Double jeopardy 

Double jeopardy expresses a simple idea — that a person should not be tried twice for the same offence — through several distinct mechanisms. They do different work, and a problem question usually turns on identifying which one the facts engage.

The formal pleas

Autrefois acquit is available where the accused has previously been acquitted of the same offence, or of an offence of which they could have been convicted on that indictment. Autrefois convict is its counterpart following conviction.

Both require the prior proceeding to have been before a court of competent jurisdiction and to have concluded in a verdict. Neither is available where the earlier proceeding was discontinued before verdict, where the jury was discharged without reaching one, or where the conviction has been quashed on appeal with a retrial ordered.

The pleas are also narrow in what counts as the same offence. The test looks to whether the second charge is the same in law and in fact, or one of which the accused could have been convicted on the first indictment. Different offences arising from the same incident are not necessarily caught.

Abuse of process

Because the pleas are narrow, the wider protection is the court's power to stay proceedings as an abuse of process. This reaches situations the pleas do not: a second prosecution on a different charge arising from the same facts, a prosecution that seeks to controvert an earlier acquittal, or repeated prosecutions that are oppressive.

The power is discretionary and exercised sparingly. The question is whether continuing the proceeding would be unjustifiably oppressive to the accused or would bring the administration of justice into disrepute.

Issue estoppel does not apply

In civil proceedings, issue estoppel prevents relitigation of an issue determined between the parties. In Australian criminal proceedings it does not apply. The reason is practical: a jury's general verdict does not disclose which issues were decided, so there is nothing on which an estoppel can fasten.

The protection in criminal cases therefore comes from the pleas and from abuse of process, not from estoppel. Outside the statutory retrial provisions described below, the Crown may not, however, lead evidence to assert that an earlier acquittal was wrong — that is the kind of controverting the abuse of process doctrine addresses.

Double punishment

A distinct application, addressed in Pearce v The Queen (1998) 194 CLR 610, arises at sentence.¹ A single act may constitute several offences with overlapping elements, and while the accused may be convicted of each, they must not be punished twice for what is substantially the same criminality. This is a sentencing principle, not a bar to conviction.

The statutory exceptions

Every Australian jurisdiction has legislated to permit a retrial after acquittal in defined circumstances, reversing the common law position. The categories generally require the offence to be a serious one, and permit retrial where:

• fresh and compelling evidence has emerged that was not adduced at the first trial and is highly probative; or
• the acquittal was tainted — obtained by perjury, bribery or interference with the administration of justice.

Applications are made to an appellate court and require the Director's consent, and the court must be satisfied that a retrial is in the interests of justice.

Discharged juries and mistrials

A trial that ends without a verdict does not engage the pleas. Where a jury is discharged without agreeing, or the trial is aborted for prejudicial material or the illness of a participant, the accused has not been acquitted or convicted and may be retried.

There is no fixed limit on the number of retrials, but repeated failed trials may found an application to stay proceedings as an abuse of process. The court weighs the seriousness of the offence, the strength of the case, the reasons the earlier trials failed, and the burden on the accused of facing the allegation again.

A nolle prosequi or discontinuance likewise leaves the accused without the protection of the pleas, though it may be relevant to abuse of process if used tactically.

Appeals

The prosecution's right to appeal is narrower than the accused's, and the asymmetry is itself an expression of the principle. In most jurisdictions the Crown may:

• appeal against a sentence as manifestly inadequate;
• appeal on a question of law following an acquittal, sometimes only for a declaratory ruling that does not disturb the acquittal; and
• appeal against certain pre-trial rulings before the trial has begun.

The Crown generally cannot appeal against a jury's verdict of acquittal on the facts. Where a conviction is quashed on the accused's appeal, an order for retrial is not double jeopardy, because the conviction has been set aside and the matter returns to where it was.

Double jeopardy formerly operated as a distinct consideration restraining the increase of a sentence on a Crown appeal. Several jurisdictions have legislated to remove it, directing the court to disregard the element of double jeopardy involved in the appeal when re-sentencing.

The relationship with other proceedings

The pleas apply to criminal proceedings. They do not prevent:

• civil proceedings arising from the same conduct, including a claim by the victim, since the parties and the standard of proof differ;
• disciplinary or regulatory proceedings by a professional body or regulator; or
• confiscation or forfeiture proceedings, which are generally characterised as civil.

Nor do they prevent prosecution in a different jurisdiction for the same conduct, though most jurisdictions have provisions preventing double punishment where conduct is an offence under both Commonwealth and state law.

Applying this in a problem question

1. Identify precisely what the earlier proceeding decided, and whether it concluded in a verdict.
2. Test the formal pleas first — same offence in law and fact, or one available on the earlier indictment.
3. If the pleas fail, turn to abuse of process, which is where most modern arguments live.
4. Do not reach for issue estoppel; say expressly that it does not apply in criminal proceedings.
5. Consider the statutory retrial exceptions if the facts involve fresh evidence or a tainted acquittal.

Pearce is a strong preference, not a prohibition. In Johnson v The Queen [2004] HCA 15² Gummow, Callinan and Heydon JJ described fixing a sentence for each offence and aggregating them as "the orthodox, but not necessarily immutable, practice", and said expressly at [26] that "Pearce does not decree that a sentencing judge may never lower each sentence and then aggregate them for determining the time to be served".

Self-check

• Have I confirmed the earlier proceeding reached a verdict?
• Have I applied the narrow "same offence" test rather than a same-facts test?
• Have I avoided importing civil issue estoppel into a criminal answer?
• Have I kept double punishment as a sentencing principle rather than a bar to conviction?