Significance of Scientific Evidence in Judicial Process

Jojy George


Hierarchy of scientific evidence – keys to scientific skepticism and  vaccines

Importance of testimony of witnesses in judicial process is expressed by the English philosopher and jurist Bentham about 150 years ago as: “Witnesses are the eyes and ears of justice” (State of U. P.  Vs. Krishna Gopal, AIR 1988 SC 2154).

An interesting question often arises- which will prevail, in case of a conflict between oral evidence or scientific evidence? The answer will be that it depends upon the nature of the subject matter. In everyday practice we see that trustworthy and credible oral evidence get primacy status over the scientific evidence. It is on the principle that the scientific evidence is always an ‘opinion’ or ‘possibility’ only. By the advent of scientific techniques in the field of judicial investigation and enquiry, our judicial process began to assign due importance to scientific evidence. Still, the oral evidence has primacy over the scientific evidence.  

Sec. 3 and 45 of the Evidence Act

On a broad classification, ‘evidence’ can be classified into following categories, according to Sec. 3 and 45 of the Evidence Act.

  • oral evidence
  • documentary evidence including electronic records
  • Opinions of experts including views of persons specially skilled in foreign law, science or art, or in questions as to identify of handwriting or finger-impressions. It may also be termed as scientific evidence.

Sec. 3 and 45 of the Evidence Act reads as under:

S.3: “Evidence”: “Evidence” means and includes:
(1) all statements which the Court permits or requires to be made before it by witnesses, in relation to matters of fact under inquiry, such statements are called oral evidence.
(2) all documents including electronic records produced for the inspection of the Court, such documents are called documentary evidence.

S.45: Opinions of experts: 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 or finger-impressions, the opinions upon that point of persons specially skilled in such foreign law, science or art, or in questions as to identify of handwriting or finger-impressions are relevant facts. Such persons are called experts.

Expert Evidence is only Corroborative

It is important that Section 45 of the Evidence Act does not say anything as to the weight to be attached to the expert evidence. This Section only says that expert’s evidence is admissible. The expert-evidence is not substantive evidence; and it is generally used as a piece of evidence for corroboration or conflict with oral evidence. The evidence of an expert only aids and helps the Court as advisory material. The expert being not a witness of fact, his opinion is to be analysed objectively by the court. The decision making process is never delegated to the expert; the expert only helps and assists the Court to decide. Courts always give due importance to the opinion of the experts. But, it will not substitute proof. Court is said to be the expert of experts.

In Solanki Chimanbhai Ukabhai v. State of Gujarat, (1983) 2 SCC 174, it was held that the evidence of eyewitnesses should be preferred unless the medical evidence completely rules it out. It was held as under:

  • “13. Ordinarily, the value of medical evidence is only corroborative. It proves that the injuries could have been caused in the manner alleged and nothing more. The use which the defence can make of the medical evidence is to prove that the injuries could not possibly have been caused in the manner alleged and thereby discredit the eyewitnesses. Unless, however the medical evidence in its turn goes so far that it completely rules out all possibilities whatsoever of injuries taking place in the manner alleged by eyewitnesses, the testimony of the eyewitnesses cannot be thrown out on the ground of alleged inconsistency between it and the medical evidence.”

In State of Haryana v. Bhagirath, (1999) 5 SCC 96, the Supreme Court held as under:

  • “15. The opinion given by a medical witness need not be the last word on the subject. Such opinion shall be tested by the court. If the opinion is bereft of logic or objectivity, the court is not obliged to go by that opinion. After all opinion is what is formed in the mind of a person regarding a fact situation. If one doctor forms one opinion and another doctor forms a different opinion on the same facts it is open to the Judge to adopt the view which is more objective or probable. Similarly if the opinion given by one doctor is not consistent with probability the court has no liability to go by that opinion merely because it is said by the doctor. Of course, due weight must be given to opinions given by persons who are experts in the particular subject.”

The blood group on the dress of the accused and the dress of the deceased matched. It corroborates the prosecution story. However that by itself is not conclusive proof of the culpability of the accused.[1]

In Surinder Singh v. State of Punjab, 1989 SCC (Cri) 649, it is observed that it would not be helpful to the prosecution if it was not shown that the blood-stains on the weapon recovered from the possession of the accused were of the same group as the blood of the deceased. (See also: Kansa Behera. v. State of Orissa.AIR 1987 SC 1507).

