The Act was found invalid, however, on the ground that since the Supreme Court of New South Wales had been invested with federal jurisdiction, it must not be required to perform a function "incompatible" with the exercise of the judicial power of the Commonwealth. To that extent, the States are not free to legislate as they please with respect to their own courts. A requirement to order the "preventive detention" of someone who has not been charged with any criminal offence was found "incompatible" with the exercise of Federal judicial power. In this rather circuitous manner, the High Court has found a limited constitutional guarantee of due process.