# An Overview of Key Concepts in the Nigerian Law of Evidence
1. Electronically Generated Evidence
The admissibility of evidence generated by computers is a modern and important area of the law of evidence. In Nigeria, this is governed primarily by the Evidence Act 2011.
I. Admissibility of Documents from Data Apps (e.g., WhatsApp)
Documents produced by computers, including messages from applications like WhatsApp, are admissible in Nigerian courts. The main rule is found in Section 84(1) of the Evidence Act 2011, which states that a statement contained in a document produced by a computer shall be admissible as evidence of any fact stated in it, provided certain conditions are met.
These conditions are laid out in Section 84(2) of the Act. For a WhatsApp message printout to be admitted, the party tendering it must prove the following four things:
1. That the document (the printout) was produced by the computer during a period when the computer was used regularly to store or process information for the purposes of any activities regularly carried on over that period. For instance, it must be shown that the phone or computer used to access WhatsApp was in regular use.
2. That over that period, information of the kind contained in the statement was regularly supplied to the computer in the ordinary course of those activities. This means showing that sending and receiving messages was a normal function of the device.
3. That throughout the material part of that period, the computer was operating properly. If it was not, any malfunction must be shown not to have affected the production of the document or the accuracy of its contents.
4. That the information contained in the statement reproduces or is derived from information supplied to the computer in the ordinary course of those activities. In essence, the printout must be an accurate copy of the data that was on the device.
For example, if the prosecution wants to tender a WhatsApp conversation where the defendant admitted to a crime, they must satisfy the court that the phone from which the messages were retrieved was in regular and proper working order at the time the messages were sent and saved.
II. Proving the Computer was Used to Store Information
To prove the conditions listed in Section 84(2), a party must provide evidence. This can be done through the oral testimony of a witness. This witness does not need to be a computer expert. The law requires a person who has knowledge of the way the computer system works. This could be the owner of the phone who can testify that they use it for WhatsApp messaging every day and that it was working correctly. In a business context, an IT officer could testify about the regular use and proper functioning of the company’s computer network from which an email was retrieved. The key is that the witness can attest to the regularity and reliability of the device and the information-handling process.
III. The Issue of a Certificate (Section 84(4) and *Kubor v. Dickson*)
Section 84(4) of the Evidence Act provides an alternative way to prove the conditions of admissibility. Instead of calling a witness, a party can simply produce a certificate. This certificate must:
a) Identify the electronic document in question and describe how it was produced.
b) Give particulars of any device involved in the production of the document.
c) Deal with the conditions listed in Section 84(2).
d) Be signed by a person occupying a responsible position in relation to the operation of the relevant device or the management of the relevant activities.
The case of *Kubor v. Dickson* [2013] 4 NWLR (Pt. 1345) 534 is a very important Supreme Court decision on this point. In this case, the court clarified the law on admissibility of electronic evidence. It held that a party seeking to tender a computer-generated document *must* comply with the requirements of Section 84. The Supreme Court stated that this can be done in one of two ways:
1. By calling a witness to give oral evidence to show that the conditions in Section 84(2) have been met.
2. By tendering a certificate of authenticity in compliance with Section 84(4).
Failure to do either of these will render the electronically generated evidence inadmissible. So, if a party simply tries to tender a computer printout without either calling a witness to lay the foundation or producing the required certificate, the court is bound to reject it.
IV. Documents Retrieved from the Cloud
Cloud storage involves storing data on remote servers accessed via the internet. Documents retrieved from services like Google Drive or iCloud are also computer-generated evidence and must satisfy the conditions of Section 84. The ‘computer’ in this context would be the network of servers that make up the cloud service.
Proving the conditions can be more complex. A user who saved a document to the cloud can testify about their regular use of the service. However, to fully satisfy the conditions about the proper functioning of the computer system, it may be necessary to get a certificate under Section 84(4) from an appropriate person at the cloud service company (e.g., Google or Apple). This can present practical challenges, as such companies are often based abroad and may not be easily willing to provide such certificates for litigation in Nigeria. However, the legal requirement remains the same.
2. Corroboration
I. Conviction on Uncorroborated Evidence
As a general rule in Nigerian law, a court can convict an accused person based on the testimony of a single witness, provided the court is satisfied that the witness is credible and the evidence is sufficient to prove the case beyond reasonable doubt. Section 199 of the Evidence Act 2011 states that, except where it is otherwise provided in the Act, no particular number of witnesses shall be required for the proof of any fact. This means there is no general requirement for corroboration.
