Similar Facts Evidence: When the Past is Relevant

If a man is charged with raping a woman in a hotel room, can the prosecution bring evidence that he committed the same act against three other women in hotel rooms in a similar manner over the past two years? The gut reaction of many students is: of course. That evidence makes him look like a serial offender. Why would the court not hear it?

The gut reaction is wrong. Evidence of past misconduct is one of the most carefully controlled areas in Nigerian evidence law. Bringing in evidence of what a person did before, simply to show they are the type of person who does such things, is exactly what the law prohibits. The accused is in court for what they did on this occasion, not for who they are as a person.

But there is a limit to that prohibition. Sometimes, past acts do more than paint a general picture of bad character. Sometimes they reveal a pattern so specific and so particular that they genuinely help the court decide whether the accused committed the act charged. When that is the case, similar facts evidence is admissible.

This article explains when Nigerian courts will admit similar facts evidence, what makes it genuinely probative rather than merely prejudicial, and how to distinguish it from inadmissible character evidence.

The Basic Rule: Bad Character Evidence is Inadmissible

Section 82(1) of the Evidence Act 2011 states the general rule clearly. Evidence of the fact that a defendant is of bad character is inadmissible in criminal proceedings. The law does not want courts convicting people because they are generally bad or because they have done bad things before. It wants courts convicting people because the evidence proves they committed the specific act charged.

The reasons for this rule go beyond fairness to the accused. There is also a risk of prejudice to the accuracy of the verdict. A court that knows an accused has a bad record is at risk of reasoning backwards: the accused is the kind of person who does this, therefore they probably did this. That reasoning is logically flawed, and allowing it risks convicting people not on the evidence of what they did but on the evidence of who they are.

When Similar Facts Evidence is Admissible

Section 12 of the Evidence Act 2011 is the primary provision for similar facts evidence. It provides that when a question arises whether an act was accidental or intentional, or was done with a particular knowledge or intent, the fact that such an act formed part of a series of similar occurrences, in each of which the person doing the act was concerned, is relevant.

Three elements must be satisfied for section 12 to apply.

First, there must be a specific issue in the case about intention, knowledge, or accident. If the accused admits the act but says it was accidental, or denies having the relevant knowledge, then the specific mental element is in issue. Similar past acts become relevant to resolve that specific question.

Second, the similar acts must form a series. There must be a pattern, not just one prior incident. The pattern is what gives the evidence its probative value: it makes the coincidence explanation implausible.

Third, the person accused must have been concerned in each of those similar occurrences. The similar acts must be linked to this specific accused, not to someone else.

The key to understanding why section 12 escapes the section 82(1) prohibition is that similar facts evidence admitted under section 12 is not admitted to show bad character. It is admitted to prove a specific fact in issue: whether the accused acted intentionally or accidentally, or with or without particular knowledge. These are different purposes, and the distinction of purpose is what legally separates similar facts evidence from impermissible character evidence.

The Probative Value vs Prejudice Test

Even where the technical requirements of section 12 are satisfied, Nigerian courts will not automatically admit similar facts evidence. The court must be satisfied that the probative value of the evidence outweighs its prejudicial effect. If the similar acts are so inflammatory that they are likely to prejudice the court against the accused to an extent disproportionate to the genuine assistance they provide in resolving the facts in issue, the court should exclude them.

This balancing exercise is drawn from the English case of DPP v Boardman,¹ where the House of Lords held that similar facts evidence should be admitted only where its probative force was sufficiently strong to make it just to admit it despite the prejudice it would cause. The Nigerian courts have adopted this approach. The test is not just relevance but whether the similar act evidence actually helps the court resolve the specific issue in dispute in a way that cannot be achieved without it.

The specific feature test is important here. The more specific and distinctive the similarity between the charged act and the previous acts, the stronger the probative value. If a fraudster is accused of using a unique and elaborate scheme to defraud investors, evidence that they used precisely the same scheme against five other investors is highly probative because the coincidence of such a specific technique is very difficult to explain innocently. But if a man is charged with theft and the prosecution merely wants to show he has stolen before, that is not specific enough: it merely shows he is a thief generally, which is exactly the kind of character evidence the law excludes.

The Striking Similarity Requirement

The classic statement of the similar facts test in English law came in R v Makin,² where the Privy Council held that it was not competent to adduce evidence tending to show that an accused had been guilty of criminal acts other than those charged, for the purpose of leading to the conclusion that they were likely to have been guilty of the offence charged. But such evidence was admissible where it tended to rebut a defence of accident or mistake or where it was relevant to a specific issue.

