Tendency and coincidence evidence is some of the most contested material in a criminal trial. Used well by the prosecution, it can shape a jury’s view of an accused before the central facts are even reached. Used improperly, it invites exactly the reasoning the law of evidence is built to guard against. This article sets out what tendency and coincidence evidence are, the gateway to admitting them in NSW, how the 2020 amendments changed the landscape, and the grounds on which a defence can respond.

This is a practitioner-focused overview of NSW law as at 2026. It is general information, not legal advice, and it is not a substitute for close analysis of the evidence in a given matter.

Key points

  • Tendency evidence (section 97) goes to a person’s propensity; coincidence evidence (section 98) goes to the improbability of similar events occurring by chance. Both are presumptively inadmissible.
  • Admissibility requires reasonable notice and significant probative value. Prosecution evidence about a defendant must also clear the further restriction in section 101.
  • Since the 2020 amendments, the section 101(2) test is that probative value outweighs the danger of unfair prejudice, a lower bar than the former “substantially outweighs any prejudicial effect”.
  • Leading authorities: Hughes v The Queen (no fixed similarity requirement) and IMM v The Queen (probative value assessed on the evidence taken at its highest).
  • The 2020 amendments set aside common law propensity rules (section 94(4)), removed collusion, concoction and contamination from the probative value assessment (section 94(5)), and created a presumption in child sexual offence proceedings (section 97A).

What is tendency evidence?

Tendency evidence goes to a person. Under section 97 of the Evidence Act 1995 (NSW), it is evidence of a person’s character, reputation, conduct, or a tendency they have or had, used to prove that the person has or had a tendency to act in a particular way or to have a particular state of mind.

The reasoning is propensity based: because the accused behaved a certain way before, they were more likely to have behaved that way on the occasion charged. That is precisely why the law treats it with caution.

What is coincidence evidence?

Coincidence evidence goes to events. Under section 98, it is evidence that two or more events occurred, used to prove that a person did a particular act or had a particular state of mind on the basis that, given similarities in the events or their circumstances, it is improbable that they occurred coincidentally.

Coincidence evidence can include the accounts of two or more witnesses each claiming to be a victim of the accused, tendered to prove, from the similarities, that the accused did an act in issue.

The general position, and why

Tendency and coincidence evidence are presumptively inadmissible. The reason is prejudice. This kind of evidence carries a real risk that a jury will give it more weight than it deserves, reason from bad character to guilt, or be diverted from the actual issues in the trial. The framework in Part 3.6 of the Act exists to admit this evidence only where its genuine probative force justifies that risk.

The gateway to admissibility

For the prosecution to lead tendency or coincidence evidence against an accused, several requirements stack together.

Relevance. As with any evidence, it must be relevant to a fact in issue under sections 55 and 56.

Reasonable notice. The party seeking to adduce the evidence must give the other party reasonable notice in writing, in accordance with the regulations (sections 97(1)(a) and 98(1)(a)). The court may dispense with the notice requirement under section 100.

Significant probative value. The court must think the evidence will have significant probative value, either by itself or together with other evidence (sections 97(1)(b) and 98(1)(b)). This is the central threshold. In assessing it, the court takes the evidence at its highest, and questions of credibility and reliability are generally left to the tribunal of fact: IMM v The Queen (2016) 257 CLR 300. In Hughes v The Queen (2017) 263 CLR 338, the High Court held there is no fixed requirement of a particular feature of similarity between the tendency and the charged conduct. The assessment turns on the facts: the extent to which the evidence supports the asserted tendency, and the extent to which that tendency makes the facts in issue more likely.

The section 101 restriction. For tendency or coincidence evidence about a defendant that is adduced by the prosecution, there is a further restriction. Since the 2020 amendments, section 101(2) provides that the evidence cannot be used against the defendant unless its probative value outweighs the danger of unfair prejudice to the defendant. This is the current wording, and it matters, because it replaced the older and more demanding formulation discussed below.

What the 2020 amendments changed

The Evidence Amendment (Tendency and Coincidence) Act 2020 commenced on 1 July 2020 and reshaped this area. Four changes are worth holding in mind.

A lower section 101 threshold. The former section 101(2) required that probative value “substantially outweighs any prejudicial effect” on the defendant. The amendment removed that wording and substituted “outweighs the danger of unfair prejudice to the defendant.” Any analysis or precedent framed around the old “substantially outweighs” test needs to be read with the current wording in front of you.

Common law propensity rules set aside. Section 94(4) now makes clear that common law or equitable rules restricting propensity or similar fact evidence are not relevant when applying this Part to a defendant.

Collusion, concoction and contamination removed from the probative value assessment. Section 94(5) provides that, when assessing probative value for the purposes of sections 97(1)(b), 97A(4), 98(1)(b) and 101(2), the court cannot have regard to the possibility that the evidence is the result of collusion, concoction or contamination. Those possibilities become questions of credibility for the tribunal of fact, not gatekeeping questions of admissibility. This displaced the earlier common law approach in this respect.

