OPINION EVIDENCE

CONTENTS

1.0 Introduction

2.0 Objectives

• Main Content
• Definition of Opinion Evidence
• Fundamental Principles of Witness Evidence
• Expert Opinion
• Statutory Provisions
• Other Instances of Opinion Evidence
• Competency of an Expert or a Specialist
• Matters of Science and Art

4.0 Conclusion

5.0 Summary

6.0 Tutor Marked Assignment

7.0 Reference/Further Reading

 INTRODUCTION

The two words that feature prominently in the Law of Evidence are “proof” and “evidence”. Evidence is a means but proof or disproof is the end product. What require proof or disproof are facts. A fact is something that actually exists, an aspect of reality, an actual or alleged event or circumstance as distinct from its legal effect, consequence or interpretation. On the other hand, opinion evidence is a testimony based on one’s belief or idea rather than a direct knowledge of the facts or issue. The witness’s opinion is usually excluded from evidence.

In this unit, you shall learn about opinion evidence, the reasons for its exclusion and its exceptions. You will be empowered to boldly make your own reasoned decision for or against the admissibility of opinion evidence.

 OBJECTIVES

At the end of the study in this unit, the students should be able to understand what is meant by Opinion Evidence and identify the circumstances in which opinion evidence is generally admissible. Students should also be able to rationalize the basis on which opinion evidence has been given and admitted or rejected and what is meant by expert witnesses.

MAIN CONTENTS

• Definition of Opinion Evidence

Opinion Evidence or Testimony as the Black’s Law Dictionary 5^th Edition put it means the evidence of what the witness thinks, believes, or infers in regard to facts in dispute, as distinguished from his personal knowledge of the facts themselves.

It has been asserted that generally, the rules of evidence ordinarily do not permit a witness to testify as to opinions or conclusions except in certain circumstances and these are the exceptions to the general rule. One of such situation is the calling of ‘’Expert Witness’’.

Expert witnesses are those who by virtue of their education and experience have become knowledgeable [expert] and authority in their area of profession, calling or vocation whether it is in the field of art, humanities or science.

• Fundamental Principle of Witness Evidence

The purpose of calling a witness is to elicit from him or her evidence of facts which he or she has perceived by means of his or her senses. That is to say; What he or she saw with the eyes; What he or she tasted with the tongue.; How he or she felt; What he or she heard with the ears and What he or she smelt with the nose.

Opinion evidence is neither of the above. Rather it as an inference drawn from facts. But this is a function of the judge not of a witness – to make inference from or interpret facts in order to arrive at a verdict. Hence, generally a witness is not allowed to engage in inference

• drawing which is a judicial function or to testify about opinion rather than about facts

However, there are cases where the judge lacks the necessary experience to draw competently, appropriate inference from the facts that emerge from the proceeding. The court then allows someone with necessary expertise to do so. The purpose is to avail the court with experts opinion about facts to assist it in reaching a correct verdict.

An expert opinion may be received, therefore in evidence if it relates to a technical or scientific matter in which the competency to form an opinion cannot be acquired except by  a course of special study or experience. Arts, science, trade, handwriting, banking or foreign law confers such competence through a special course of study. Should any question of competency in any of these fields arise, an expert testimony expressing his or her reasoned opinion is admissible. Otherwise such evidence is inadmissible. The reasons for exclusion of opinion evidence are that, it is:

• not a technical and not a scientific matter
• not susceptible to empirical proof or disproof
• a usurpation of the functions of the judge,
• being an inference drawn from an interpretation
• formed from  materials  that  would  normally be excluded   from under the hearsay

The exclusion of opinion evidence has been criticized on the ground that it is capable of depriving the court of most valuable testimony. Critics argue that opinion evidence ought to be admissible, leaving the judge in each case, to decide what weight to attach to it.

SELF ASSESSMENT EXERCISE

Compare the prejudicial and the probative values of opinion evidence.

• Expert Opinion

An expert may be required to give evidence of:

1. A fact or facts which he perceived with one of his or her five senses,
2. His or her opinion on a matter in which the court considers him or her an expert.

The first is direct evidence. In this sense the expert is an ordinary witness to which no special rules apply.

The second is scientific or technical – a matter which involves knowledge of a technicality – like handwriting, foreign law etc. In this case of opinion evidence, special rules apply.

