not limited by the narrow understanding of ‘science’ and ‘arts’.

Medical Experts:

The opinion of a medical officer and reports are generally considered as evidence. The opinion of the doctor who conducted the initial post mortem or inspected the injuries of the victim supersede the opinion of the subsequent doctor who formulates opinion based on X-ray reports, post mortem reports and other medical tests. However, if the essential tests are not preformed and opinion is formulated on limited grounds, the opinion of the medical officer will not be relied upon. Test such as DNA test which are highly conclusive in nature are relied upon unless mishandling or corruption of the report is proved. In certain cases, wherein the question of legitimacy of child is in question, DNA test are directed as a routine procedure, but reasons for the same are to be recorded

Handwriting Expert:

The opinion of a handwriting expert is admissible under Section 45 of the act, however it is not binding. The evidence of handwriting cannot be considered a conclusive proof. Thus, conclusion cannot be solely derived from it. The opinion of a handwriting expert requires further corroboration to be considered reliable either direct or through circumstantial evidence. In the case Fakhruddin v. State of M.P,[xxiv] the Supreme Court gave guidelines for proof of documents; by direct evidence, by expert’s evidence and finally by court through the method of comparison. The opinion of handwriting experts is also applicable in criminal cases. In the case of State of Maharashtra v Sukhdev Singh,[xxv] court laid down the following principles. has laid down the principles of judging opinion of handwriting expert, namely;

1. The identification done through handwriting does not share the same merit as identification done through finger prints. In comparison more weight is given to finger prints as opposed to handwriting.

2. Corroboration is required as handwriting is evidence is a weak form of evidence and cannot be relied upon solely.

3. The genuineness of the specimen handwriting as that of the suspect must be established.

4. Expert’s competence, reliability and ability needs to be established before the Court.

5. The reason for the expert’s findings and opinion should be based on a scientific principle and should be convincing in nature

6. The Court should be caution in basing its judgment on the opinion of the expert.


Examination of finger prints as opposed to handwriting is a matter of science. Since finger prints cannot be changed nor can there be several opinions pertaining to the same.  Such evidence can be admissible in Court without corroboration. Furthermore, finger prints are unique and no man can have same finger prints.

Foot prints:

Foot impression do not have same evidentiary value as finger prints. The science of foot impression is archaic and rudimentary. Thus, it cannot be considered reliable with proper corroboration.

Firearms Experts:

The ballistic reports are used to establish that a particular bullet came from a specific firearm.[xxvi] The science of ballistics is helpful to determine the distance, severity and the type of weapon that was used to commit a crime. The report of ballistics is often considered essential in cases where firearms are used. The report is admissible without calling the expert to appear as a witness. If report is provided without examining the wound or the firearm but done through examining the pictures, such a report was considered unreliable.[xxvii] Therefore, the firearms or ballistic expert must formulate his opinion through his own findings and observation

Drugs and Narcotics:

The presence of drugs or narcotics can be done through a blood test report.

Examiner of Electronic Evidence:

As per Section 79-A of the Information Technology Act, 2000 (21 of 2000),[xxviii] in the matter of examination of electronic evidence, the opinion of the examiner is a relevant fact.


It is evident that the scope and the areas wherein expert witness can be called for has widened due to advancements and various judgments. However, due to various factors such as partiality, favoritism, indirect involvement, the evidence submitted by an expert witness cannot be solely used to base conviction. This form of evidence is generally considered weak evidence that requires further corroboration. However, evidence that are based on scientific principles and are not dependent on the opinion of the expert such as finger prints, blood test, DNA test have a stronger evidentiary value. The onus to prove the reliability of the expert’s witness evidence is upon the party calling for an expert witness. As a rule of thumb, Courts are cautious reviewing expert’s evidence.

