The High Court has decided a matter relating to the constitutionality of the Northern Territory’s new police arrest and detention powers, holding by majority that the powers are not invalid. Division 4AA of the Police Administration Act (NT), inserted into the Act in December 2014, empowers a police officer to arrest a person without a warrant where the office believes, on reasonable grounds, that the person has committed, was committing, or about to commit an ‘infringement notice offence’: 35 different offences fall under this definition, many of which are minor or public order type offences. A person can be held for four hours (or longer if the officer believes the person is intoxicated) after which time they may be released unconditionally, released with an issue of an infringement notice, released on bail, or brought before a justice of the peace or a court. There is no judicial involvement during the time of detention, and, excepting the final outcome of bringing the person before a court, no judicial oversight of the decision to detain, or practical opportunity to challenge the detention. This scheme has come to be known as the ‘paperless arrest’ scheme. The plaintiffs challenged the powers as first, contravening the separation of judicial and executive powers enshrined in ch III of the Constitution and, secondly, undermining the institutional integrity of the courts contrary to the principle in Kable v DPP (NSW) [1994] HCA 24.

The questions posed in the special case asked whether div 4AA is invalid on the ground that a) it purports to confer on the NT executive a power to detain that is penal or punitive in character, which would be beyond the powers of the Commonwealth Parliament in s 122 of the Constitution as limited by the separation of powers, and therefore beyond the powers of the NT Legislative Assembly, and/or b) it purports to confer on the NT executive (rather than the courts) a power of detention that is penal or punitive in character and thus undermines or interferes with the institutional integrity of the NT courts, contrary to the Constitution.

The Court held that div 4AA did not confer a power to detain that was penal or punitive and that it was otherwise unnecessary to answer question (1)(a), and that the power did not interfere with the institutional integrity of the NT courts. That result was formed in two joint judgments (French CJ, Kiefel and Bell JJ, and Nettle and Gordon JJ) and a single judgment (Keane J), with Gageler J dissenting.

French CJ, Kiefel and Bell JJ concluded that div 4AA did not confer a penal or punitive power to detain and otherwise did not answer question (1)(a), and further concluded that the power did not undermine the institutional integrity of the NT courts. The judges construed the detention powers under s 133AB as conferring only a discretionary power exercisable after a paperless arrest only if that arrest relates to an infringement notice offence, and concluded that s 133AB does not confer unfettered discretion to hold people for up to four hours: at [34]. This restriction, combined with div 4AA’s use being constrained by a number of purposes (such as preservation of public order, see at [35]), meant that div 4AA did not disclose a punitive purpose, and it could not be lawfully used for a punitive purpose (see [36]–[38]). In rejecting the plaintiffs’ Kable arguments, French CJ, Kiefel and Bell JJ rejected the plaintiffs’ apparent suggestion that div 4AA did not impose a duty to bring an arrested person before a justice of the peace or court as soon as practicable if the person was not released unconditionally or on bail, and thus held that the relationship between the custodial process and the judicial process under div 4AA was not materially different from that under the ordinary arrest process in s 123: see at [43].

Nettle and Gordon JJ answered questions (1)(a) and (1)(b) as ‘no’. Nettle and Gordon JJ construed the power in s 133AB(2) as a power that arises simultaneously with the duty to bring the person before a justice of the peace or court as soon as is practicable unless the person is granted bail or released, provided for in s 137(1): ‘up to four hours’ imposes an upper time limit on the exercise of the duty under s 137, and div 4AA specifically elaborates that general power and duty: at [214] (and see justifications for this reading at [215]–[229]). Consequently, any detention for longer than required to render it practicable to release the person unconditionally, with an infringement notice, or on bail, or take the person before a justice of the peace or a court would be unlawful: [231]. Nettle and Gordon JJ also dismissed the plaintiffs’ constitutional arguments that the powers were penal or punitive because on their construction div 4AA does not permit detention for longer than is reasonably necessary to bring the person before a justice of the peace or a court and thus falls into the arrest and custody exception in Chu Kheng Lim v Minister for Immigration [1992] HCA 64 (at [235]–[237]) and similarly does not contravene Kable because it does not usurp or interfere with judicial power once an arrested person is brought before a justice of the peace or a court (at [238]–[239]).

Keane J held that div 4AA was not invalid, irrespective of whether it conferred a penal or punitive power to detain, because it was not beyond the powers of the NT Legislative Assembly and does not undermine the institutional integrity of the NT courts. Keane J noted that while the Court should not ordinarily determine questions of constitutional validity where the law properly construed does not have the operation and effect contended for, because in this matter the resolution of the constitutional issues is ‘on any view, straightforward’ (at [149]) and the ‘concrete’ disagreement between the parties on the construction of div 4AA was not entirely clear (see [151]–[153]), it would be best to avoid characterising the power and consider instead the constitutional issues first. Keane J rejected the plaintiffs’ first contention that the NT Legislative Assembly’s powers were limited by the Commonwealth separation of powers and declined to re-open Kruger v Commonwealth [1997] HCA 27 (see [155]–[171]), and the second contention that NT courts always and only exercise federal jurisdiction: those courts are creatures of the NT Legislative Assembly and not the  Commonwealth Parliament (see [172]–[181]). In rejecting the Kable arguments, Keane J held that div 4AA is not directed at the courts: it does not ‘enlist’ the courts in exercising an executive power, or add to or deprive them of judicial powers, or direct it in the exercise of its functions (see [182]–[188]).

Gageler J, in dissent, would have answered question (1) affirmatively and concluded that div 4AA was invalid on the basis of the Kable arguments. Noting that the Court should not depart from ordinary principles of statutory construction to ensure constitutional validity (see [76]–[78]), Gageler J construed div 4AA as allowing the police to detain a person arrested for an infringement notice offence for a maximum of up to four hours, with the period of detention left to the discretion of the police (at [91]) and while it is not entirely unconfined, it is undefined (at [92]). The s 137 requirement of release or bringing the person before a justice of the peace or court only comes into operation on the expiry of the period of detention and only when the police decide to deal with the person under s 133AB(3)(d): see at [84]ff. The duration of a detention under div 4AA was neither reasonably necessary to effect the statutory purpose of the detention, nor capable of being objectively determined by a court at any time: it allows detention for a maximum of four hours at the discretion of the police, and results from a member of the police force acting as a judge rather than accuser (see [99]–[102]). Consequently, div 4AA authorises a punitive form of detention. Gageler J rejected the plaintiffs’ arguments that the NT Legislative Assembly was constrained by the Commonwealth separation of powers (see at [104]–[118]). But Gageler J accepted that it infringed the integrity of NT courts. Division 4AA prevents those courts being brought into the further processes at the end of the period of detention because regardless of the option chosen by the police, the person will have already been punished by executive detention: the NT courts ‘are thereby made support players in a scheme the purpose of which is to facilitate punitive executive detention’ which is ‘antithetical to their status as institutions established for the administration of justice’: [134].

The proceedings will be remitted to a single Justice of the Court for further directions.