Overlaps and Intersections in Theory and in Practice – Public Law and Criminal Law in Australia book forum
Chris Carr SC and Minh-Quan Nguyen provide the third post in our book forum on Nicholas Petrie and Julian R Murphy’s edited collection Public Law and Criminal Law in Australia: Overlap, Intersection and Inconsistency. To see all posts, please click here.
Chris Carr SC and Minh-Quan Nguyen
19.12.2025
Public Law and Criminal Law in Australia deals with overlaps and intersections, in more ways than one. For one thing, the volume methodically interrogates the relationship between the fields of ‘public law’ and ‘criminal law’, highlighting the connections and commonalities (and some tensions) between them. For another thing, the volume sits at the intersection of scholarship and practice, as reflected in the varied backgrounds of its editors and contributors.
We wish to focus on two contributions that the volume makes to the understanding of criminal law and public law. First, it provides a theoretical treatment, and practical illustrations, of how criminal law forms part of Australian public law. Second, it highlights that criminal law serves as an important theatre for ongoing debates about public law doctrine and the development of that wider body of law. In both respects, it is of real practical significance to those who practise in these fields.
Situating criminal law within public law
In his introductory chapter, Dr Julian Murphy identifies public law as ‘the system of primary and secondary rules concerned with the regulation of state power to serve public purposes and to protect individual rights and interests’. Using that conception as a departure point, he identifies criminal law as a ‘distinctive sub-field’ of public law. He argues, persuasively, that a criminal trial is designed:
… to hold individual members of society accountable to that society for conduct considered to be contrary to the society’s norms. This is the overriding public function of the criminal trial … [and] the rules of criminal procedure have developed … to recognise that function but also to discipline the state power deployed in the process.
The contention that criminal law should be understood as a sub-field of public law is not just a taxonomical point; it has doctrinal implications. Consider, for example, the observations of Gageler J in Garlett v Western Australia(2022) 277 CLR 1 at 49 [133], when — in the course of exploring the constitutional constraints on executive detention — his Honour stressed the importance of viewing the functions of criminal law in the context of the constitutional relationship between the individual and the state:
That substantive constitutional significance of consigning the function of adjudging and punishing criminal guilt exclusively to the judicial branch of government is the central contribution that our common law system of adversarial trial has made to establishing and maintaining the relationship between the individual and the state within our inherited conception of the rule of law. Although rarely articulated, and all too readily overlooked, it lies at the heart of our system of government.
Other chapters provide useful illustrations of how the primary and secondary rules of Australian criminal law interact with, and form a subset of, the primary and secondary rules that make up the broader field of Australian public law. For example, in chapter 8 (‘The Intersection of the Racial Discrimination Act and the Criminal Law’), Saul Holt KC and Rachael Taylor focus on the primary (or substantive) rules of criminal law, and address how the Racial Discrimination Act 1975 (Cth) affects the capacity of State Parliaments to regulate conduct through criminal laws. In chapter 6 (‘Are independent public prosecutors bound by human rights law?’), Professor Jeremy Gans considers secondary (or procedural) rules, and whether the Charter of Human Rights and Responsibilities Act 2006 (Vic) (the Charter) applies to the exercise of state power to conduct criminal prosecutions.
Further illustrations of criminal law forming part of the framework of public law may be readily identified. Take, for instance, the doctrine of public interest immunity, which requires a court to prevent disclosure in judicial proceedings of information the release of which would be deleterious to the public interest. As Lord Pearson explained in Rogers v Home Secretary [1973] AC 388 at 406:
The Court has to balance the detriment to the public interest on the administrative or executive side, which would result from the disclosure of the document or information, against the detriment to the public interest on the judicial side, which would result from the non-disclosure of a document or information which is relevant to an issue in legal proceedings.