In State of U.P. v. Krishna Gopal, AIR 1988 SC 2154, the eye-witnesses were found credible and trustworthy. Therefore, the medical opinion pointing to alternative possibilities was not accepted as conclusive. The Apex Court pointed out that witnesses, as Bantham said, were the eyes and ears of justice. Hence the importance and primacy of the orality of the trial process. Eyewitnesses’ account would require a careful independent assessment and evaluation for their credibility, which should not be adversely prejudged making any other evidence, including medical evidence as the sole touchstone for the test of such credibility. The evidence must be tested for its inherent consistency and the inherent improbabilities.

Findings of a Serologist

As regards the findings of serologist, it is observed in R. Shaji v. State of Kerala, (2013) 14 SCC 266, as under:

  • “30. It has been argued by the learned counsel for the appellant that as the blood group of the bloodstains found on the chopper could not be ascertained, the recovery of the said chopper cannot be relied upon.
  • 31. A failure by the serologist to detect the origin of the blood due to disintegration of the serum does not mean that the blood stuck on the axe could not have been human blood at all. Sometimes it is possible, either because the stain is insufficient in itself, or due to haematological changes and plasmatic coagulation, that a serologist may fail to detect the origin of the blood in question. However, in such a case, unless the doubt is of a reasonable dimension, which a judicially conscientious mind may entertain with some objectivity, no benefit can be claimed by the accused in this regard. Once the recovery is made in pursuance of a disclosure statement made by the accused, the matching or non-­matching of blood group(s) loses significance. (Vide Prabhu Babaji Navle v. State of Bombay [AIR 1956 SC 51 : 1956 Cri LJ 147] , Raghav Prapanna Tripathi v. State of U.P. [AIR 1963 SC 74 : (1963) 1 Cri LJ 70] , State of Rajasthan v. Teja Ram [(1999) 3 SCC 507 : 1999 SCC (Cri) 436] , Gura Singh v. State of Rajasthan [(2001) 2 SCC 205 : 2001 SCC (Cri) 323 : AIR 2001 SC 330 ], John Pandian v. State [(2010) 14 SCC 129 : (2011) 3 SCC (Cri) 550 ] and Sunil Clifford Daniel v. State of Punjab [(2012) 11 SCC 205 : (2013) 1 SCC (Cri) 438 ] .)”

Appreciation of Evidence of Experts
In Mayur v. State of Gujarat AIR 1983 SC 5 , the Supreme Court observed that the evidence of a doctor has to be appreciated like the evidence of any other witness and there is no irrebuttable presumption that a doctor is always a witness of truth. The medical expert’s opinion is not always final and binding (Awadhesh v. State of MP, AIR 1988 SC 1158) . In an appropriate case on a consideration of the nature of the injuries and other relevant evidence, the Court can come to its own conclusion, if the medical evidence is deficient (Brij Bhukhan v. State of U.P., AIR 1957 SC 474).

In practice, the investigating agencies and courts give very high importance to wound-certificates and post-mortem certificates. They are considered as an indispensable part in most criminal cases. Same is the case of evidence of Ballistic expert. Here also primacy is given to ocular evidence if it is found credible by the court, especially when the ocular evidence is supported by the wound certificate or post-motem report.

Sure-Science and Nuances of various Scientific Evidences

Besides expert opinion of doctors, scientific techniques now a days frequently adopted by our courts include technical expertise on ballistics, fingerprint matching, handwriting comparison, DNA testing, superimposition techniques etc. With regard to the gradation of acceptability of scientific evidence it is held in M.S. Vishwanatha Rao Vs. Rathnabai, 2015-154 AIC 371: 2015-3 Kant LJ 583 as under:

  • “Mere submission of a report by the handwriting expert is not enough. The author of the said report should have been examined by the plaintiff and  then only the defendant could have cross-examined him. In the hierarchy of expert’s evidence, the evidence of a handwriting expert is on the lower hierarchy. It is not a sure science like DNA test or finger print test. It is not the similarity which is relevant where the authenticity of signature or handwriting is in dispute, rather it is the dissimilarity which will have to be taken into consideration by evalulating the evidence of the expert.”

