Book review: “Law as a Leap of Faith” by John Gardner

A hankering for some difficult reading led me to click on "buy now" for the hard cover edition of "Law as a Leap of Faith" by John Gardner. He is Professor of Jurisprudence at Oxford.

I haven't had much of a look at jurisprudence since I was a law student. I had found HLA Hart's celebrated "The Concept of Law" and "Punishment and Responsibility" among the most awfully written, tedious and incomprehensible books I had ever been told I should read. My still largely-unread copies, on my shelves as I write, were lent to me all those decades ago, and the lender hasn't asked for them back.

I wanted the hard copy of Gardner's book because I knew I would be scrawling all over it as I struggled to grasp its meaning. I call him "Gardner" in imitation of the academics' habit of referring to each other by surname only, as if they were schoolboys or Great People like Socrates or Beethoven. I would rather call him John, as he seems a pleasant sort of chap, if his lecture in Auckland on reasonableness, which can be heard here, is any indication. But then people would wonder why I didn't call Hart "Herbie", and Dworkin "Ronnie" (which is what Gardner has called him: p 274, n7).

As a practising lawyer I have been content with what Gardner says (p 273) most lawyers like: the Austinian view of laws as commands; that is the nature of laws and that is all we need to know about that. I say "laws" because lawyers are concerned with "the" law, whereas legal philosophers tend to be concerned with "law" as a genre (p 184).

So, what does Gardner say about his approach as a legal philosopher? In his Preface he describes it in this way:

"Philosophy is not the art of compiling as many little thoughts as possible into as few big thoughts as possible, but the art of wearing every thought down to its rightful little size and then keeping it in its rightful little place. So the main mission of this book, as I see it, is unbundling: separating out disparate thoughts that have often been regarded, mistakenly, as part of some package deal."

There are 11 chapters, mostly based on previously published work or lectures. The first few chapters are, I thought, quite hard going, and it is eventually comforting to have Gardner admit in Chapter 9 that he finds some of the writing by his fellow philosophers difficult to follow (eg p 236: "Hart's treatment of morality ... is a mess") or simply wrong (eg pp 184-185 referring to Dworkin's critique of Hart's criteria for a legal system). Indeed in this book nearly all of the references to Dworkin are to what Gardner considers to be his errors.

Some initial difficulties arise from the technical terminology, which is not explained in a glossary. You need to quickly get used to thinking about "norms". Norms are, so it seems to me now, standards or rules of behaviour. Not an enormous insight, I admit, as this is pretty much the dictionary definition. They are not necessarily legal in nature, and there are lots of other sorts of norms: moral norms (and there is a process whereby these can become legal norms too), etiquette, rules of sports, rules of associations, etc (see p 296). Another important term is "legality". Although he seems to equate this with the rule of law at p viii of the Preface, Gardner uses legality more widely to refer to the quality a norm has when it is a legal norm. So Chapter 7, "The Legality of Law" is an inquiry into what is needed for a norm to be a legal norm.

I thought on first reading that there was a dreadful logical mistake on p 140, but, thank goodness, a hundred pages later it became clear that this was not so, thanks to Gardner's style becoming more reader-friendly (which is odd because the passage on p 140 was written in 2012, and that on p 240 in 1999: is he getting less clear as he grows up?) Could be me getting more used to the material as I read through from beginning to end. The chapters can be read in various orders, and the Preface helpfully provides what amounts to a roadmap for the book.

Following Hart (and Gardner tends to follow and improve upon Hart), an inquiry into the nature of law begins, not by analysing laws, but by considering what is required for a system of norms to be a legal system (p 179). I won't spoil your fun by telling you all of them, but very important is the requirement that the actions of the norm-applying officials can sometimes result in the making of more legal norms (p 180). Important too, and not noticed by Hart, is the legal system's claim to be supreme among the institutionalised normative systems (p 278). Legal norms are products of their legal system and encompass laws and rulings; the laws are of general application and the rulings apply to the parties in a case. Consideration of a ruling or a line of rulings in later cases may eventually result in development of a new law (eg p 185, 186-188).

Most laws are consistent with moral norms, so it is usually morally right for judges to apply legal norms. But there can be immoral laws, and this raises the question ("puzzle" p 189) of how officials become morally required to apply legal norms. Gardner calls this the main puzzle about law, and he says Hart was mistaken in saying that there is a generalised moral value in following laws (p 189). No, but officials are required to follow laws because a characteristic of legality is the binding power of the oaths taken by the officials, their contractual obligations, and the semi-voluntary obligations of their professions. Thus a judge must, in arriving at a determination, put justice above other moral imperatives such as kindness and prudence (191-192).