Public interest immunity is undoubtedly a doctrine of public law. It is also firmly established as part of the secondary rules of the criminal law. In criminal proceedings, what is weighed against ‘the public interest on the administrative or executive side’ is the public interest in enabling a defendant to ‘establish all such facts and matters … as may assist in securing a favourable outcome to the proceedings’: Jarvie v Magistrates’ Court of Victoria [1995] 1 VR 84 at 88. The doctrine thus involves a direct collision between the broader interests of the state and the narrower interests of the accused. In the criminal context, the outcome of that collision is shaped by the values of the criminal law, and in particular the overriding need for a fair trial of an accused; hence, ‘once it is demonstrated that there is good reason to think that non‑disclosure may result in substantial prejudice to the accused, the balance has been shown to incline in [their] favour’: Jarvie [1995] 1 VR 84 at 90. And, in an ‘appropriate case’, where the requirement for a fair trial comes into conflict with an overwhelming public interest in non-disclosure, the conflict may require the prosecution to be withdrawn or the court to stay the proceedings: AB v CD [2017] VSCA 338 at [66]. The doctrine directly constrains public power and seeks thereby to maintain the balance between the interests of the state and the individual.
Criminal law and the development of public law doctrine
The chapters in this volume do not merely situate criminal law within the field of public law. They also highlight the role that Australian criminal law plays as a forum for expounding public law principles, and testing the boundaries of those principles.
For example, much of the High Court’s jurisprudence on the implied freedom of political communication has occurred in the context of cases dealing with criminal offences; many of these are adverted to in Julia Wang’s chapter on the criminalisation of public protest. Meanwhile, two other chapters squarely focus on the role of administrative law in the criminal sphere. In chapter 5, Emrys Nekvapil SC and Bryony Seignior address the relationship between judicial review and criminal proceedings, examining both the exercise of supervisory jurisdiction by superior courts and debates about the extent to which ‘collateral attacks’ on administrative decision-making may be permitted in proceedings other than for judicial review. And, as noted above, Jeremy Gans in chapter 6 examines whether the Director of Public Prosecutions and Crown prosecutors are ‘public authorities’ bound by the Charter.
The topic examined by Gans clearly has salience beyond the context of the Charter — in part because of the comparable human rights instruments that exist in Queensland and the Australian Capital Territory, but more generally because the considerations that inform the ‘public authority’ question are relevant to broader, and recently re-enlivened, debates about where prosecutorial functions fit within the framework of administrative law doctrine. As Gans notes, Australian courts have been chary of the notion that prosecutorial decision-making might be subject to judicial scrutiny. A notable instance of that approach was the reasoning of a majority of the High Court in Maxwell v The Queen (1996) 184 CLR 501, which concerned whether a trial judge had power to reject a plea that had been accepted by the prosecution. Justices Gaudron and Gummow there posited that ‘certain decisions involved in the prosecution process are, of their nature, insusceptible of judicial review’, which was to be traced to the importance of maintaining ‘[t]he integrity of the judicial process’; the concern being that judicial independence and impartiality would be undermined if courts were to become ‘concerned with’ prosecutorial decision‑making: at 534. The defensibility of these statements — both descriptively and normatively — has been the subject of scholarly (and occasionally judicial) comment and scrutiny.
The debate over the relationship between judicial review and prosecutorial decision‑making was re‑awakened in Harkness v Banks (No 2) [2024] VSC 709, a decision of the Supreme Court of Victoria (to which Nekvapil and Seignior briefly refer). The plaintiff there sought judicial review of a decision by the Director of Public Prosecutions, exercising the statutory power in s 22(1)(b)(ii) of the Public Prosecutions Act 1994 (Vic), to take over a private prosecution instituted in the Magistrates’ Court of Victoria and withdraw all charges. The matter was listed for the hearing of the ‘constitutional question’ of whether the Director’s decision to withdraw the criminal charges was susceptible of judicial review for jurisdictional error. The Director’s stance was that exercises of prosecutorial discretion, including the decision in that case, were in general insusceptible of judicial review; described in submissions as the ‘principle of unreviewability’. Consistently with Maxwell, that principle was said to be supported by constitutional considerations (in particular, the separation of powers and the institutional integrity of courts).