Evidence of a handwriting expert: The above view is taken in Alois Simon Parmar Vs. State of Gujarat, 2007-2 GCD 1606: 2007-16 GHJ 41, and observed that handwriting expert evidence is a weak piece of evidence. In Ravjappa v. Nilakanta Rao, AIR 1962 Mys 53, it is observed:

  • “In examining a disputed document, the true test is not the extent of the similarities observed when compared with genuine documents, as forged documents usually are good imitations of genuine documents, but the nature and extent of the dissimilarities noticed. It is these differences which expose the true character of the document in question.”

brain mapping test: While referring the legal effect of a report of brain mapping test it is pointed out in Ranjitsing Brahmajeetsing Sharma v. State of Maharashtra AIR 2005 SC 2277 , that the admissibility of a result of a scientific test will depend upon its authenticity, and that whether the brain mapping test is so developed that the report will have a probative value so as to enable a court to place reliance thereupon, is a matter which would require further consideration, if and when the materials in support thereof are placed before the court.
thumb impression Science of identifying thumb impression is an exact science and does not admit any mistake or doubt (Jaspal singh v. State of Punjab, AIR 1979 SC 1708). The evidence of finger impression is admissible, but the person giving opinion must be an expert. The court has the liberty to accept or reject the opinion of the expert. The court must satisfy itself about the correctness of the conclusions by comparisons of the prints; it cannot be laid down as a rule of law that it is unsafe to have conviction on the uncorroborated testimony of a finger print expert. The SC held that it would be highly unsafe to convict on a capital charge without any independent corroboration of the opinion of the finger print experts (Mahmood v. State of UP, AIR 1976 SC 69).
footprints: Section 45 does not include footprints within the ambit of, as it does the finger print impressions. But, this omission, the evidence of the footprint expert has been admitted with the qualification that there should be other evidence to bring home the charge to the accused. The Supreme Court in Pritam Singh v. State of Punjab observed as under:

  • “The science of identification of foot-prints is no doubt a rudimentary science and not much reliance can be placed on the result of such identification. The track evidence, however, can be relied upon as a circumstance which, along with other circumstances, would point to the identity of the culprit though by itself it would not be enough to carry conviction in the minds of the Court.”

Evidence of tracker dog: Evidence of tracker dog is of little importance. No adverse inference can be drawn against the prosecution simply bvecuae the tracker was not examined by the prosecutor. In Abdul Razak v. State of Maharashtra AIR 1970 SC 283; the Supreme Court has expressed the opinion that in the present state of scientific knowledge, evidence of dog tracking, even if admissible, is not ordinarily of much weight.
superimposition of the skull: When the serologist who superimposed the skull of the deceased, opined that it was of an adult human female of certain age, and the same corroborated other evidences, it was sufficient to establish the identity of the deceased (State of Karnataka v. Bhoja Poojari, (1997) 11 SCC 537). If the report of the serologist corroborates other evidences, the court can believe it.
Ossification test: Ossification test is used to determine the age of a person. In Ram Deo Chauhan v. State of Assam, the Supreme Court held that ossification test is not conclusive. Positive evidence furnished by birth register, by members of the family, with regard to the age, will have preference over the opinion of the doctor; but if the evidence is wholly unsatisfactory, and if the ossification test in the case is complete, such test can be accepted as a surer ground for determination of age 23 . If the entry in the school register does not appear to be genuine, the medical evidence will prevail over it.

DNA Test: Scientific Proof Must Prevail Over ‘Conclusive Proof’.

It is observed in Pantangi Balarama Venkata Ganesh v. State of Andhra Pradesh 2003 Crl LJ 4508 , that DNA test is a ‘perfect science’. In K. Perumal v. S. Shakiladevi 2019 Cr LJ 1189, it is observed that DNA test only supplements oral evidence though it is ‘a strong piece of evidence’.