Laws have an inner morality, in a sense that reflects the quality of the means by which they serve their ends; it is preferable to describe laws as modal (concerned with means) rather than as procedural or substantive (pp 202, 206-207). Variations in the inner morality of different laws mean that not all laws live up to the ideals of legality. Hart thought there are two concepts of law, the wider positive law (law that is law because it satisfies the formal means by which it was made, so is correctly posited) and the narrower genre of law that lives up to an appropriate moral ideal (pp 193-194). Gardner, however, prefers to say that this second concept is unnecessary, and that it should be sufficient to say that there are specialised moral norms that are "partly constitutive of law as a genre" (p 194). Examples are the norms that law should be prospective (rather than retrospective in application), open, general, and with qualities such as these they constitute a distinctive ideal of legality, known as the rule of law.

But it's not just the internal morality of rules that determines compliance with the rule of law, but it is also the internal morality of the arrangements for upholding their purported application (pp 209-210). Gardner refers to arrangements identified by Raz: a robustly independent judiciary, affordable and easy access to the courts, effective judicial review of executive action, effective appeals, dispassionate professionalism among police, prosecutors, and other enforcement officials, strong respect for procedural propriety, and the giving of reasons for decisions. Gardner points out that it is a violation of the rule of law for a judge to declare a rule but not to apply it, or for a judge to deny there is a rule and to say a case is decided "on its particular facts" (p 210).

I should add that you might compare these requirements of the rule of law to those advocated by Tom Bingham in "The Rule of Law" (2010); he included the norm that the law must afford adequate protection of fundamental human rights, acknowledging in his Chapter 7 that this was not a principle which would be universally accepted as embraced within the rule of law, and he referred to the version of the rule of law put forward by Raz as being "close to what some economists have called a 'thin' definition of the rule of law". Bingham noted that the Universal Declaration of Human Rights and later international instruments have linked the protection of human rights to the rule of law, as has the European Court of Human Rights (citing Engel v The Netherlands (No 1) (1976) 1 EHRR 647, 672, para 69, and Golder v United Kingdom (1975) 1 EHRR 524, 589, para 34).

I found Gardner's discussion of justice in Chapter 10 particularly helpful. He reminds us that justice is proportionality in allocation of goods and ills (p 242). Justice is not peculiar to legal systems and questions of justice arise whether or not there are rules (p 256). But in a legal system the law is only subject to justice at the point where the benefits and burdens come to be allocated. (I interpose: this does not mean only at the end of a case, as judges often have to make decisions during a trial – for example by permitting or preventing some forms of cross-examination – by applying the criterion of the interests of justice.) There are competing moral norms, such as humanity, that a legal system can give priority to, but a court ought to be just above all (pp 244, 259).

Well I don't want to spoil your enjoyment of "Law as a Leap of Faith" by going through it all and revealing its arguments. But in wondering how philosophers work you might ask how all these (what Gardner would call) little thoughts fit into their rightful little places. You may find yourself making a diagram, if like me you are the sort of person who is assisted by images (click on image for full diagram and key).

I keep not depriving you of enjoyment to save myself the task of setting it all out, and also to assist in the accumulation of Gardner's royalties. Dan Brown is safe in the popularity stakes, but "Law as a Leap of Faith" has an excitement of its own that repays any effort needed to adjust to the technical prose.

Rational sentencing

In Elias v The Queen [2013] HCA 31 (27 June 2013) a common law principle of sentencing was clarified: a sentence is determined in relation to the offence for which the offender was convicted, it being irrelevant that another offence with a different maximum penalty could have been charged on the same facts.

Therefore it is wrong for a judge to reduce, or to increase, a sentence because a different maximum penalty was provided for another offence that could have been charged.

If the judge were to be distracted by referring to sentences for other offences, the consistency of sentencing for the actual offence for which the offender was convicted could be endangered. The Court referred [28]-[30] to its decision on consistency in Hili v The Queen (discussed here on 10 December 2010).

The prosecutor's choice of charge is not a fetter on the sentencing court's discretion, because a wide range of considerations, including the maximum penalty for the offence charged, go in to determining the final sentence. The maximum penalty is merely a yardstick provided by the legislature, and consideration of it may not necessarily play a decisive role in the final determination. Justice is individualised at sentencing and judges have a wide discretion, unconstrained by the maximum penalty [26].