Justice Richards accepted the Director’s submission that, as a matter of authority, the constitutional question was to be answered in the negative. However, her Honour (after setting out in detail the forceful submissions to the contrary advanced by counsel appearing as amici curiae) proposed several reasons to doubt the principled correctness of that result. Underpinning those reasons was a concern that the result was at odds with now‑established understandings of the constitutionally entrenched supervisory jurisdiction of State Supreme Courts. As well as voicing the concern that the ‘principle of unreviewability’ might render the Director an ‘island of power immune from supervision and restraint’ (at [77]), Richards J implicitly characterised the ‘principle of unreviewability’ as being itself an increasingly anomalous island in the context of modern understandings of the scope of judicial review. We note that Richards J’s judgment will not be the last word on the matter: an application for leave to appeal against the judgment is pending in the Court of Appeal and expected to be heard in 2026.
Concluding observations
Public Law and Criminal Law in Australia points to the significance of criminal law as a field in which public law principles have been and continue to be expounded, tested and developed. From a practical standpoint, this highlights the utility and importance of ‘public lawyers’ engaging with criminal law and ‘criminal lawyers’ engaging with public law. As Edelman and Steward JJ reminded us in CCIG Investments Pty Ltd v Schokman(2023) 278 CLR 165 at 185 [48], ‘the reason ... “stovepipe” lawyers cannot move confidently from one area of the law to another is that nobody has shown them the map’. Seeing the whole map allows practitioners to identify relevant issues and mount novel arguments about the development of the law. To give one more example, matters involving the application of criminal statutes can raise important questions of construction: see, for instance, the questions raised about the operation of interpretive provisions in the Charter in Momcilovic v The Queen (2011) 245 CLR 1 and Director of Public Prosecutions v Smith (2024) 98 ALJR 1163 (and see Kent Blore’s discussion of the latter case). An awareness how the fields relate to one another assists in ensuring that such issues are identified and interrogated, rather than being overlooked or remaining at ‘the periphery of the argument’ (cf Minogue v Victoria (2018) 264 CLR 252 at 278 [80] (Gageler J)).
More routinely, practitioners who site the criminal law within the larger public law map are able to see additional pathways towards a destination. The modern criminal investigation takes place in a land of burgeoning but regulated state power. Standing proud at the front of the modern investigator’s armoury are powers of arrest, surveillance devices, telephone intercepts, search warrants, forensic procedures and compulsory examinations. All are governed by administrative law principles. ‘Criminal lawyers’ who see the larger map are able to deploy the tools developed in public law, most notably the concept of jurisdictional error, to ensure that these powers are kept within their proper limits. Correlatively, ‘public lawyers’ who site ‘criminal law’ within their field are able to conceptualise the limits of state power by reference to its rawest and most brutal form.
The chapters in Public Law and Criminal Law in Australia illustrate the value of careful reflection on the relationship between public law and criminal law. The various authors rigorously address live issues and debates which are of ongoing practical importance. The volume thereby provides a source of critical analysis, ideas and inspiration for those working in the fields. As Geoffrey Nettle observes in his foreword, the volume is ‘likely to be of real assistance in the application and development of public law and criminal law’.
Chris Carr SC practises in criminal and administrative law. His practice has a particular focus on appellate advocacy and judicial review. He is the Chair of the Victorian Criminal Bar Association.
Minh-Quan Nguyen is a barrister at the Victorian Bar. He practises mainly in public and commercial law, and has appeared in significant cases dealing with constitutional law, administrative law and criminal law. Previously, he was counsel assisting the Solicitor‑General for Victoria and an associate at the High Court of Australia.
Suggested citation: Chris Carr and Minh-Quan Nguyen, ‘Overlaps and Intersections in Theory and in Practice – Public Law and Criminal Law in Australia book forum’ (19 December 2025) <https://www.auspublaw.org/blog/2025/12/overlaps-and-intersections-in-theory-and-in-practice-public-law-and-criminal-law-in-australia-book-forum>