Nandlal Wasudeo Badwaik Vs. Lata Nandlal Badwaik, AIR 2014 SC 932 (Chandramauli Kr. Prasad, Jagdish Singh Khehar) is a very important decision which changed the concept of law on ‘conclusive presumption’.  It is held as under:

  • “17. We may remember that Section 112 of the Evidence Act was enacted at a time when the modern scientific advancement and DNA test were not even in contemplation of the Legislature. The result of DNA test is said to be scientifically accurate. Although Section 112 raises a presumption of conclusive proof on satisfaction of the conditions enumerated therein but the same is rebuttable. The presumption may afford legitimate means of arriving at an affirmative legal conclusion. While the truth or fact is known, in our opinion, there is no need or room for any presumption. Where there is evidence to the contrary, the presumption is rebuttable and must yield to proof. Interest of justice is best served by ascertaining the truth and the court should be furnished with the best available science and may not be left to bank upon presumptions, unless science has no answer to the facts in issue. In our opinion, when there is a conflict between a conclusive proof envisaged under law and a proof based on scientific advancement accepted by the world community to be correct, the latter must prevail over the former.”

Narcoanalysis: No Guarantee, Truthful; Scope for Error in Polygraph Examination

In Selvi Vs. State of Karnataka, AIR 2010 SC 1974, the Hon’ble Supreme Court, had clarified as under:

  • “210. Earlier in this judgment, we had surveyed some foreign judicial precedents dealing with each of the tests in question. A common concern expressed with regard to each of these techniques was the questionable reliability of the results generated by them. In respect of the narcoanalysis technique, it was observed that there is no guarantee that the drug- induced revelations will be truthful. Furthermore, empirical studies have shown that during the hypnotic stage, individuals are prone to suggestibility and there is a good chance that false results could lead to a finding of guilt or innocence. As far as polygraph examination is concerned, though there are some studies showing improvements in the accuracy of results with advancement in technology, there is always scope for error on account of several factors. Objections can be raised about the qualifications of the examiner, the physical conditions under which the test was conducted, the manner in which questions were framed and the possible use of ‘countermeasures’ by the test subject. A significant criticism of polygraphy is that sometimes the physiological responses triggered by feelings such as anxiety and fear could be misread as those triggered by deception. Similarly, with the Waves test there are inherent limitations such as the subject having had ‘prior exposure’ to the ‘probes’ which are used as stimuli. Furthermore, this technique has not been the focus of rigorous independent studies. The questionable scientific reliability of these techniques comes into conflict with the standard of proof ‘beyond reasonable doubt’ which is an essential feature of criminal trials.”
  • “223. In light of these conclusions, we hold that no individual should be forcibly subjected to any of the techniques in question, whether in the context of investigation in criminal cases or otherwise. Doing so would amount to an unwarranted intrusion into personal liberty. However, we do leave room for the voluntary administration of the impugned techniques in the context of criminal justice, provided that certain safeguards are in place. Even when the subject has given consent to undergo any of these tests, the test results by themselves cannot be admitted as evidence because the subject does not exercise conscious control over the responses during the administration of the test. However, any information or material that is subsequently discovered with the help of voluntary administered test results can be admitted, in accordance with Section 27 of the Evidence Act, 1872. The National Human Rights Commission had published ‘Guidelines for the Administration of Polygraph Test (Lie Detector Test) on an Accused’ in 2000. These guidelines should be strictly adhered to and similar safeguards should be adopted for conducting the ‘Narcoanalysis technique’ and the ‘Brain Electrical Activation Profile’ test. The text of these guidelines has been reproduced below:
  •  (i) No Lie Detector Tests should be administered except  on the basis of consent of the accused. An option  should be given to the accused whether he wishes  to avail such test.
  • (ii) If the accused volunteers for a Lie Detector Test, he  should be given access to a lawyer and the physical,  emotional and legal implication of such a test  should be explained to him by the police and his  lawyer.
  • (iii) The consent should be recorded before a Judicial Magistrate.  
  • (iv) During the hearing before the Magistrate, the  person alleged to have agreed should be duly  represented by a lawyer.
  • (v) At the hearing, the person in question should also  be told in clear terms that the statement that is  made shall not be a ‘confessional’ statement to the  Magistrate but will have the status of a statement  made to the police.
  • (vi) The Magistrate shall consider all factors relating to  the detention including the length of detention and the nature of the interrogation.
  • (vii) The actual recording of the Lie Detector Test shall  be done by an independent agency (such as a  hospital) and conducted in the presence of a lawyer.
  • (viii) A full medical and factual narration of the manner  of the information received must be taken on record.”