II. What Constitutes Corroboration?
Corroboration is evidence from an independent source that confirms another piece of evidence in a material particular. It is not just any evidence; it must be evidence that connects the accused person to the crime. The classic definition comes from the case of *R v. Baskerville* [1916] 2 KB 658, which is followed in Nigeria. The court stated that corroboration must be “independent testimony which affects the accused by connecting or tending to connect him with the crime. In other words, it must be evidence which implicates him, that is, which confirms in some material particular not only the evidence that the crime has been committed, but also that the prisoner committed it.” For example, if a witness testifies that the accused robbed them, evidence from another person who saw the accused running from the scene, or discovery of the stolen property in the accused’s possession, would be corroboration.
III. When is Corroboration Mandatory?
While corroboration is not generally required, there are specific instances where it is either required by statute or as a matter of judicial practice.
**Statutory Categories:**
* **Treason and Treasonable Felony:** Section 200 of the Evidence Act 2011 requires the testimony of at least two witnesses, or one witness with corroboration, for a conviction.
* **Perjury:** A person cannot be convicted of giving false evidence solely on the evidence of one witness as to the falsity of any statement (Section 201, Evidence Act 2011).
* **Exceeding Speed Limit:** Evidence from a single witness that a person exceeded a speed limit is not enough for a conviction unless it is corroborated (Section 202, Evidence Act 2011).
**Judicial Categories:**
* **Evidence of an Accomplice:** An accomplice is a person who participated in the crime. While a court *can* convict on the uncorroborated evidence of an accomplice, it is a rule of practice that the judge must warn himself of the danger of doing so because an accomplice may have a motive to lie (Section 198, Evidence Act 2011).
* **Evidence of a Child:** Where a child gives unsworn evidence, the accused cannot be convicted unless that evidence is corroborated by some other material evidence.
* **Sexual Offences:** It was previously a rule of practice for a judge to warn the jury that it is dangerous to convict on the uncorroborated evidence of the complainant in sexual offence cases. However, this mandatory warning has been criticised and is no longer a strict requirement. The modern approach is that the credibility of the witness is the key factor, although a judge would still exercise caution.
Other aspects like the demeanour of a witness (how they behave in court) can affect their credibility but do not amount to corroboration because demeanour is not independent evidence that connects the accused to the crime.
3. Estoppel and Burden of Proof
I. Forms of Estoppel
Estoppel is a rule of evidence that prevents a person from denying the truth of a statement they have previously made, or from denying a state of affairs that they have led another person to believe exists. Its main forms are:
1. **Estoppel by Record (or Res Judicata):** This prevents parties from re-litigating issues that have already been decided by a court of competent jurisdiction. The conditions are that the issue must be the same, the parties (or their privies) must be the same, and the earlier judgment must have been final and made by a court with jurisdiction.
2. **Estoppel by Deed:** This arises from a deed (a formal legal document). A person who is a party to a deed is stopped from denying the truth of the facts stated in it.
3. **Estoppel in Pais (by Conduct or Representation):** This is the most common form. It occurs where one person (the representor) makes a representation of fact to another person (the representee), who then acts on that representation to their detriment. The representor is then “estopped” from denying the truth of the representation. The conditions are: (a) a clear and unambiguous representation of fact; (b) the representor intended for it to be acted upon; (c) the representee acted on it; and (d) the representee suffered a detriment as a result.
II. Burden of Proof
The burden of proof has two main aspects: the legal burden and the evidential burden.
* **Legal Burden:** This is the overall burden of proving the case. In criminal law, Section 135(1) of the Evidence Act 2011 places the legal burden on the prosecution to prove the guilt of the accused beyond a reasonable doubt. This burden never shifts. This is the cornerstone of criminal justice.
* **Evidential Burden:** This is the burden of adducing enough evidence on a particular issue to make it a live issue in the trial. This burden can shift between the prosecution and the defence.
The defendant bears an evidential burden when raising certain defences. For example:
* **Alibi:** If the defendant claims he was somewhere else when the crime was committed, he has the evidential burden of introducing some evidence of the alibi. The legal burden remains on the prosecution to disprove the alibi beyond reasonable doubt.
