News · Criminal law explainer
What is double jeopardy in NSW and the ACT?
Double jeopardy is one of the oldest protections in the criminal law, and one of the most misunderstood. It stops a person being prosecuted again for the same offence. This note explains what the rule protects, the limited exceptions that now exist for serious offences, and how it works in New South Wales and the ACT.
By Aaron Kernaghan · Published 3 September 2026
Double jeopardy is the long-standing rule that a person cannot be tried again for the same offence after being acquitted or convicted of it. It protects people from repeated prosecution for the same conduct. In NSW there are limited exceptions for certain very serious offences, where a retrial can be ordered after an acquittal if there is fresh and compelling evidence or the acquittal was tainted.
What is the double jeopardy rule?
The double jeopardy rule is that a person who has been acquitted or convicted of an offence cannot be tried again for the same offence. Once a matter has been finally decided, it is over, and the person cannot be put in jeopardy of conviction for it a second time.
It is a protection against the power of the state. Without it, the prosecution could keep trying a person again and again until it obtained a conviction, which would be oppressive.
What does it protect?
The rule protects the finality of criminal proceedings and the individual against repeated prosecution. Once acquitted, a person is entitled to treat the matter as closed and to get on with their life without fear of being tried again for the same thing.
It also supports confidence in verdicts. A verdict, once given, stands, rather than being endlessly reopened. The rule is a foundation of a fair system.
Are there exceptions?
Yes, but they are limited. New South Wales reformed the law to allow, for certain very serious offences such as those carrying life imprisonment, a retrial after an acquittal in defined circumstances. The main grounds are where there is fresh and compelling evidence of guilt, or where the acquittal was tainted, for example by perjury or interference with the trial.
These exceptions are narrow and apply only to the most serious offences, with the leave of the court. For the vast majority of matters, the double jeopardy rule applies fully and there is no retrial after an acquittal.
How does it work in NSW and the ACT?
In New South Wales, the reforms allowing a retrial for serious offences are set out in legislation, and applications are made to the Court of Criminal Appeal. In the ACT, the double jeopardy rule also applies, with its own arrangements. The core rule, no second trial for the same offence, is the same in both.
So the general position across both jurisdictions is that a person cannot be tried twice for the same offence, subject to the narrow exceptions for the most serious matters.
What about related principles?
Double jeopardy is related to, but distinct from, other principles. A person can generally raise a previous acquittal or conviction as a bar to a fresh charge for the same matter. The rule is also connected to the principle that a person should not be punished twice for the same conduct.
These principles work together to protect finality and fairness. If you are facing a charge that you think relates to a matter already decided, get advice, because a previous acquittal or conviction can be a complete answer.
Frequently asked.
What is double jeopardy?
The rule that a person who has been acquitted or convicted of an offence cannot be tried again for the same offence. It protects against repeated prosecution for the same conduct.
Can you be tried twice for the same crime in NSW?
Generally no. The double jeopardy rule prevents it. There are limited exceptions for certain very serious offences, where a retrial can be ordered after an acquittal in defined circumstances.
What are the exceptions to double jeopardy?
For certain very serious offences, a retrial after an acquittal can be ordered where there is fresh and compelling evidence of guilt, or where the acquittal was tainted, for example by perjury or interference with the trial, with the leave of the court.
Does double jeopardy apply in the ACT?
Yes. The double jeopardy rule applies in the ACT as well, with its own arrangements. The core rule, no second trial for the same offence, is the same in both NSW and the ACT.
What if a new charge relates to a matter already decided?
A previous acquittal or conviction can be a bar to a fresh charge for the same matter, and can be a complete answer. If you are facing such a charge, get advice.
To speak to a criminal defence lawyer, call Aaron Kernaghan on 0421 717 019.
This article is written by Aaron Kernaghan, criminal defence lawyer at Good Legal Lawyers, as at 3 September 2026. It is commentary and reflects the personal opinion of the author only. It is not legal advice, it is not a substitute for advice on your own matter, and it does not purport to be accurate or complete. Any matter referred to may be before the court and any person charged is presumed innocent. For advice on a specific matter, contact Aaron Kernaghan on 0421 717 019 or contact the firm.
More criminal-law commentary by Aaron Kernaghan.
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