Material Data are to be Placed by the Expert to Enlighten the Court

In Pattu Rajan Vs. State of Tamil Nadu, AIR 2019 SC 1674, it is observed that it is the duty of an expert witness to assist the Court effectively by furnishing it with the relevant report based on his expertise along with his reasons, so that the Court may form its independent judgment by assessing such materials and reasons furnished by the expert for coming to an appropriate conclusion. It was also pointed out in this case that the opinion evidence is only advisory in nature, and the Court is not bound by the evidence of the experts.[2]

If direct evidence of the witnesses to the occurrence is satisfactory and reliable, it cannot be rejected on hypothetical medical evidence. [3] The court does not accept the subjective result arrived at by an expert without satisfying itself as to the material data evaluated or analysed by the expert. All materials inclusive of the data are to be placed first by the expert to enlighten the court on the technical aspects; and, then the he has to satisfy the court the conclusion arrived at. In Dhirajbhai Gorakhbhai Nayak v. State of Gujarat, (2003) 9 SCC 322, the Supreme Court held as under:

  • “Only in respect of Injury 1, there appears to be some confusion but that does not dilute the prosecution evidence. It would be erroneous to accord undue primacy to the hypothetical answers of medical witnesses to exclude the eyewitnesses’ account, which has to be tested independently and not treated as ‘variable’ keeping in view the medical evidence as ‘constant’.”

Similarly in Krishnan v. State (2003) 7 SCC 56 it was held as under:

  • “If the ocular evidence was cogent, credible and trustworthy, minor variance, if any, with the medical evidence pointing to alternative probabilities cannot be accepted as conclusive.”

Post-Mortem Report is not a Substantive Evidence

Post-mortem report or Wound Certificate is not a substantive evidence.[4] Unless the medical officer who conducted the post-mortem examination is examined in court, the post-mortem report cannot be used as substantive evidence. In Vadugu Chanti Babu v. State of A.P. (2002) 6 scc 547 it is observed that a stray statement of the doctor -cross-exam- not a conclusive opinion; but it is only a possibility.

Appreciation of Evidence is Both an Art and a Science

Once the expert’s opinion is accepted, it becomes the opinion of the court.  When there is stark conflict between medical and oral evidence, and oral evidence is found to be creditworthy, oral evidence is preferred. Minor contradictions do not weigh importance, and evidence of eyewitnesses is not thrown out on the ground of alleged (minor) inconsistency. Where medical evidence completely rules out the oral evidence, usually it used to discredit the eyewitnesses. Seldom medical evidence as such is relied upon by the courts, neglecting the oral evidence.

R. Basant, J., in Basheer Vs. Mahasakthi Enterprises – Ker LT 2005-3 163: 2005-1 Mad LJ 965, held as under:

  • “The appreciation of evidence is both an art and a science. All relevant inputs have to be taken into consideration for the Court to answer a disputed question of fact. Each circumstance including the opinion tendered by an expert must be taken into consideration. All the relevant inputs must be placed in the crucible. But the result of such appreciation must stem from prudence, reasonableness and intelligence of the Court. The knowledge of men and matters of the Court would be crucial. The knowledge of the court of common course of events and natural and probable behaviour of human beings will be vital. The yardsticks of a reasonably prudent mind have to be accepted. All relevant circumstances must go into the decision making. When the evidence is sifted, weighed, tested, analysed and evaluated, no one piece of evidence can be said to overrule the others unless such evidence be clinching, convincing and beyond doubt.”

With regard to the disputes as to the handwriting, it is pointed out in this decision that it is possible for a person to deliberately masquerade his handwriting to mislead others. Natural variations are all possible between standard writings and the disputed writings. Totality of circumstances has to be taken into consideration and no Court can decide the disputed questions sitting in the island of the opinion tendered by the handwriting expert.  With regard to the opinion of a hand-writing expert it is observed further as under:

  • “It is by now trite that the science of identification of handwriting is not a ‘perfect’ science and the opinion has to rely on subjective as well as objective observations and inferences drawn. As distinguished from scientific evidence like finger print etc., the science of identification of handwriting cannot be said to be absolutely fool-proof and cent-percent reliable.”

