Tendency Evidence (NSW)

By James Stevens, Director and Solicitor, Go To Court Lawyers. Last reviewed 15 April 2026.

In criminal trials, a party sometimes seeks to adduce tendency evidence. This is also known as similar fact evidence or propensity evidence. Tendency evidence is relevant in cases where evidence of a pattern of behaviour can be used to prove that a person has or had a tendency that makes it likely that they committed an act. This page examines when tendency evidence is admissible in criminal proceedings in New South Wales.

Legislation

In New South Wales, the laws around tendency evidence are set out in sections 94 to 101 of the Evidence Act 1995.  

The tendency rule

Under section 97 of the Evidence Act 1995, evidence of a person’s character, reputation or conduct is not admissible to establish that the person has or had a tendency unless:

• The party seeking to adduce the evidence gave reasonable notice of their intention to do so to the other party;
• The court thinks the evidence will have significant probative value

In other words, whether the evidence will be admitted depends on the extent to which it could rationally affect the court’s assessment of the probability of a fact at issue.

The coincidence rule

Under section 98 of the Evidence Act 1995, evidence that two or more events occurred is not admissible to prove that a person did an act or had a state of mind on the basis that similarities in the events or circumstances make it improbable that they occurred coincidentally unless:

• The party seeking to adduce the evidence gave reasonable notice of their intention to do so to the other party;
• The court thinks the evidence will have significant probative value

Child sex offences

Under section 97A of the Evidence Act 1995, in a matter where a defendant’s commission of a child sex offence is at issue, evidence is presumed to have significant probative value if it pertains to:

• The defendant’s sexual interest in children
• The defendant acting on a sexual interest in children

However, the court may find that the evidence does not have significant probative value if there are sufficient grounds to do so.

Who may adduce tendency evidence?

Tendency or coincidence evidence is most commonly adduced by the prosecution in an attempt to prove that the accused person has a tendency to behave in a certain way. However, the defence may also rely on tendency evidence provided it complies with the notice requirement.

Pfennig v The Queen  and propensity evidence

The 1994 High Court decision of Pfennig v The Queen established the circumstances under which similar fact evidence is admissible in criminal proceedings.

The case involved the conviction of Pfennig for abducting and murdering a ten-year-old boy. The defendant appealed on the basis that evidence of sex offences he had previously committed against other boys should not have been admitted.

The High Court upheld the defendant’s conviction but provided guidance on the admissibility of similar fact evidence in criminal trials.

The court found that the law does not prohibit the use of propensity reasoning in all circumstances. However, such evidence cannot be admitted simply because it has probative or even strong probative value. The court must be satisfied that the probative value of the evidence is so strong that its admission as evidence should be prioritised over the risk of an unfair trial.

If the risk of an unfair trial is very high, the probative value of the propensity evidence will need to be so high that it makes the accused’s guilt a virtual certainty. Where the risk of an unfair trial is lower, the evidence may be admitted because it is merely probative of the accused’s guilt. Where the prosecution case depends entirely on propensity evidence, the evidence must be so cogent that there is no rational explanation of the evidence that is consistent with the accused’s innocence.

Summary

Tendency evidence may be admitted in a criminal trial where notice has been given to the other party and where the court is satisfied that the evidence has significant probative value. The test for whether tendency evidence should be admitted in a criminal trial was first outlined in the 1994 High Court decision of Pfennig and has since been codified in legislation.

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