 The test of admissibility of expert evidence of opinion:

The admissibility of expert opinion depends on the following:

• The court’s competence to determine the matter without assistance
• The qualification of the expert – whether he or she is a member of a profession; his/her formal qualifications – doctor, engineer, pathologist, chemist, etc?

Formal qualification is important but it is not a condition precedent. For example, a solicitor may qualify as a handwriting expert if it was his hobby to study handwriting. Non-expert opinion is frequently accepted e.g. in areas of identification or value. In R.V. Davies (1967), the accused was charged with driving a motor vehicle while intoxicated, he was unfit to drive. A non-expert witness was called to give evidence as to his drunken state or condition and he spoke as to the opinion he formed of the condition of the accused. The court, in regard to the non-expert witness, expressed the following opinion:

1. That the non-expert witness might state his opinion, whether the accused had taken liquor or not , but must give the facts upon which he relied in forming his opinion,
2. Not being an expert, he was not entitled to say whether the accused was fit or unfit to drive the vehicle. That was a matter for the trial court to decide, not the opinion of non- experts or ordinary witness

• The opinion of person other than experts may be admissible in regard to the state or condition of a person or thing, other than his/her mental condition. Examples are:-
  1. Where a fact in issue is the opinion of a person e.g. opinion of another of libel, who pleads fair comment or the opinion of a witness to whom a false pretence was addressed or the opinion of a person defrauded that what the fraudster said was true
  2. Personal opinion or belief about facts in issue which is based on grounds of experience. Such evidence has been admissible to prove identity, handwriting, age, insanity, intoxication etc. It has even been used to prove the speed of a vehicle, the value of articles and the affection between persons, where more direct  and  positive  evidence are not available
  3. In interlocutory proceedings, a deponent may state his opinion and the ground of its foundation

Competency of an expert or specialist

The Evidence Act does not give us any guideline on how to identify an expert with any degree of certainty.

An expert is a person especially skilled in the field of foreign law, native law and Custom, of science or art, handwriting and finger print analysis. His or her competency is for the judge to decide. Whether or not he or she acquired knowledge professionally goes to weight not admissibility. The test of an experts’ relevance is whether he is specially skilled on the particular field in question.

When called as an expert witness, you must first state your qualification, experience, training, nature and duty or your office relative to your field so as to satisfy the court that you are an expert on the subject in which you are about to testify as well as justify the reception of your evidence as relevant evidence.

It has to be noted, however that not only the general nature but also the precise character of the question upon which the expert evidence is required, have to be taken into account when deciding whether the qualifications of a person entitles him to be regarded as a competent expert: Ajani v the Comptroller of Customs (1954).

The credit or knowledge of the expert can be impeached by such evidence as bias or inconsistent opinions. An expert cannot form an opinion based on materials which are not before the court nor give opinion as to the legal or general merits of a case, except the expert is so asked. Such a situation arises where he or she is also a witness of the relevant facts and the issue in substantially one of science or skill.

As an expert, you may refer to textbooks and refresh your memory, correct or confirm your opinion and may be cross – examined.

• Statutory Provisions
• The Evidence Act

Section 68

• When the court has to form an opinion upon a point of foreign law, native law or custom or a science or art or as to identity of handwriting or finger print impressions, the opinions upon that point of persons especially skilled in such foreign law, customary law or custom, or science or art or in questions as to identify of handwriting or finger impressions are =
• Persons so specially skilled as mentioned in sub-section (1) of this section are called experts.

Section 67

The fact that any person is of the opinion that a fact in issue or relevant to the issue does or does not exist is irrelevant to the existence of such a fact, except as provided in section 68 to 76 of the Act.

• Exceptions

Although the basic principle is that a witness should testify about facts, experts may be allowed to give evidence of:

1. Facts which themselves require to be proved by admissible evidence
2. Opinion based on the facts of the particular case

Before giving opinion evidence in a trial proceeding, the expert must first lay a foundation. The foundation refers to the ground or reasoning upon which the opinion is founded.

The court will dispense with expert evidence where it is capable of forming its opinion as the expert e.g. Disputed points of etiquette or morality, not being professional etiquette or morality. The court sitting with Assessors as in admiralty cases which involve questions of nautical skills is just as capable of forming the opinion as an expert.