No Presumption of Truth

There is no presumption of truth as to the scientific evidence. It is also appreciated like the evidence of any other witness. The result of analysis and probabilities expressed by the experts are not accepted by the courts as conclusive evidence; because, they are not always final and binding upon the court, and the court can come to its own conclusion.

But, at the same time the courts cannot overlook the scientific evidence in toto. In Gajraj Vs. State (NCT) of Delhi, 2011-10 SCC 675, the Apex Court observed that the IEMI number of mobile phone (sim) registered in the name of a person being evidence of a conclusive nature, it cannot be discarded on the basis of minor discrepancies especially when there is serious discrepancy in oral evidence.  

Appreciation of Evidence of Experts

In Mayur v. State of Gujarat, AIR 1983 SC 5 the Supreme Court observed that the evidence of a doctor has to be appreciated like the evidence of any other witness and there is no irrebuttable presumption that a doctor is always a witness of truth.  The medical expert’s opinion is not always final and binding.[5] In an appropriate case on a consideration of the nature of the injuries and other relevant evidence, the Court can come to its own conclusion, if the medical evidence is deficient.[6]

Where the opinion of a medical witness is contradicted by another medical witness both of whom are equally competent to form an opinion, the court should normally accept the evidence of the medical witness whose evidence is corroborated by direct evidence;[7] and whose testimony accords with the prosecution version.[8]

Impact of Scientific Evidence

Scientific evidence by itself does not prove or disprove a case.[9] The general rule that is followed by our courts is that unless the scientific evidence completely rules out the veracity of oral evidence, otherwise reliable, cannot be rejected.[10] At the same time, where there is glaring conflict between medical and oral evidence, the prosecution case must fail.[11]

Therefore, medical opinion alone will not be sufficient to find guilt of an accused. The courts give weight to the opinion of doctors as to whether the injuries are Anti-mortem or Post-mortem, the probable weapon used in causing injuries, the effect of injuries, consequences of injuries, whether they are sufficient in the ordinary course of nature to cause death, the duration of injuries and the probable time of death, cause of death, plea of unsoundness of mind, determination of age etc. When an expert gives evidence after conducting post-mortem examination or examination of the injuries he is also a ‘witness of fact’ and his evidence stands also as an independent testimony quite apart from the ‘opinion evidence’.

However, the opinion of a medical witness is not taken as the last word by the courts. They are to be analysed and tested by the court. If there are different opinions, the court would adopt the view which is more objective or probable.

Undue primacy will not be given to the hypothetical answers of medical witnesses to exclude the eye witnesses. The courts will take note of the size and dimension of injuries said to be caused by a particular weapon and decide on questions relating to the same. Though account of eyewitnesses must prevail, it is not a universal principle; it is to be used in conjunction with other circumstances. The Supreme Court in Madan Gopal Kakkad v. Naval Dubey,  (1992) 3 SCC 204 : 1992 SCC (Cri) 598  held: “34. A medical witness called in as an expert to assist the court is not a witness of fact and the evidence given by the medical officer is really of an advisory character given on the basis of the symptoms found on examination. The expert witness is expected to put before the court all materials inclusive of the data which induced him to come to the conclusion and enlighten the court on the technical aspect of the case by explaining the terms of science so that the court although, not an expert may form its own judgement on those materials after giving due regard to the expert’s opinion because once the expert’s opinion is accepted, it is not the opinion of the medical officer but of the court.”

Medical Evidence Totally Inconsistent With Direct Evidence, Effect

If the evidence of the witness for the prosecution is totally inconsistent with the medical evidence, or where there is a glaring inconsistency between the direct evidence and the medical evidence, it will stand as a fundamental defect in the prosecution case and it is sufficient to discredit the entire case. [12] 

Where the opinion of the doctor is that the assailant shot from a distance of four feet, and the oral evidence show the distance as 18 or 20 feet from the deceased it will be held as a serious contradiction requires acquittal of the accused. (State of U.P. v. Ram Bahadur Singh, (2004) 9 SCC 310.

But, if the inconsistency is reasonably explained the expert evidence will be ignored. When variances between the oral and medical evidence are minor, credible and acceptable oral evidence can be given primacy over the other. Oral evidence has to get primacy since medical evidence is basically opinionative. The medical evidence adduced by prosecution has corroborative value since it supports why the eye-witnesses should not be disbelieved.

