Monis v The Queen & Anor; Droudis v The Queen & Anor

The High Court of Australia considered appeals by Man Haron Monis and Amirah Droudis against their convictions for offences arising from the Lindt Cafe siege. Monis was convicted of murder and attempted murder, while Droudis was convicted of accessory after the fact to murder and accessory after the fact to attempted murder. The appeals concerned the admissibility of certain evidence and the fairness of the trial.

The central legal issues before the High Court were whether the trial judge erred in admitting evidence of Monis's prior criminal conduct and whether the admission of this evidence, along with other alleged errors, rendered the trial unfair. Specifically, the court had to determine if the evidence of Monis's prior offending was improperly admitted as character evidence or if it was relevant for other permissible purposes, such as establishing motive, intent, or a system of conduct. The court also considered whether the cumulative effect of any errors prejudiced the appellants' right to a fair trial.

The High Court, by majority, found that the evidence of Monis's prior criminal conduct was relevant to establishing his motive and intent in relation to the siege offences. The majority reasoned that this evidence demonstrated a pattern of behaviour and a predisposition towards extremist ideologies and violent acts, which was probative of his state of mind during the siege. While acknowledging that some of the evidence was prejudicial, the court concluded that its probative value outweighed its prejudicial effect and that its admission did not occasion a miscarriage of justice. The court therefore dismissed the appeals.