3. Experts may refer to information relating to their field of expertise that has come to them as a second hand (this rule is an exception to the hearsay rule)
4. When giving evidence as an expert, you may refer to articles, journals, and other materials (published or unpublished) in support of your opinion

Look at some illustrations or circumstances when the courts have received opinion evidence from persons skilled but are non-professionals.

(a) Foreign law

AJANI V THE CONTROLLER OF CUSTOMS (1952) 14 WACA 39, the Judicial Committee of the Privy Council (JCPC) held that a banker was “specially skilled” to give opinions as to foreign law based on his experiences, position or status and duties relative to the subject matter.

BAILEY V RHODESIA CONSOLIDATED LTD (1910), a Reader in Roman – Dutch law of the Council of Legal Education was held to be an expert in Roman Dutch law.

(b). Native law and Customs

Customary law is the mirror of accepted usage. It is “the dynamic or living law of the indigenous people regulating their lives and transaction. It is organic in that it is not static. It is regulatory in that it controls the lives and transaction of the community subject to it. Customary law probably goes further and import justice to the lives of all those subject to it”. OKONKWO V. OKAGBUA (1994).

It is settled law that except where a rule of customary law has received judicial recognition, such rule is treated for purposes of proof as a matter of fact ADEGBOYEGA V. IGBINOSU (1969) I ALL NLR 1. Where the customary law is not judicially noticed, it may be proved by testimony, in court, of a witness acquainted with the particular law. Thus “in deciding questions of native law and custom, the opinions of native chiefs or other persons having special knowledge of the native law and custom and any book or manuscript recognised by the natives as a legal authority are relevant. Examples of such books, which judges have consulted, are:

• Ajisafe: Laws and Customs of the Yoruba
• Folarin: The Laws and Customs of Egba Land (See ADESEYE & ORS. V TAIWO (1956) 14 WACA 84)
• Ward Price: Memorandun of Land Tenure in Yoruba Province (ADEDIBU V ADEWOYIN & ANOR. (1951) 13 WACA 191)

Part of these books were written by persons of Yoruba origin and received  in support  of  the existence of certain Yoruba customs by the Supreme court in ADESEYE V. TAIWO AND SUBERU V. SUNMONU

The Evidence Act section 68 is not exhaustive of areas where an expert opinion may be sought. In SEISMOGRAPH SERVICES LTD V. OGBENI (1976)4 SC 85. P sued for nuisance and damage to his house from D’s exploration exercise. P called for an expert to testify that the damage was caused by the vibration from seismic operation. The trial Judge rejected it, saying the court was capable of making the relevant inference without resort to experts. On appeal, the Supreme Court said.

“We are unable to agree with the learned trial judge that the evidence of an expert is not absolutely necessary to prove damage alleged to be caused by the vibration radiating from seismic operations taking place within a reasonable distance from the property damaged. These are phenomena beyond the knowledge of the unscientific and untrained in  seismology and civil engineering”, (Per Obaseki, JSC).

• Other Instances of Opinion Evidence

There have been other specific subjects of expert evidence, namely:

1. Evidence as to identity

2.Handwriting

3. Other cases

4.Evidence of Identification

Evidence as to the identification of a person or a thing is an expression of opinion. Examples are evidence of:

• a person’s general resemblance to a photograph or a member of and identification parade.
• memory of goods stolen in comparison with actual goods recovered
• the age of a person
• Condition of a person or thing

You can give evidence as to the identification in appropriate cases as an expert or non- expert.

• Handwriting

Handwriting includes type-writing. When hand writing or type-writing is in dispute, a handwriting expert may compare a document proved to have been written by the person whose handwriting it is sought with the document in dispute. After carrying out such a comparison, the hand-writing expert may be called to give his or her opinion.

Sometimes, the court may ask the person whose handwriting is disputed to write in the presence of the court and the court may form its opinion with or without expert guidance.

