Leo v The Queen

Leo appealed against a sentence imposed by the Supreme Court of the Northern Territory. The appeal concerned the application of mandatory minimum sentencing provisions introduced by the *Sentencing Amendment Act 2013* (NT) to offences committed before the commencement of that Act.

The central legal issue before the Court of Appeal was whether the *Sentencing Amendment Act 2013* (NT), specifically sections 78D, 78DA, and 78EA, which introduced mandatory minimum terms of imprisonment for certain violent offences, applied retrospectively to offences committed prior to its commencement. The court was required to determine if the inclusion of the words "whenever committed" in the relevant provisions indicated a legislative intention to impose these mandatory minimums on past conduct.

The Court of Appeal applied the well-established presumption against the retrospective application of penal statutes. It held that for a new legislative provision to impose criminal liability or increase a penalty retrospectively, the intention of Parliament must be expressed clearly and unambiguously. The court found that the phrase "whenever committed" was not sufficiently explicit to overcome the presumption against retrospectivity. Therefore, the new mandatory sentencing provisions were held to apply only to offences committed on or after the commencement of the *Sentencing Amendment Act 2013* (NT).

The appeal was allowed, and the matter was remitted to the Supreme Court for resentencing in accordance with the Court of Appeal's interpretation of the legislation.