The judge must not interfere with the choice of charge, and any abuse of the prosecutor's discretion alleged by the defendant can be the subject of a pre-plea application [35]. The separation of the functions of judge and prosecutor makes it just as inappropriate to sentence on the basis that the judge thinks a less serious charge should have been laid, as that it should have been a more serious charge [34].

This is all said in the context of the relevant sentencing legislation, the Sentencing Act 1991 [Vic]. Things may be different in your jurisdiction, which may give rise to questions about how rational a different regime may be if it permits the taking into account of the maximum penalties prescribed for other types of offences. The Sentencing Act 2002 [NZ], s 8(b) does exactly that. Does it thereby introduce risks of inconsistencies, does it abolish fetters, and does it blur the distinction between judge and prosecutor?

Criminal process, compulsory interrogation, statutory construction, and the right to a fair trial

When might a statute impliedly compromise fundamental rights connected with criminal proceedings? This issue was at the heart of X7 v Australian Crime Commission [2013] HCA 29 (26 June 2013). The Court split 3-2.

The primary question for the Court was, put broadly, whether provisions (Div 2 of Part II of the Australian Crime Commission Act 2002(C'th)) that empowered an examiner to interrogate a person, extended to questioning a person who was subject to criminal proceedings. If the provisions did have that effect, a further question of their constitutionality would arise. The majority held that the provisions did not authorise examination of a person who was subject to criminal proceedings, so that the constitutional question did not arise.

The "right to silence" – not mentioned in the relevant legislation - could be thought of as a general expression, encompassing the right of a defendant not to answer questions put by the police or other persons in authority, and the right of a defendant not to be compelled to give evidence or to assist the prosecution in discharging its onus and burden of proof. That is broadly how the minority, French CJ and Crennan J, described the defendant's rights at issue here [39]-42], although they also mentioned – and recognised the importance of - the defendant's right to a fair trial [37]-[38].

The majority, Hayne and Bell JJ jointly, with Kiefel J concurring, drew from the accusatorial nature of a criminal trial the "right to silence" and the related "privilege against self-incrimination", applicable to defendants and suspects respectively [100]-[102], observing that although historically of relatively recent origin they are fundamental features of the accusatorial system of criminal justice [100], [102].

Whether a statute might, by necessary implication, compromise those features of the accusatorial process, depends on how much weight one is prepared to give them. The majority held these features are out of reach of implied compromise. They held that such an alteration would need to be made "clearly by express words or by necessary intendment" [118]-[119], or – Kiefel J – "must be expressed with irresistible clearness" [158].

The minority said [43] that a compromise of one of the two aspects of the right to silence that it had identified, while the other was left intact, was a legislative balance struck here between competing public and private interests. The minority found that a legislative intent to achieve this balance could be implied from the legislative history and the context of the provision in the overall Act including its provisions that protect defendants [24]-[30], [52]-[61].

Recognising that a trial must be fair, and that compelling a defendant to answer questions or to give opportunities for the obtaining of derivative evidence, could not be reconciled with a fair trial [54], the minority pointed to the existence of powers to suppress publication of evidence, and to control who was aware of the evidence, in order to protect the fairness of a trial, calling them safeguards that are capable of preventing an unfair burden on a defendant [57]. A trial judge's powers to prevent an abuse of process and to punish for contempt are also available to protect the fairness of proceedings [38], [59].

The majority denied that it was basing its reasoning on considerations of fairness, saying that the determinative question in this case was one of construction of the legislation [90]. Recognising that the requirement to answer questions after being charged would fundamentally alter the accusatorial process – which includes pre-trial inquiries and investigations (Kiefel J at [160]) - because the defendant would have to choose at trial a course in the light of any self-incriminatory answers that may have been compelled, and that this would prejudice the conduct of the defence [124], it held that such a result could only be achieved by clear words or necessary intent [125], which were absent in the legislation here [142].

Looking at this case in the round, one could say that, despite the majority's disavowal of fairness as the decisive criterion, the difference between the judges illustrates inconsistent perceptions of what "a fair trial" means. For the majority a fair trial is one in which the defendant may make decisions as to the conduct of the defence without being constrained by information he was compelled to provide to officials, or by information obtained as a consequence of his being under that compulsion. The minority, referring in general terms to the judge's powers to prevent abuse of process [38], only say that prosecutorial reliance on compelled information would be unfair [54], and they do not say how a judge would determine that the prosecution had obtained "an unfair forensic advantage" [59].