Sometimes, the witness need not be a specialist or an expert in handwriting analysis. It suffices that he or she is one who:

• forms an opinion based on mental comparison,
• sees or has seen the person (whose handwriting it is sought to compare) write on the particular occasions or
• is conversant with his or her writing having seen letters assumed to be in his or her writing or
• having read some document purportedly written by the person whose handwriting is in dispute.
• is skilled or has given consideration attention and study to the subject. The courts have received opinion or expert evidences of handwriting from:
  • Police officer V. ONITIRI (1946) 12 WACA 58.
• (Solicitor who studied finger print for 10years V. SILVERLOCK (1894) 2 QB 766.
• Handwriting analysts who are trained specialists in the field
• Persons who are skilled in finger print impression analyses
• Others

The court may also admit evidence opinion in other exceptional cases. Examples are opinion evidence of:

• general reputation
• ones belief truthfully of what the accused said
• speed of a motor car
• Evidence of General Reputation and Opinion

Evidence of general reputation and opinion is irrelevant and generally not admissible. The reasons may be that:

• It is excluded by the hearsay rule (e.g. Evidence of a general reputation in a community)
• It is the function of the court, not of witness, to draw a conclusion from the facts proved. However, the court may admit it in the following exceptional cases
• To prove marriage (other than bigamy or divorce cases)
• To prove character
• To prove evidence of public right
• to support a branch of a family tree in pedigree cases
• To prove identity (e.g. identity of a legatee)

 Illustration

Jonah and Rebecca lived together for 4 years in Suleja. Their friends and neighbours believed that they are husband and wife. Rebecca has died. Jonah married Ms Titi. Much later, Jonah dies intestate.

The question for determination is who is or who are entitled to inherit.

There is no evidence that Jonah and Rebecca ever married. No marriage certificate, either. But they had four children while they lived together and their birth certificates showed that their parents – Jonah and Rebecca – were husband and wife.

If Jonah and Rebecca were not married, then the four children are illegitimate and cannot inherit. If they were, then the children would. The important question to be decided is whether Jonah and Rebecca were paramour lovers or husband and wife. In proof of this, there is no direct evidence but only evidence of friends and neighbour. Is this evidence receivable? Is there sufficient evidence upon which to assume that Jonah and Rebecca were married to each other?

The answer to both questions is YES, unless the contrary was clearly proved. Thus the rules of intestate succession, would apply as though Jonah and Rebecca had been duly married, Jonah having died without a Will. In case of divorce, however, marriage is not to  be assumed. It has to be strictly proved.

Although the evidence of general reputation is generally excluded and may in appropriate case be admissible to prove marriage, the court may refuse to admit the fact of cohabitation to found a presumption of marriage in the following cases.

• charge of Bigamy
• case of matrimonial proceedings e.g. divorce

In this type of case, the fact of marriage must be strictly proved.

• Expert Opinion

An expert opinion is evidence about a scientific, technical, or professional issue given by a person qualified to testify because of familiarity with the subject or special training in the field.

Experts must be skilled in their subject; it is immaterial how the skill is acquired. You may not, as a witness, be specially qualified; yet you may be an expert for a particular purpose. An example would be where you have a special knowledge acquired by study of materials that are relevant to a particular case.

The court would consider your qualifications, experience and nature of duties in order to determine your suitability as expert. The court is at liberty to declare that a certain area of knowledge (e.g. psychological autopsy of a deceased person) is insufficiently developed to be a topic on which expert evidence will be admissible.

SELF ASSESSMENT EXERCISE

1. Explain who may qualify as an expert

• New Dimensions of Matters of Science and Art

Matters of science and arts permit opinion of experts. The expression “science and arts” has been expanded beyond the well-established disciplines and fields of knowledge under the two heads. It covers almost any matter, which is the subject of special knowledge. The expansion of the scope is occasioned by the advancement in science and technology outside the knowledge of judges e.g. blurred boundary between the abnormal and the normal mental states. Thus, a medical witness may give evidence of conduct indicative of insanity. If he has had the accused under observation, he may state as an “expert” that his opinion is that the accused is sane or insane. But he must not be asked whether or not the Accused is insane.

