R v Kidman

The case of *R v Kidman* involved a criminal trial before the High Court of Australia, where the accused, Arthur Kidman and others, were charged with conspiracy to defraud the Commonwealth. The dispute centred on the validity of the *Crimes Act 1915* (Cth), which retrospectively created the offence of conspiring to defraud the Commonwealth and purported to apply from a date prior to its enactment. The accused sought to quash the indictment on several grounds, including the competence of the Commonwealth Parliament to enact such retrospective legislation and the High Court's jurisdiction to hear such matters.

The High Court was required to determine several key legal issues. Firstly, whether the Commonwealth Parliament possessed the power to enact retrospective criminal laws, specifically an *ex post facto* law, under the Constitution. Secondly, it had to consider whether the Parliament could confer original jurisdiction upon the High Court to hear offences against the common law of the Commonwealth. Finally, the Court needed to ascertain if the *Crimes Act 1915* validly conferred jurisdiction on the High Court for the charged offence and whether the indictment constituted a matter to which the Commonwealth was a party for the purposes of the Constitution.

The Court, by majority, held that the *Crimes Act 1915* was a valid exercise of parliamentary power. Griffith C.J. reasoned that while the Parliament could not enact a purely *ex post facto* law, it had the power under section 51(xxxix) of the Constitution to codify the common law of the Commonwealth applicable to the execution of its powers. Such a statute, particularly concerning procedural aspects, could be construed as retrospective. Isaacs, Higgins, Gavan Duffy, Powers, and Rich JJ. held that the Parliament's legislative power was plenary within constitutional limits, including the power to make *ex post facto* laws. They further reasoned that section 51(xxxix) granted broad power to legislate on incidental matters, which encompassed the *Crimes Act 1915*. Isaacs J. also noted that the common law of Australia recognised the "peace of the King" in relation to the Commonwealth, making obstructions to its functions a justiciable matter.

The motions to quash the indictment were refused. The Court found that there was a common law of the Commonwealth, and that conspiring to defraud the Commonwealth constituted an offence against this common law. The *Crimes Act 1915* was deemed a valid law, either as a codification of this common law or as a plenary exercise of legislative power, and the High Court possessed the necessary original jurisdiction to hear the matter.