Frequently Asked Questions:

1. Whether conduction DNA test and relying on the same is against Article 20 of the Indian Constitution?

DNA test has been argued to be against the Fundamental right Article 20 which provides safe guard in terms of self incrimination. However the matter is still debated upon without an absolute answer provided by the Supreme Court on this matter. The last case of reference was Azmal Kasab case, wherein it was held to be unconstitutional and against basic rights.

2. Whether corroboration is a necessity?

The Supreme Court in the case of Murarilal v. State of MP, stated that there is no rule of law that requires exert witness evidence to be corroborated.

3. What are the other kind of experts that can be called upon?

Motor vehicles inspector, evaluation of property, tracker dog, psychological autopsies, ear print comparison, palm impressions, chemical analyzer, nautical assessors among others.

Edited by Shuvneek Hayer
Approved & Published – Sakshi Raje


[i] The Indian Evidence Act, 1873,§45(India).

[ii] Ibid.

[iii] Titli v. Jones, AIR 1934 All 237.

[iv] Sri Chand Batra v. State of U.P. AIR 1974 SC 639.

[v] State of Himachal Pradesh v. Jai Lal and others, AIR 1999 SC 3318

[vi] Ibid.

[vii] Mr. Sreeraj.K. V, Relevance of expert witness in criminal law, IPLEADERS, (Jan 28,2019,4:00 PM)

[viii] State Of Himanchal Pradesh v. Jai Lal,AIR 1999 SC 3318

[ix] Code of Civil Procedure,1908, Rule 4 in Order 18 CPC (India)

[x] Ratanlal and Dhirajlal, The Indian Evidence Act, 233-235, (21st Edition) Lexis Nexis Butterworths Wadhwa, Nagpur

[xi] Forest Range Officer v. P.Mohammad Ali, 1994 AIR 120, 1993 SCR (3) 497

[xii] Murali Lal v. State of Madhya Pradesh, 1980 AIR 531, 1980 SCR (2) 249

[xiii] Mr. Sreeraj.K. V, Relevance of expert witness in criminal law, IPLEADERS, (Jan 28,2019,4:00 PM)

[xiv] Forest Range Officer v. P.Mohammad Ali, 1994 AIR 120, 1993 SCR (3) 497

[xv] Raj Narain Singh v. State of Punjab 1975 AIR 1727

[xvi] Ramesh Chandra Agarwal v/s Regency Hospital Ltd, Civil Appeal No.5991,2002

[xvii] State of Maharashtra v/s Damu s/o Gopinath Shinde and others, AIR 2000 SC 1691

[xviii] State of Maharashtra v/s Damu s/o Gopinath Shinde and others, AIR 2000 SC 1691

[xix] Kabul Singh v/s Gurinder Singh, 1991,21 PLR 816

[xx] The Indian Evidence Act, 1873,§48(India).

[xxi]The free dictionary by Farlex,,(visited on 29thJan, 2019).

[xxii] Khoday Gangadhara v. Swaminath Mudali 1926 Mad 218

[xxiii] Aziz Bano v. Mohd. Hussain 47 All 823

[xxiv] Fakhruddin v. State of M.P,AIR 1967 SC 1326

[xxv] State of Maharashtra v Sukhdev Singh, 1992 AIR 2100, 1992 SCR (3) 480

[xxvi] Kalua v. State of U.P. 1958 Cr. LJ 30 SC

[xxvii] Mohan Singh v. State of Punjab AIR 1975 SC 2161

[xxviii] The Information and Technology Act, 2002,§79-A,(India)

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I am Anushka from O.P Jindal Global University, Sonipat, pursuing BA.LLB (2016). My major interest lies in Arbitration Law, International Law, Criminal Law, Intellectual Property Law and Corporate Law. Apart from legal interest, I am a dedicated social worker and President of Legal Aid based Ngo- Sarthak Disha Foundation. We focus primarily on women related issues and human rights issues. I am an ardent reader, my preference ranges from fiction to non fictional content. I dedicate majority of my time towards mooting, negotiation competitions and attending seminars on socio-political as well as environmental issues.