A presumption in child sexual offence proceedings. Section 97A introduces a presumption that tendency evidence about a defendant’s sexual interest in children, or about the defendant acting on that interest, has significant probative value for the purposes of sections 97(1)(b) and 101(2). The presumption can be displaced only where the court is satisfied there are sufficient grounds to find the evidence lacks significant probative value (section 97A(4)), and certain matters cannot be taken into account in reaching that view.

How the defence responds

Because the prosecution must satisfy each element, each is a point of resistance. A defence response is built by testing the evidence against the framework rather than treating admissibility as a foregone conclusion.

Notice. Confirm that proper written notice was given in accordance with the regulations. Deficient or late notice is a live issue, subject to the court’s power to dispense under section 100.

Significant probative value. This is usually the main battleground. The argument is that the evidence, taken at its highest, does not strongly support the asserted tendency, or that the tendency does not meaningfully advance proof of a fact in issue. The Hughes framework guides that analysis, and the strength of any similarities, the specificity of the tendency, and the number and quality of the supporting instances all feed into it.

The section 101 balance. Even where significant probative value is established, prosecution evidence against a defendant must clear section 101(2). The defence identifies the specific unfair prejudice the evidence carries and argues that probative value does not outweigh it.

What is no longer available. It is important to advise realistically. The possibility that complainants have colluded, or that accounts have been concocted or contaminated, can no longer be used to defeat probative value at the admissibility stage. That line of attack now belongs to cross-examination and submissions on the facts, where it goes to the weight a jury gives the evidence.

Practice insight: Peter Godkin

On a tendency or coincidence notice, the instinct is to reach for concoction or collusion. Since the 2020 amendments that argument no longer keeps the evidence out. It goes to the jury on weight. So the real work is earlier and narrower. I look first at whether the notice actually articulates the tendency with enough precision to be tested, and then at whether the asserted tendency does any genuine work in proving a fact in issue, taken at its highest. If it does not, that is the argument to run at admissibility, and the concoction point is one to hold for cross-examination.

Why experienced trial counsel matters

Tendency and coincidence applications are frequently decisive, and they are argued on the detail of the particular evidence rather than on general principle. The 2020 amendments have made careful, current analysis more important, not less, because the thresholds and the permissible considerations have shifted. Getting the objection right, and preserving the point for any appeal, calls for counsel who runs these arguments.

Peter Godkin is a criminal barrister at 8 Windeyer Chambers, called to the NSW Bar in 2014, with District Court and Supreme Court trial experience. He accepts briefs from solicitors, as well as direct access briefs, in criminal trials, including advice on and argument of contested tendency and coincidence objections. To brief Peter, or to discuss a tendency or coincidence notice in a current matter, contact chambers on 02 9235 3033.

Frequently asked questions

What is the difference between tendency and coincidence evidence? Tendency evidence relates to a person and shows a tendency to act in a particular way or to have a particular state of mind. Coincidence evidence relates to two or more events and uses their similarities to show it is improbable they occurred coincidentally. Tendency is about propensity; coincidence is about improbability.

Is tendency or coincidence evidence admissible in NSW? It is presumptively inadmissible, but it can be admitted where the requirements in Part 3.6 of the Evidence Act 1995 are met, including reasonable notice and significant probative value, and, for prosecution evidence against a defendant, the further restriction in section 101.

What is the test for significant probative value? The court must think the evidence will have significant probative value. In assessing it, the court takes the evidence at its highest, with credibility and reliability generally left to the tribunal of fact (IMM v The Queen (2016) 257 CLR 300). Following Hughes v The Queen (2017) 263 CLR 338, there is no rigid requirement of a common feature of similarity; the court assesses how strongly the evidence supports the asserted tendency and how strongly that tendency supports proof of a fact in issue.

What did the 2020 amendments change? The Evidence Amendment (Tendency and Coincidence) Act 2020 lowered the section 101(2) test to “probative value outweighs the danger of unfair prejudice”, set aside common law propensity rules for defendants (section 94(4)), removed collusion, concoction and contamination from the probative value assessment (section 94(5)), and introduced a presumption of significant probative value in child sexual offence proceedings (section 97A).

Can the possibility of collusion or concoction keep the evidence out? Not at the admissibility stage. Under section 94(5), the court cannot consider that possibility when assessing probative value. It remains relevant to the weight the tribunal of fact gives the evidence, so it is addressed through cross-examination and submissions rather than on the admissibility application.

How can the defence challenge this evidence? By testing each requirement: whether proper notice was given, whether the evidence truly has significant probative value, and, for prosecution evidence against a defendant, whether probative value outweighs the danger of unfair prejudice under section 101.

When should a solicitor brief counsel on a tendency or coincidence notice? As early as possible, ideally when the notice is served or anticipated. The response turns on close analysis of the specific evidence, the objection is often decisive, and early involvement allows the notice to be tested properly and the record to be built for any appeal.

This article is a general overview of NSW law as at 2026 and is not legal advice. The law of tendency and coincidence evidence is detailed and fact-sensitive, and it continues to be developed by the courts. Analysis of any particular matter requires close attention to the specific evidence.

 

Further reading (authoritative sources):