Current exploration suggests that an element of a fair trial is impartial determination of the facts, and impartial here means both without bias and without inappropriate weight being given to any item of evidence. Constraints on the presentation of a defence, arising from compulsory interrogation, endanger the appropriateness of the weighing of the evidence by the fact-finder, and thereby endanger the fairness of the trial.

Legislated schemes for compulsory interrogation vary, as one would expect, and can include a right to claim privilege against self-incrimination coupled with a right to refuse to answer a question (subject to judicial review), as does s 138 of the Search and Surveillance Act 2012 [NZ], although in that regime failure to answer questions outside of a claim of privilege appears to be an offence: s 173. In X7 the defendant was told he had a privilege against self-incrimination but he did not have an associated right to refuse to answer questions [12]-[13]. He subsequently claimed privilege and refused to answer questions, which was an offence.

Dissent on the Fifth Amendment, helpful judgment writing, and the permanence of grades

Pre-trial, non-custodial, silence by a voluntarily cooperating person, during police questioning, was the subject of a prosecutor's invitation to the jury to draw an inference adverse to that person who was subsequently the defendant, in Salinas v Texas USSC No 12-246, 17 June 2013.

The intricacies of the law on the Fifth Amendment can be left with people in the United States of America, although they are not particularly difficult. Surprising it is, therefore, to see the Court split: the majority, comprised of a plurality of Alito J, joined by Roberts CJ, and Kennedy J, with a concurring opinion by Thomas J, joined by Scalia J, appear to have all agreed that the defendant had not invoked the Fifth Amendment, and that without invocation the prosecutor was free at trial to invite an adverse inference from the defendant's silence. Thomas and Scalia JJ did not discuss invocation because they considered that a more direct solution was to ask whether the prosecutor's comments were in breach of the Fifth Amendment by compelling the defendant to give evidence, holding that the comments did not. But they did not disagree with the plurality reasoning, as Thomas J says in his first paragraph: " ... even if he [the defendant] had invoked the privilege ...".

The minority, Breyer J joined by Ginsburg, Sotomayor and Kagan JJ, held that express invocation of the Fifth Amendment is not required, and that invocation can be inferred from the circumstances, with it also being relevant to ask whether there is good reason to excuse the individual from referring to the Fifth Amendment, such as "inherent penalisation simply by answering."

The case makes me think of two general matters:

The organisation of the opinions is helpful to readers and could be followed by other appellate courts. The dissenters refer to points in the majority's reasoning with which they disagree, and they state why. Then – and this is the significant point – the majority in footnotes refer to the minority's points of criticism and answer them. The reader is left with a complete account of the debate, rather than having points left hanging.

The other thing is about the marking of student's examination papers. What if a contentious issue, such as that in Salinas, was the subject of an examination question before it was determined by the Supreme Court? Some students, like some of the justices of the Court, would reason to one conclusion, others to the opposite conclusion. The ones who agreed with their teacher's opinion would perhaps – indeed, would probably – get better grades that the others. But the teacher might be wrong. Once the teacher's error is revealed by a final determination of the highest appeal court, should the examination grades be re-assessed? The grades may have been very important for the students, denying some of them scholarships or employment prospects. Undergraduates and graduates are usually members of a university, and perhaps their university should have a duty of care to its members to get its grading right and to correct errors whenever they may be revealed. Why should an incorrectly marked examination paper produce a permanent grade?

When trials do not have to be “according to law”

Does a trial always have to be "according to law"? No.

Being in accordance with the law is not a sufficient condition for a lawful conviction. If an appellate court finds, in the facts of the case before it, circumstances that should amount to a new defence, and if the court then proceeds to recognise and define that new defence, we would expect the court to apply the newly recognised defence to the appeal before it and to allow the appeal against conviction. In such a case the trial was not according to law, in the sense that the defence was not applied, even though at the time of the trial the defence was not recognised and the trial was according to the law as it was then understood to be. Here, the trial although according to law, was defective.