• Psychiatrists and Psychologists: Persons so especially skilled are experts Sec 68(2) Evidence Act

The English courts have shown a readiness to receive psychiatrist or psychologist expert as to:

1. reliability of a confession (Ragship and others, (1991); Walker (1998) and O.Brian (2000 )these are foreign matters the Nigerian courts are unlikely to hold under Evidence Act 2011
2. the defect or  abnormalities  of  mind  to  impeach  the  credibility  of  the  witness  or witnesses or show that the patient is incapable of giving reliable evidence

At the same time, the court has been reluctant to allow expert opinion as to:

1. Mens rea – its existence or non-existence RV TURNER (1975) Q B 834. COMPARE LOWERY V QUEEN (1974)
2. Truthfulness of a witness or evidence MACKNANNEY V PINFIELD (1981), BROWNING (1995)
3. Ultimate Issue: ultimate issue is for the judge to decide and pronounce a verdict and expert opinion is irrelevant. Sometimes the judge allows it. Theodosi (1993); Stockwell (1993). These decisions are guides only and for purpose of argument bearing in mind the doctrine of judicial precedent

• Foreign Law

 Expert opinion as to foreign law may be given by a person, who in his/her profession is acquainted with such law.

 Customary law and Custom

The traditional rulers, chiefs, or other person having special knowledge of the Customary law and custom may testify as experts. The opinions are respected as those of experts and are admissible.

Furthermore matters of Customary law and Customs may be proved by reference to any book or manuscripts, which the indigenous people in the locality recognize as a legal authority.

 Facts bearing on Expert Opinion

When opinion evidence is admitted in evidence, facts which may otherwise be irrelevant become relevant and admissible of the support or are inconsistent with the  experts  opinion.

So far you have dealt with opinions of experts. There are occasions when opinions of non- experts are relevant to these, we may now turn;

• Opinion of non-experts Section 72

The opinion of non-experts may be admitted in proof of:

Opinion as to a handwriting may be given by a person who is acquainted with the handwriting or a signature of its author.

• Existence of general custom or right, including customs or rights common to any considerable class of persons.(section 73)

The Court would receive the opinion of non-expert who would be likely to know of the existed if it existed.

• Usages and tenets Section 74 - A non-expert opinion may be received as to:

1. usages and tenets of anybody of men or family
2. the constitution and government of any religious of charitable foundation

• the meaning of words or terms used in a particular  district  or particular  class of people
  • Non-expert opinion; it must be shown that the witness has special means of knowledge to the satisfaction of the court on the matter specified in (c) (i-iii)
• Relationship of one person to another: Section 75

A member of the family or other person who has special means of knowledge on the subject may volunteer opinion expressed by conduct.

A non-expert opinion is irrelevant as to marriage in cases of

• divorces or petition for
• petition for damages against adulterer
• Bigamy

 CONCLUSION

It is a fundamental principle of witness evidence that a witness should testify as to facts and not as to their opinions from facts. Opinions may be products of secondary evidence- hearsay. Opinion evidence, generally, is excluded from evidence. But where some thing has arisen, which is outside the experience of the court, opinion evidence becomes relevant and admissible. Thus expert opinion is receivable to prove foreign law and customary law and custom.

Similarly non expert opinion may be relevant and admissible to prove on handwriting, general custom or right, usages and tenets, constitution and government of a religious or charitable foundation, meaning of words or terms used in particular locality or  circumstance, and special relationship between one person and another. Facts  not otherwise relevant are relevant if they support or are inconsistent with an expert opinion and when the opinion of a living person is admissible, the ground on which such opinion is based are also admissible.

SUMMARY

In this unit, you learnt what opinion evidence is and the reasons for its exclusion from evidence. The evidence allows some exceptions to the rule, which you need to keep to the heart. You also learnt who may give an expert opinion. Any person subject to satisfying certain pre-conditioning may give opinion of foreign law, native law and  custom, handwriting (including typewriting) and fingerprint impression. You may note instances, where growth in science and technology has stretched the scope of expert opinion into  areas of psychiatrist and psychologist opinion. Examples are areas of reliability of a confession, credibility of a witness and reluctance of the court to yield grounds when it touches the existence or nonexistence of mens rea, truthfulness of witness(es) or evidence and the ultimate issues of which the court is competent.

TUTOR MARKED ASSIGNMENT

What is the fundamental principle of witness evidence and how has the hearsay rule been relaxed for expert witness.

REFERENCES/FURTHER READINGS

1. Allen and Gush (2004) Evidence, University of London Press.
2. Nwandialo F. (1999) 2nd Ed. Modern Nigerian Law of Evidence, Lagos University Press.
3. Evidence Act
4. AFE B. (2001 Law and Practice of Evidence in