A tendency evidence voir dire is a hearing held inside a criminal trial, before a jury is empanelled or in the jury's absence, to determine whether proposed tendency evidence meets the legal threshold for admission. It's a procedural mechanism that fuses the evidentiary rules around tendency evidence with the general voir dire process, creating a distinct battleground where cases are frequently won or lost well before closing addresses are delivered.
Why tendency evidence needs its own voir dire
Tendency evidence is among the most prejudicial evidence a prosecutor can seek to introduce. It asks a jury to reason from a defendant's past conduct to a conclusion about what they did on the occasion charged. Because that reasoning path is so familiar to a lay fact-finder, and so prone to misuse, the Evidence Act 1995 (NSW) imposes strict conditions before such evidence can be placed before a jury at all.
The threshold question is whether the probative value of the proposed tendency evidence substantially outweighs any unfair prejudice to the defendant. That balancing exercise is a legal question, not a factual one, and it belongs to the judge alone. A voir dire is the procedural vehicle for resolving it. The jury leaves the courtroom, witnesses may be called, and the parties argue the admissibility question on the evidence as it would actually appear at trial.
Courts don't simply accept a prosecutor's characterisation of what the evidence shows. The defence can, and should, test every assumption that underpins the application.
What happens at the hearing
The prosecution carries the burden of demonstrating that the tendency evidence satisfies the requirements in section 97 of the Evidence Act. In practice that means establishing three things: that reasonable notice was given, that the evidence has significant probative value, and that the probative value substantially outweighs the danger of unfair prejudice.
The voir dire itself can take several forms. Sometimes the judge rules on the papers, considering affidavit material and submissions without calling any witness. More often, where the tendency evidence involves a complainant or a third party, that person is called to give evidence in the absence of the jury so the judge can assess the quality and specificity of what they would say. The defence can cross-examine.
This is not a dress rehearsal. It's a genuine forensic exercise with binding consequences. If the judge excludes the evidence, it stays out. The jury never hears it, and the prosecutor cannot later attempt to sneak it in through the back door of another question.
How it connects to the tendency evidence notice requirements
A voir dire cannot proceed unless the notice requirements have first been satisfied. The prosecution must serve a formal notice identifying the tendency being asserted and the facts relied upon to establish it. If the notice is defective or late, the defence may object to the evidence being considered at all, before any substantive admissibility argument is heard.
Understanding what a tendency evidence notice must contain is therefore a prerequisite to running an effective voir dire. A notice that describes the tendency in vague terms, or that fails to identify the specific acts relied upon with sufficient precision, can itself become the basis for exclusion. Defence lawyers who spot this early can shut down the application before the balancing exercise even begins.
The bundles hearing and the voir dire: how they interact
In complex multi-complainant trials, courts sometimes conduct a tendency evidence bundles hearing before, or alongside, the voir dire. That hearing addresses disputes about which specific acts or incidents will be placed before the court in support of the tendency application. The two processes are distinct but related. A bundles hearing refines the factual substratum; the voir dire tests whether what remains actually crosses the admissibility threshold.
Conflating the two is a common mistake. The bundles hearing does not determine admissibility. It determines what the admissibility argument will be about. Defence practitioners who understand the difference can structure their challenge across both hearings more precisely, rather than running a single blunt objection that fails to land on either front.
Grounds the defence typically runs
The arguments at a tendency evidence voir dire cluster around a few core themes. First, the defence will challenge whether the proposed tendency is genuinely specific enough to have real probative value. A tendency to act in a particular way toward a particular class of person in a particular type of situation carries far more weight than a vague assertion of general bad character. Vague tendencies are easier to exclude.
Second, the defence will identify every source of unfair prejudice: the risk of reasoning prejudice, where the jury reasons from bad person to guilty verdict; the moral prejudice of disliking the accused because of past conduct; and the practical prejudice of using hearing time to investigate collateral matters. Courts take these seriously. The tendency evidence objection process gives defence lawyers a structured way to articulate each of these risks in writing before the hearing begins.
Third, where the tendency evidence comes from a co-complainant in a multi-count trial, the defence may argue that the complainants' accounts are too similar because they were contaminated by contact with each other. Cross-pollination of accounts is not probative tendency evidence. It's a reliability problem dressed up as corroboration.
What happens if the judge admits the evidence
Losing the voir dire is not the end of the contest. If the judge rules the evidence admissible, the jury is brought back and hears it. But the defence is then entitled to ask the judge to give a direction limiting the jury's use of the evidence to the specific tendency identified. The direction must be precise. A generic warning that the jury should not use past conduct as proof of guilt on the current charge is insufficient if it doesn't also explain exactly what reasoning is permissible.
An error in how the judge frames that direction can itself become a ground of appeal, even where the original admissibility ruling was correct. Defence lawyers therefore need to think about the direction from the moment the voir dire begins, not just after the ruling comes down.
Why specialist representation matters at a voir dire
A tendency evidence voir dire is technical, contested, and consequential. It requires close familiarity with the Evidence Act, with the case law on probative value and unfair prejudice, and with the practical mechanics of calling and cross-examining witnesses in the absence of a jury. It also requires the lawyer to hold two timelines in mind at once: the immediate question of admissibility, and the downstream question of how any admitted evidence will be managed through the trial and beyond.
Ann Valos Criminal Law handles complex criminal matters including serious charges where tendency evidence is regularly in dispute. Ann Valos is an accredited criminal law specialist with over 15 years of experience in these proceedings, and the firm's team brings over 30 years of combined experience to contested hearings of this kind.
Key takeaways
- A tendency evidence voir dire is a separate hearing in the jury's absence that tests whether past conduct evidence can be admitted at trial.
- The prosecution must prove that the probative value of the evidence substantially outweighs any unfair prejudice to the defendant.
- The defence can call witnesses, cross-examine, and run multiple grounds of objection including notice defects, vagueness, and contamination.
- A successful voir dire exclusion keeps the evidence out entirely. An unsuccessful one still shapes how the trial is managed and what directions the jury receives.