Neither is being in accordance with the law a necessary condition for a lawful conviction. If an appellate court decides that a previously recognised defence has been incompletely defined, and that now, because of the circumstances revealed in the appeal now being considered, an additional matter is an ingredient of the defence, what should we expect the court to do? Should it apply the newly recognised ingredient to the present case and dismiss the appeal against conviction because at trial the defence had not included the new ingredient? Or should it say that the new law applies to future trials, but this one is to be judged according to the old law? Usually, where the substantive law is changed, a defendant has the benefit of whichever version is more favourable to him. So we would expect the appellate court to say that the old law applied to this trial. If the court does the opposite, and says that the new law applied to this trial even though it was then unknown, the court is saying that the trial could result in a valid conviction even though it was not in accordance with the law as it was at the time of the trial. This latter is what happened in R v Gauthier, 2013 SCC 32 (7 June 2013).

At issue in Gautier was whether there had been sufficient evidence at trial to give a defence of withdrawal from participation (what Canadians call abandonment) an air of reality sufficient to require it to be left to the jury. This turned on what the ingredients of the defence were. Fish J, dissenting, shows that the majority have added a new ingredient in relation to aiders and abettors – the taking of reasonable steps to negative the effect of participation – to those that had previously been identified, namely an intention to withdraw, communicated unequivocally to the other participants. Indeed, the majority do not conceal the development of the defence that they are now undertaking: [38], [49]-[50].

The majority applied the new ingredient of the defence to the trial it was considering, and held that there was insufficient evidence of the taking of reasonable steps to negative participation: [62]-[64].

This means that the trial was not in accordance with the law that the Supreme Court was now recognising, but which was unknown at the time of the trial, yet the trial resulted in a valid conviction.

The rule of law requires that the law be ascertainable. This should mean that a person should be tried according to the law as it was ascertainable at the time of the alleged offending. See, for example, PGA v The Queen [2012] HCA 21, discussed here on 30 May 2012 (and referring to Christian v R (The Pitcairn Islands) [2006] UKPC 47 at [24], R v Rimmington [2005] UKHL 63 especially at [33], and Rogers v Tennessee, 532 U.S. 451 (2001)).

Another aspect of Gauthier is reliance on inconsistent defences. There is no rule against this, and all defences, whether raised by the defendant or not, for which there is sufficient foundation in the evidence, should be considered: majority at [34], Fish J agreeing at [97]-[99]. A "sufficient foundation" exists if there is evidence to give the proposed defence "an air of reality", in the sense that the evidence is reasonably capable of supporting the inferences necessary for the defence to succeed: majority at [60], and Fish J at [100] ("some evidence upon which a properly instructed jury could form a reasonable doubt").

Modifying, or applying, the law

Appellate courts sometimes have to extend, modify, or reshape existing law to recognise matters of public policy. More usually, they merely apply existing law. These contrasting roles are illustrated in two recent decisions of the Supreme Court of the United Kingdom.

When a statute is silent on the matter, how is a court to decide whether evidence should be ruled inadmissible because the way it was obtained departed from prescribed procedures? One criterion can be whether the error can be corrected by further investigation. If the test that was done destroyed a sample that cannot be replaced, the result of the test should be inadmissible.

This criterion was mentioned in Public Prosecution Service v McKee (Northern Ireland) [2013] UKSC 32 (22 May 2013). The difference between an unrepeatable test and a repeatable one is discussed at [13]-[15]: a sample collected by a breathalyser device is unrepeatable unless an error is immediately apparent (the machine fails to work properly), so if it is later discovered that an unapproved device was used the result is inadmissible. But if, as in this case, an unapproved electronic device was used to read the defendant's fingerprint, the error could easily be checked at any time by the defendant providing another sample for analysis by, for example, an independent expert. Where opportunities exist for checking a result by repeated testing, an error in the initial procedure should not require the initial result to be held inadmissible.

Well, one might wonder what has happened to the burden of proof here. The policy behind this shift is indicated at [17], and it seems that if the fingerprint was inadmissible here the implications for other cases would have been unacceptable, with limitations on the ability of the police to prove crimes and on the opportunities for defendants to exculpate themselves.

But still. Was the executive wasting its time when it made an Order for the prescribing of procedures for electronic reading of fingerprints? Has the prosecutor in effect asked the Supreme Court to repeal the procedures that were eventually prescribed? Could the Northern Ireland police in the relevant period (1 March 2007 to 12 January 2010) have used any fingerprint reading device they wished to? Apparently yes, for there was no approved device for the first two years of that period [3]. Obviously there was great pressure on the Court to find a solution and avoid the need for retrospective legislation.