* **Insanity:** Under the Criminal Code, every person is presumed to be of sound mind. If the defendant raises the defence of insanity, they bear the burden of proving it on the balance of probabilities. This is a rare instance where a legal burden is placed on the defendant.
Some statutes also place a legal burden on the defendant to prove specific facts, often called “reverse onus” clauses. For example, if a person is charged with being in possession of certain goods without a license, the law might require the defendant to prove that they have a license.
III. Tendering a Marriage Certificate
The question regarding the unavailability of a legal practitioner to tender a marriage certificate is confusingly worded. However, it seems to be about the procedure for admitting such a document. A marriage certificate issued by a marriage registry is a public document under the Evidence Act. Section 104 of the Act allows for certified true copies of public documents to be produced in proof of the contents of the public documents.
The established legal procedure is that a certified true copy of a public document is admissible from the bar, meaning a lawyer can tender it directly without calling a witness. If a legal practitioner is unavailable, another lawyer representing the party can tender it, or the party themselves if they are unrepresented. The unavailability of a specific lawyer does not make an otherwise admissible document inadmissible. The authenticity of a certified true copy of a public document is presumed under the law, and it does not require the testimony of its maker to be admitted.
4. Character, Opinion, and Similar Fact Evidence
Admissibility of Character Evidence
* **In Criminal Cases:** The general rule is that the prosecution cannot lead evidence of the accused’s bad character to show he was likely to have committed the offence. This is to avoid prejudice. However, the accused is free to adduce evidence of his own good character to suggest he is unlikely to have committed the crime. If the accused does this, or if the accused attacks the character of the prosecution witnesses, they lose this “shield,” and the prosecution may be permitted to lead evidence of their bad character in rebuttal (Section 82, Evidence Act 2011).
* **In Civil Cases:** Evidence of a party’s character is generally irrelevant and inadmissible. For example, in a breach of contract case, it is not relevant whether the defendant is generally an honest or dishonest person. An exception is where a person’s character is itself a fact in issue, such as in a defamation case where the claimant’s reputation is central to the proceedings.
Opinion Evidence
The general rule is that a witness must testify to facts they have perceived, not their opinion. However, there are two key exceptions:
1. **Non-Expert Opinion:** A layperson’s opinion is admissible if it is a way of conveying facts they personally perceived. Examples include opinions on the speed of a car, the age of a person, a person’s emotional state, or the identity of someone they know well.
2. **Expert Opinion:** Under Section 68 of the Evidence Act, when a court has to form an opinion on a point of foreign law, science or art, or as to the identity of handwriting or finger impressions, the opinions of persons specially skilled in such areas (experts) are relevant facts. For this evidence to be admissible, it must be shown that the field is one where expertise is required and that the witness is indeed an expert. The expert must also provide the basis for their opinion. The court, however, is not bound by the expert’s opinion and must evaluate it alongside all other evidence.
The Doctrine of Similar Fact Evidence
This doctrine, which originates from the case of *Makin v. Attorney-General for New South Wales* [1894] AC 57, governs the admissibility of evidence that a person has behaved in a similar way on other occasions. The general rule is that such evidence is inadmissible if its only purpose is to show that the accused has a disposition or tendency to commit a certain type of crime and is therefore likely to have committed the crime charged.
However, similar fact evidence is admissible if it is relevant for another purpose. It can be admitted if it tends to show:
* The identity of the offender.
* The intent of the offender.
* A system or pattern of behaviour.
* To rebut a defence of accident, mistake, or innocent association.
For example, if a man is charged with defrauding someone by using a very specific and unusual trick, evidence that he has used the exact same trick to defraud other people in the past would be admissible. This is not to show he is a fraudulent person, but to prove that the incident in question was not an accident and to identify him as the perpetrator, as the pattern of conduct is so unique.
References
* *Evidence Act* (2011) Laws of the Federation of Nigeria.
* *Criminal Code Act* (1990) Cap C38, Laws of the Federation of Nigeria.
* *Kubor v. Dickson* [2013] 4 NWLR (Pt. 1345) 534.
* *Makin v. Attorney-General for New South Wales* [1894] AC 57.
* *R v. Baskerville* [1916] 2 KB 658.
* *Woolmington v. DPP* [1935] AC 462.
