The assizes had jurisdiction outside Dublin over the most serious criminal offences, such as treason and murder.
[1] Persons accused of these crimes would first come before the petty sessions, where a justice of the peace or resident magistrate would decide if there was sufficient evidence to justify a trial.
If such evidence existed, the magistrate would issue a bill of indictment and refer the matter to a grand jury, which would decide if the bill was correct and supported by evidence, issuing an indictment.
[4] In the Irish Free State the assizes were abolished under the Courts of Justice Act, 1924.
However, murder, rape and treason (the latter is now extremely rarely prosecuted) must still be heard by a High Court judge and a jury.