In Purshottom v. State of M.P., AIR 1980 SC 1873 the prosecution evidence showed infliction of three separate blows to the deceased. The medical officer who conducted the post-mortem examination found only one wound. According to him the wound found on the deceased could not have been the result of two simultaneous blows. It was found that it was extremely improbable, if not altogether impossible that three blows simultaneously given by three different persons from different directions with sharp edged weapons would land with such precision and exactitude so as to cause a single wound of such a clear cut margins and such dimensions and other characteristics as those of the external wound found by medical officer on the head of the deceased. The Supreme Court held that the version of the prosecution witnesses with regard to this vital fact was inherently improbable and intrinsically incredible. The ocular account of the occurrence was held falsified by the medical evidence. The accused were acquitted.

Amar Singh v. State of Punjab, AIR 1987 SC 826, is a similar case to Purshottom v. State of M.P. , mentioned above. In this case the prosecution witness stated that all the accused were armed with deadly weapons viz. Sua Barchi, Kulhari (axe), Dang (Cudgel) and Kirpan, and gave repeated blows with their respective weapons to the deceased and many of the blows fell on the ribs, and abdomen of the deceased, but in the post-mortem examination no injury was found on the ribs and abdomen of the deceased, not a single incised wound was found on the body of the deceased, and only abrasions, confusions and fractures were found, it was held that if the oral evidence were to be accepted there would be incised wounds all over the body of the deceased. Thus, there was apparent irreconcilable inconsistency between the oral and the medical evidence. The Supreme Court acquitted all the accused charged for murder.

Duty of the Prosecution to Prove Use of Weapon by Expert Evidence

The Supreme Court has held in Gurmej Singh v. State of Punjab, AIR 1992 SC 214 that the mere omission to elicit opinion of the medical officer in the witness box whether a particular injury was possible by the weapon of offence by showing weapon to the witness does not make difference where ocular testimony is acceptable and further corroborated by the first information report. 

In a case where death is due to injuries or wounds caused by a lethal weapon, it is always the duty of the prosecution to prove by expert evidence that it was likely or at least possible for the injuries to have been caused with the weapon with which and in the manner in which they are alleged to have been caused. (Mohinder Singh v. State, AIR 1953 SC 415; 1953 Cr.L.J. 1761).

In that case it was found doubtful whether the injuries which were attributed to the accused were caused by a gun or a rifle. The Supreme Court held that it was only by the evidence of a duly qualified expert that it could have been ascertained whether the injuries attributed to the accused were caused by a gun or a rifle and such evidence alone could settle the controversy as to whether they could possibly have been caused by a fire arm used at such a close range as was suggested in the evidence.

The principles laid down by the Hon’ble Supreme Court that the weapon of offence recovered in a case should be shown to an expert and he should be asked to say whether the injuries found on the deceased could be caused with that weapon has no application to cases where the alleged weapon of offence has not been recovered. (Jai Dev v. State of Punjab, AIR 1963 SC 612: 1963(1) Cr. L.J. 495).

 In Ishwar Singh v. State of U.P.,AIR 1976 SC 2423 (See also Kartarey v. State of UP, AIR 1976 SC 76: 1976 Cr.L.J. 13), the weapons were not shown to the medical officer who could have deposed which injury was caused by which weapon. The conviction of the accused was set aside by the Supreme Court and observed:

  • “It is the duty of the prosecution, and no less of the Court, to   see that the alleged weapon of the offence, if available, is  shown to the medical witness and his opinion invited as to  whether all or any of the injuries on the victim could be caused  with that weapon. Failure to do so may sometimes, cause aberration in the course of justice.”

But, where the medical evidence is clear, failure to produce weapon of offence would not negate the medical evidence (B.V. Danny Mao v. State, 1989 Cr LJ 226 (Gauh).

In Maghar Singh v. State: of Punjab, (1987) 2 SCC 642 the medical officer stated that the injuries found on the body of the deceased could be the result of either two shots or even more than two shots, but the evidence of eyewitnesses clearly showed that there were two shots. The Supreme Court held that there was no inconsistency between the medical evidence and the ocular evidence and the inconsistency deposed by the medical officer was merely a probability and it was not fatal to the prosecution case.