Another recent decision of the Supreme Court of the United Kingdom finds the Court exercising its less adventurous function, that of applying established law, on two matters: when, for the purpose of measuring delay, is a person charged with an offence, and when does apparent bias exist arising from judicial comments adverse to the defendant: O'Neill v Her Majesty's Advocate (No 2) (Scotland) [2013] UKSC 36 (13 June 2013).

The law on when, for this purpose, a person is charged was established in Ambrose v Harris, Procurator Fiscal, Oban (Scotland) [2011] UKSC 43 (6 October 2011), discussed here on 7 October 2011. On the facts of O'Neill the defendants were well aware, at the time they now contended was when they were charged, that the police did not intend to charge them. They were like the defendant in Cadder v HM Advocate [2010] UKSC 43, discussed here, but without reference to the facts, on 27 October 2010, and absence of access to legal advice at that time was irrelevant because the defendant's knew their rights and exercised them [35]. So the first interviews, years before the later ones which was when the defendants were charged, was not the one from which time ran for the purpose of determining whether there was unreasonable delay in bringing them to trial.

As to apparent bias, in O'Neill there were two trials: the first involving alleged sexual abuse and the second, the following week, murder. After the jury at the first trial convicted them the judge said to the defendants: "...it is clear that you are both evil, determined, manipulative and predatory paedophiles of the worst sort." The same judge presided at the second trial. The Supreme Court referred to the established law on apparent bias [47], [49], including Helow v Secretary of State for the Home Department [2008] UKHL 62 (22 October 2008), discussed here on 23 October 2008, and held that here the judge had done no more than it was his duty to do [53]-[55]. The comments were not gratuitous and were within the scope of the proper performance of the judge's duties, as a risk assessment was required and the defendants were entitled to some indication of what sentence they might expect. Importantly, no-one involved in the trials raised at the relevant times any objection to the judge's conduct:

"[56] ... the fair-minded and informed observer would take account of the fact that it did not seem to occur to those with the most obvious interest to do so, or their advisors, that the judge had trespassed beyond the proper performance of his duties when he commented on the appellants' character."

New book: Criminal Procedure in New Zealand

Those of you who need to pay attention to the criminal law of our small but picturesque country should be interested in a new textbook, shortly to be published by Brookers – Thomson Reuters:
Criminal Procedure in New Zealand

By Professor Jeremy Finn, Don Mathias, and Ron Mansfield.
It was written in anticipation of the commencement of the Criminal Procedure Act 2011 on 1 July 2013.

Getting good policy past the Fourth Amendment

Maryland v King
USSC No 12-207, 3 June 2013 illustrates how interpretations of the Constitution of the United States of America can distort perceptions of what is reasonable search. The Supreme Court split 5-4 over whether a statute was in breach of the Fourth Amendment's prohibition of unreasonable search insofar as it permitted the taking of a buccal swab from a person arrested for a serious offence, for DNA analysis and comparison with samples from the scenes of unsolved crimes.

The opinion of the Court was that this was reasonable and not a breach of the Fourth Amendment.

The dissenters, whose opinion was delivered by Scalia J, reasoned that the Fourth Amendment has always prohibited search without probable cause, and as the legislation in question permitted the search without even suspicion of the commission of an offence other than that for which the person had been arrested, it purported to authorise search without probable cause. The only relevant reason the challenged aspect of the statute allowed the taking of this sample was for comparison with DNA from unsolved crimes.

The majority held that a person who has been arrested may be searched, and that such a search is not based on probable cause but rather on reasonableness. Here the taking of the sample was reasonable because it involved minimal intrusion and the use of the DNA was a proper law enforcement interest. What the statute authorised here was not relevantly different from obtaining the fingerprints of an arrested person.

It is difficult to see how obtaining a buccal swab from an arrested person and using it for DNA analysis and comparison with DNA from unsolved crime scenes could be objectionable. There are competing interests: the arrested person's privacy, and society's need to promote law enforcement.

The privacy interest here could be analysed into two parts. First, the intrusion involved in providing the sample. This is relatively trivial and has little weight. Second – potentially far more important – the risk that a false positive match will be reported in circumstances where the analysis cannot be repeated because the sample from the crime scene is no longer available for further analysis, combined with the circumstance of the person not being able to rebut the false match with robust evidence of alibi. The coincidence of those two circumstances would be highly improbable, and this second part of the privacy interest should also be given little weight.

Society's interest in law enforcement reflects equality under the law. It is unfair that some offenders should go undetected while others have to face justice. In return for obeying the law we are entitled to insist that everyone else obeys the law. It is true that convictions of the innocent threaten equal justice, so the law must ensure they are kept to a minimum and when they occur redress is made. But overall it seems uncontroversial that society's interests outweigh the privacy interests of the arrested person in this situation.

