Post-acquittal retrials for serious offences in the Irish criminal justice process: lessons from England and Wales

The ancient common law prohibition on multiple trials, known as the double jeopardy principle or its Latin equivalent nemo debet bis vexari, is a procedural defence that prohibits the prosecution of an accused for a criminal offence for which he has already been acquitted or convicted following a trial on the merits by a court of competent criminal jurisdiction.  A peremptory plea of autrefois acquit or autrefois convict may be entered meaning the defendant was formerly acquitted or convicted of the same (or substantially the same) offence.  When the pleas in bar are raised, evidence will be placed before the court, which will normally rule as a preliminary matter whether the plea is substantiated, and if it so finds, the projected trial will be estopped. Double jeopardy can only arise when there has been a previous criminal trial.  In many countries, the protection against double jeopardy is a constitutional right while in others it is afforded by statute law.    Statutory modification of the principle in England and Wales has been the model for reform in several common law jurisdictions, which allow post-acquittal retrials in limited circumstances where new and compelling evidence emerges or where there acquittal is tainted.  This article critically evaluates double jeopardy law reform in Ireland in the light of reforms in England and Wales and possible implications for the trial of offences in the Irish criminal justice process.