Use of Treatises

By the peculiar nature of scientific evidence, the court, in appraisal of such evidence, has power to refer to treatises of eminent authors acquainted with such matters.[13]

The Supreme Court requires that whenever it is intended to place reliance on a particular view taken by authors of book of Medical-jurisprudence, the said view must be put to the doctor to assess how far the view taken by the experts apply to the facts of the particular case.[14] Where conflicting views have been expressed in different books on Medical Jurisprudence, the conflict can be resolved by preferring the more specialised book on the subject.[15]


Courts always give due importance to the opinion of the experts. But, the expert-evidence is not a substantive evidence; and it is generally used as a piece of evidence for corroboration or for countering veracity of oral evidence. The evidence of an expert only aids and helps the Court as an advisory material.  The expert being not a witness of fact, his opinion is to be analysed objectively by the court. In this process, a Court is the expert of experts.

[1] Binder Munda v. State, 1992 Cr.L.J. 3508 Ori. (DB)

[2] The State (Delhi Administration) v. Pali Ram ,(1979) 2 SCC 158;

State of H.P. v. Jai Lal & Ors ., (1999) 7 SCC280;

Baso Prasad and Ors. v. State of Bihar , (2006) 13 SCC 65;

Malay Kumar Ganguly v. Dr. Sukumar Mukherjee, (2010) 2 SCC (Cri) 299.

[3] Solanki ChimanbhaiUkabhai v. State of Gujarat, AIR 1983 SC 484

Punjab Singh v. State of Haryana. AIR 1984 SC 1233

See also: Arjun v. State of Rajasthan, AIR 1995 SC 2507

[4] Mohan Singh v. Emperor, AIR 1925 All. 413 (DB).

State v. Rakshpal Singh, AIR 1953 All. 520;

Ram Pratap v. State, 1967 All.W.R. (H.C.) 395;

Ram Balak Singh v. State, AIR 1964 Pat. 62(DB);

Mellor v. Walnesley, 1905, 2Ch. 164 (CA);

Hadi Kisani v. State, AIR 1966 Orissa 21

Gofur Sheikh v. State, 1984 Cr.L.J. 559 (Cal);

Bhanda Gorh v. State of Assam, 1984 Cr.L.J.217 (Gau);

Jagdeo Singh v. State, 1979 Cr.L.J.236 (All);  

K. Pratap Reddy v. State of A.P., 1985 Cr.L.J.1446.

[5] Awadhesh v. State of MP  AIR 1988 SC 1158

[6] Brij Bhukhan v. State of U.P., AIR 1957 SC 474

[7] Piara Singh v. State of Punjab, AIR 1977 SC 2274,

[8] Makhan v. State of Gujarat, AIR 1971 SC 1797

[9] Stephen Seneviratne v. Kind, AIR 1936 P.C. 289,

Anant Chintaman Lagu v. State of Bombay, AIR 1960 C 500

[10] Vahula Bhusan v.State of Tamil Nadu, (1989) 1 SCJ 255,

State of U.P. v. Krishna Gopal, AIR 1988 SC 2154,

Dharamvir v. State, 1989 All. L.J. 454,

Awadhesh v. State of M.P. AIR 1988 SC 1158.

[11] Awadhesh v. State of M.P., AIR 1988 SC 1158,

Mohd. Habib v. State, 1988 CC Cases 401.

[12] Ram Narain v. State of Punjab. AIR 1975 SC 1727

Amar Singh v. State of Punjab. AIR 1987 SC 826,

Piara Singh v. State of Punjab, AIR 1977 SC 2274.

[13] MamjeePandey v. State of Bihar, 1989 Cr.L.J. (NOC) 186 (Pat.)

[14] Kusa v. State of Orissa, AIR 1980 SC 559,

Bhagwandas v. State of  Rajasthan, AIR 1957 SC 589,

Sunder Lal v. State of M.P., AIR 1954 SC 28,

Pratap Misra v. State of Orissa, AIR 1977 SC 1307.

[15] Mahendra Manilal Nanavati v. Sushila Mahendra Nanavati, AIR 1965 SC 364

Read in this cluster (Click on the topic):

Civil Suits: Procedure & Principles

Evidence Act


Contract Act




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