Identification of the better policy is not difficult; the problem for the Court was to make that policy compatible with the Fourth Amendment.

The trend of legislation concerning the taking of body samples for DNA analysis is to diminish privacy rights. For example – and no doubt your own legislature has done this – in New Zealand the Criminal Investigations (Bodily Samples) Act 1995 has, over the years, been amended to increase the range of offences, arrest for which can trigger the taking of a sample. Amendments have also permitted the making of compulsion orders by officials of lesser rank than had originally been required. The general reduction of recognition of individual privacy rights has also occurred in relation to search and surveillance, with the threshold for most searches being reduced and there also being some reduction in the rank of the official who may authorise the activity. We are also authorising our security agency to gather intelligence (spy) on more people within our country than previously.

To clothe these thoughts in respectable garb, one reaches for a book and, seemingly by chance, comes upon Jacob Bronowski's The Ascent of Man (1973). In Chapter 13 he said this:

"It is a tightrope that man walks, between his desire to fulfil his wishes, and his acknowledgement of social responsibility. ... We devise ethical strategies or systems of values to ensure that what is attractive in the short term is weighed in the balance of the ultimate, long-term satisfactions."

It seems that society accepts that individual privacy must increasingly yield to the needs of law enforcement. That is the climate of our times, and reasonable people do not place their own privacy interests above more pressing societal concerns. There must, however, in the context of DNA sampling, be adequate safeguards against erroneous convictions.

There are concerns with legislation that follows this pattern. What if the person was arrested wrongly, or was subsequently acquitted, but his DNA was found to match a sample from an unsolved crime? An innocent person would then have been subjected to the risk of incrimination that should more properly be borne by the convicted. And, more generally, why is this sort of legislation directed at finding matches only with unsolved crimes; shouldn't it also be developed to serve as a check against wrongful convictions of other persons? Can't a DNA sample be used to exonerate as well as to incriminate?

Pragmatism and lawfulness

State of NSW v Kable [2013] HCA 26 (5 June 2013) is a reminder of the law's foundation in pragmatism. To make the legal system serve its purpose of providing orderly resolution of conflicts, it is necessary that the orders of a court be treated as effective unless and until they are overturned on appeal. There would be chaos otherwise [39]-[40].

So an order of a court for detention of Mr Kable was effective even though the legislation on which it was based was subsequently held unconstitutional. The order had not been set aside during the period of his detention, and his detention was pursuant to lawful authority of the order. He had not been unlawfully imprisoned. The officials who enforced the court order were right to do so.

Leaving that decision to one side for the moment, we can reflect on other instances where the law has to be pragmatic. A judge, or any other official who makes legally binding rulings, may appear to be doing so in a routine way, until someone points out that he was improperly appointed. He did not lawfully hold the office he appeared to hold. What then of all the decisions he had made?

But an official's appointment need not appear to be routine. A usurper may seize power, as in a military coup, sack the judges and "appoint" new ones. Life must go on. Ordinary legal problems must be resolved, ordinary laws need to remain enforceable. The uncontroversial orders of the obviously unlawfully appointed judges need to be obeyed, simply to avoid a worse breakdown of the social order.

One way to determine the de jure validity of the acts of de facto officials is to ask whether the person was in fact competent to exercise the jurisdiction in question, and whether the act of the official ought to be recognised. Are there circumstances of reputation and acquiescence, sufficient to colour the appointment and the acts with validity? See, for example In re Aldridge (1893) 15 NZLR 361 (CA) where a person had been appointed to a non-existent judicial office and his appointment had been held by the Privy Council to have been invalid: Buckley v Edwards [1892] AC 387. The authorities concerning officials who appeared to have been validly appointed, but weren't, are reviewed in State v Carroll 38 Conn. 449 (1871). As to officials who have obviously been unlawfully appointed, and where colour of right does not apply, see Honoré, "Allegiance and the Usurper" [1967] Cambridge LJ 214, and for the law's need to take into account revolutions or coups d'etat, Madzimbamuto v Lardner-Burke [1969] 1 AC 645 (PC). See also Jarrett, "De Facto Public Officers: The Validity of Their Acts and Their Rights to Compensation" 9 Southern California Law Review 189 (1936), and Brookfield, "The Courts, Kelsen, and the Rhodesian Revolution" (1969) 19 University of Toronto Law Journal 326.