The courts developed the concept of striking similarity: the similar acts must share features so specific, unusual, or distinctive with the charged act that coincidence becomes implausible. In the hotel rape example at the opening of this article, if the prosecution can show that the accused used precisely the same method in each case, lured each victim to the same type of location through the same pretext, and acted in the same distinctive way during each assault, the striking similarity is real. If the prosecution simply wants to show he has assaulted other women, the evidence is insufficient.

Similar Facts Evidence in Civil Cases

The rules on similar facts evidence apply differently in civil cases. In civil proceedings, the character of a party is generally irrelevant, and evidence of past acts is generally inadmissible for the same reasons as in criminal cases.

However, in civil cases where fraud, dishonesty, or similar conduct is alleged, courts have been more willing to admit evidence of a pattern of similar conduct. If a plaintiff in a fraud action can show that the defendant perpetrated similar fraudulent schemes against multiple other people, that evidence is relevant to the issue of whether the defendant’s conduct in this case was fraudulent or merely mistaken.

The applicable framework remains the same: is the similar conduct evidence relevant to a specific issue in the case (such as intention or knowledge), does it have sufficient probative value to outweigh its prejudicial effect, and is the similarity sufficiently specific to carry genuine evidential weight?

Similar Facts and Character Evidence Distinguished

The distinction between admissible similar facts evidence and inadmissible character evidence depends entirely on the purpose for which the evidence is being tendered.

Character evidence is evidence of the accused’s general disposition, reputation, or propensity to behave in certain ways. It is tendered to invite the inference: this person is the type of person who does X, therefore they probably did X in this case. That inference is the forbidden one.

Similar facts evidence is evidence of specific past acts that are relevant to a specific issue in the current case, such as whether the act was accidental or intentional, or whether the accused possessed particular knowledge. It is tendered not to show character but to prove a specific fact.

The same past acts can be character evidence or similar facts evidence depending on the purpose for which they are tendered. A prior conviction for fraud is character evidence if tendered simply to show the accused is dishonest. The same prior conviction is similar facts evidence if tendered specifically to rebut the accused’s defence of mistake in a fraud trial where the similarity of the schemes is striking.

We examine the general rules on character evidence in the article on character evidence in Nigerian law.

A Quick Reference Table

Key Cases

DPP v Boardman (1975) AC 421 The House of Lords held that similar facts evidence is admissible where its probative force is sufficiently strong to make it just to admit it notwithstanding the prejudice it causes. The test is a balancing exercise between probative value and prejudicial effect.

R v Makin (1894) AC 57 The Privy Council established the foundational rule that evidence of other criminal acts is inadmissible merely to show propensity, but is admissible where relevant to rebut a defence of accident or mistake or to prove a specific issue.

R v Griliopoulous (1959) WRNLR 93 The court held that evidence of other instances of receiving stolen goods could not be used to prove the offence presently charged. It must be proved independently. This illustrates the exclusionary rule operating in a Nigerian context.

Problem Question Framework

When a problem scenario involves a prosecution wanting to adduce evidence of past acts by the accused, apply this framework.

First, identify the purpose of the proposed evidence. Is it being tendered to show the accused is generally bad or prone to certain conduct? If yes, it is impermissible character evidence under section 82(1).

Second, ask whether there is a specific issue in the current case, such as intention, knowledge, accident, or mistake, that the similar acts would help resolve. If yes, proceed to the section 12 analysis.

Third, assess whether there is a series of similar occurrences and whether the accused was concerned in each. A single prior incident is generally insufficient. A pattern is required.

Fourth, apply the probative value versus prejudice test. Is the similarity between the past acts and the charged act sufficiently striking to carry genuine probative weight? Does admitting the evidence risk prejudicing the court against the accused in a way that distorts its fact-finding?

Fifth, if the evidence passes all of these tests, conclude that it is admissible as similar facts evidence under section 12. If it fails any of them, it remains excluded as character evidence under section 82(1).

Common Student Mistakes

The first mistake is treating similar facts evidence and character evidence as mutually exclusive categories. They are not. The same evidence can be one or the other depending on its purpose. Always ask: what is this evidence being tendered to prove?

The second mistake is thinking that any past misconduct is admissible if the accused put their character in issue. That rule applies specifically when the accused has given evidence of good character, which triggers the provisions in sections 82(2) and 180(g). It is a separate question from the admissibility of similar facts evidence under section 12.

The third mistake is ignoring the balancing test. Section 12 does not give automatic admissibility. Even where similar acts are relevant, the court must weigh probative value against prejudicial effect. A student who reaches “admissible under s12” without addressing this balance has produced an incomplete answer.

The fourth mistake is failing to identify the specific issue the similar facts are meant to resolve. The evidence must be relevant to something specific: intention, knowledge, absence of accident. A general desire to show the accused has done this before is not enough.

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Footnotes

¹ DPP v Boardman (1975) AC 421.

² R v Makin (1894) AC 57.