Should my client testify in their own case? A guide for legal professionals in New Zealand

The decision to have your client testify at trial is one of the most pivotal strategic choices in criminal defence. While New Zealand law robustly protects the right to silence, practical considerations and variables often make this theoretical protection more complex in application.
This guide equips legal professionals with a structured framework for understanding, navigating and guiding clients through this critical decision point.
Below is a structured briefing you can walk the client through. It explains:
(i) the governing law in Aotearoa New Zealand,
(ii) the principal advantages and disadvantages of giving evidence, (
iii) the key variables that tend to drive the decision, and
(iv) a step-by-step framework you can use to reach – and clearly document – an informed choice with the client.

Executive snapshot

In New Zealand a defendant has an absolute right to silence and no adverse inference of guilt may be drawn merely because they do not testify – a position codified in the Evidence Act 2006 and reinforced by the New Zealand Bill of Rights Act 1990.  
Testifying can be powerful: jurors often want to “hear it from the horse’s mouth”, and first-person evidence is sometimes critical where intent, self-defence, or good-faith reliance on legal advice are central. On the other hand, it also opens the accused to cross-examination, and if the accused’s narrative is found to be inconsistent with their prior statement(s) (if any), it may also expose them to consequences such as impeachment with prior convictions, memory challenges, and evaluations of demeanour that psychological research shows are often unreliable.
The “best” course of action therefore depends on a matrix of legal, evidential, and personal variables outlined in this article.

1. Legal framework (New Zealand)

The two main types of legal systems used around the world are Common Law and Civil Law. New Zealand follows the Common Law system, along with many other countries, including:
  • United Kingdom (England, Wales, Northern Ireland)
  • Australia
  • Canada (except Quebec)
  • India
  • Ireland
  • Singapore
  • Malaysia
  • Hong Kong SAR
  • United States (except Louisiana)
  • New Zealand
These jurisdictions share similar legal principles and court decisions in both civil (torts, breach of contract, family law) and criminal (police prosecutions) jurisdictions draw heavily from existing case law or
precedent”.
In contrast to Common Law jurisdictions, Civil Law systems are used in many countries worldwide, including:
  • France
  • Netherlands
  • China
  • South Korea
  • Mexico
  • Quebec (Canada)
  • Louisiana (United States)
  • Brazil
  • Japan
  • Germany
  • Italy
  • Spain
Civil Law systems are characterised by, among other things, codification of their constitution as the primary source of law, with less emphasis on judicial precedent compared to Common Law systems.
While the idea of key features of the Rule of Law, Separation of Powers and the hierarchical system which determines whether precedent is ‘binding’ or ‘influential’ aim to keep judicial decision-making as consistent as possible, this is theoretically

1.1. Statutory and constitutional rights

On paper, two key pieces of legislation, and jury directions as provided by a judge, are in place to ensure that the jury only takes into consideration what is relevant, and disregards anything that is irrelevant when making their decision.
  • Evidence Act 20061^1– A defendant cannot be compelled to give evidence and silence may not be treated as proof of guilt.2^2
  • NZBORA 1990, s 23(4) – Reinforces the privilege against self-incrimination.
  • Jury directions – Standard directions explicitly prohibit negative inferences; appellate authority treats failure to give such a “no adverse inference” instruction as reversible error.

1.2. Exposure once the defendant testifies

  • Cross-examination is unrestricted except by the ordinary rules on relevance, propensity (ss 40–43 Evidence Act), and burdensome questioning (s 85).
  • If the accused testifies, prior convictions may become admissible to impeach credibility under s 37 or as propensity evidence – subject to a probative/prejudice balancing test.

2. Advantages of taking the stand

Benefit
Potential significance
Illustrative authority
Direct narrative
The jury hears the defendant’s own words rather than filtered through counsel.
High-profile cases (e.g., Kyle Rittenhouse) show jurors value first-person context in self-defence scenarios.
Humanising/credibility
Can counteract negative stereotypes and make the defendant appear more relatable.
Social-science studies on juror perception cited by Judicature emphasise demeanor effects.
Essential mental-state evidence
Some defences (self-defence, lack of intent, honest reliance on legal advice) require proof of subjective state only the defendant can supply.
Courts scrutinise “involvement of counsel” defences (Bankman-Fried, Trump) where the defendant did not testify.
Opportunity to rebut damaging evidence
Live testimony lets the accused explain inconsistencies, forensic results, or adverse inferences raised by the prosecution.
Temple Law review of cross-examination strategy.

3. Disadvantages and risks

Risk
Mechanism
Key sources
Cross-examination stress & error
Skilled prosecutors exploit inconsistencies; a single mis-statement can devastate credibility.
Temple Law Guide on Pitfalls.
Impeachment with prior convictions
Once on the stand, the shield against “bad-character” evidence weakens.
Evidence Act 2006 ss 37–43; US Rule 609 analogue.
Demeanour misinterpretation
Jurors over-rely on confidence, eye contact, accent; scientific literature shows these cues are poor truth indicators.
Duke Judicature article; Otago dissertation on mental-condition witnesses.
Psychological, cultural, or language hurdles
Anxiety, PTSD, second-language issues may impair clarity.
Otago “Weight of Silence” study.
Perjury exposure
Inaccurate statements, even if unintentional, risk perjury charges.
Missouri Bar ethics commentary.
Shifted jury expectations
Some empirical data suggest jurors still expect an innocent person to speak, but acquittal data are mixed and heavily confounded.
TBA blog reviewing statistical studies.

4. Decision-making variables

4.1 Evidential strength & alternative narrative

  • Prosecution case: Weak or circumstantial evidence often counsels against testifying – the Crown still bears the burden of proof.
  • Necessity of subjective explanation: Where intent or belief is central, silence may create an evidentiary gap.

4.2 Defendant-specific factors

  • Prior convictions and propensity evidence susceptibility.
  • Credibility & presentation skills: demeanour, linguistic fluency, emotional regulation.
  • Mental or physical condition that could affect testimony quality.

4.3 Procedural context

  • Availability of corroborating witnesses or documents – if others can tell the story, the defendant may stay silent.
  • Potential plea negotiations – going to trial and testifying may foreclose favourable sentencing discounts achieved through early pleas.
  • Media attention – high-profile trials magnify cross-examination missteps and create reputational spill-over.

4.4 Legal safeguards

  • Jury instructions on silence – ensures no adverse inference, but assess whether jurors will truly follow it.
  • Judicial control of cross-examination – the judge can exclude unfair or repetitious questioning (s 85 Evidence Act).

5. Practical framework for advising the client

  1. Evidence audit – Map every contested fact, identify which can be proved via other sources, and flag those requiring the client’s own account.
  1. Prior-conviction risk assessment – Apply ss 37–43 Evidence Act balancing test; prepare submissions to exclude or limit propensity evidence if the client chooses to testify.
  1. Mock cross-examination – Conduct practice sessions to test stamina, memory, and demeanour under stress, documenting performance issues.
  1. Psychological preparedness check – Consider formal evaluation if cognitive or mental-health factors could impair testimony.
  1. Cultural & language support – Engage interpreters or communication specialists where English is not the client’s first language.
  1. Document the advice – Record the pros, cons, and client’s informed election to protect against later complaints of ineffective assistance.

6 Communicating the analysis to the client

Use plain, respectful language and visual aids.
You might want to sketch a two-column chart (“Benefits if I speak” / “Risks if I speak”) and then layer the bespoke variables on top.
Ground every point in the governing legal rules (“the law says jurors must not hold silence against you…”) before moving to practical realities (“but the research shows some jurors struggle to follow that instruction…”).
Finish by reiterating that the decision is the client’s alone and that your role is to ensure it is fully informed, voluntary, and contemporaneously recorded.

Conclusion

Whether to testify is rarely a simple “yes” or “no”. By systematically weighing (i) legal protections, (ii) evidential necessities, (iii) personal credibility factors, and (iv) strategic courtroom dynamics, counsel can present the client with a clear, evidence-based roadmap. That transparency fosters trust, mitigates future complaints, and – most importantly – positions the client to make the decision that best serves their defence.

Footnotes

1^1 Evidence Act 2006.
2^2 Above n 1 at ss 25, 28, 95.

Further reading

From Ghilaine Maxwell to Kim Potter…
The decision to testify or not in one’s defense during a criminal trial is a pivotal and risky move for defendants, as illustrated by recent high-profile cases. Ghislaine Maxwell, linked to Jeffrey Epstein's sex trafficking operations, chose not to testify in her trial. Conversely, defendants like Kyle Rittenhouse, Travis McMichael, Elizabeth Holmes, and Jussie Smollett opted to take the stand, each facing varying outcomes. Legal experts explain that testifying can humanize the defendant and allow jurors to hear a firsthand account, which can be crucial in self-defense cases. However, it also exposes them to potentially harmful cross-examinations and past criminal records, which can bias the jury against them. Despite a defendant’s right to remain silent, jurors often infer guilt if they do not testify. The unpredictability of juror decisions makes the choice to testify highly consequential, evidenced by mixed verdicts in recent cases.
The defense of involvement - as opposed to advice - of counsel
 

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