Old stuff, discussion of which has no doubt been the foundation of many academic careers. I only mention it here because I am being nostalgic. Basically it is all about when and how the law should catch up with reality. The answer is not necessarily confined to whether the official was validly appointed or whether the law was valid.

So too in Kable, the question was more complex than mere validity of the law: [22]. The position, long established in Australia, is that "the orders of a federal court which is established as a superior court of record are valid until set aside, even if the orders are made in excess of jurisdiction (whether on constitutional grounds or for reasons of some statutory limitation on jurisdiction)" [32]. The effect given to the order that was made without jurisdiction comes from the status of the court, not from the invalid legislation, and the effect of the order continues until it is set aside on appeal [36]. Here, the order detaining Mr Kable had been set aside by the High Court in 1996, but that was after he had been released from custody.

This was an unsuccessful action for damages for false imprisonment. Mr Kable's position may be likened to that of a person who has served a sentence of imprisonment but whose conviction was subsequently quashed. The remedy, if there is one (and states make their own – pragmatic - arrangements to deal with these situations), is not an action for damages in tort for false imprisonment, for the imprisonment was lawful.

Giving reasons for dismissing appeals

The constitutional importance of reasons being given by an appellate court when it dismisses an appeal is emphasised in Laing v The Queen (Bermuda) [2013] UKPC 14 (14 May 2013):

"[14] ... All three members of the Board are well aware, from their own experience, of the pressures that are endemic to the criminal appeal courts. But the interests of justice must come first. Once again it must be stressed that an appellant has a constitutional right to be given the reasons for the court's decision if his appeal is dismissed. The more serious the offence of which he has been convicted and the more severe the sentence that has resulted from it, the more important it is that this right should be given effect. This should be done by giving written reasons for the decision or, where they have been given orally, for them to be recorded so that they can be transcribed into written form as soon as possible. Only then can one be certain that the constitutional right has been satisfied.

"[15] It will always be a matter at the court's discretion how much need be said, and whether it should deal with every point that has been raised in the course of the argument. But the guiding principle is one of fairness. The appellant is entitled to be assured that his case has been properly considered and to know why his appeal did not succeed ... ."

But here there was no reason to think that the conviction might be unsafe, and it could not be quashed simply because the appellate court had not provided its reasons for dismissing the appeal. A similar position had occurred in Maharaj v The State (Trinidad and Tobago) [2008] UKPC 28 (8 May 2008).

A failed attempt at retrospective criminalisation

Where an "offence is committed by an omission to perform an act that by law there is a duty to perform" (s 4.3(b) of the Criminal Code (Cth), in the form it was at the time relevant to Director of Public Prosecutions (Cth) v Keating [2013] HCA 20 (8 May 2013)), the duty must exist at the time of the commission of an alleged offence. So much is clear from the use of the present tense, as the High Court of Australia unanimously held in Keating at [49].

The offences alleged in Keating, essentially failure to inform the Social Security department of changes in circumstances that may have been relevant to entitlement to receipt of benefit payments, were against s 135.2(1) of the Code. The requirement there, of engaging in prohibited conduct, was that there must be a duty not to omit to disclose the relevant information. A duty of disclosure was introduced (as a result of DPP (Cth) v Poniatowska, noted here on 27 October 2011) by legislation having retrospective effect, but the existence of retrospective effect did not of itself mean that it engaged with the provisions creating the relevant offence: Keating at [47].

"[48] It is not to the point to observe that ignorance of the law affords no excuse or that the prosecution is not required to prove an intention to breach a legal duty. The submission ignores that the failure to do a thing is not an offence in the absence of a legal duty to do the thing [footnote 35: "Code, s 4.3(b)"]]. As explained in Poniatowska, s 4.3 of the Code is a reflection of an idea that is fundamental to criminal responsibility: that the criminal law should be certain and its reach ascertainable by those who are subject to it [footnote 36: "[Poniatowska] [2011] HCA 43; (2011) 244 CLR 408 at 424 [44] per French CJ, Gummow, Kiefel and Bell JJ; and see Glanville Williams, Criminal Law: The General Part, 2nd ed (1961) at 579-580; Ashworth, "Public Duties and Criminal Omissions: Some Unresolved Questions", [2011] Journal of Commonwealth Criminal Law 1"]. This idea underpins the strength of the presumption against retrospectivity in the interpretation of statutes that impose criminal liability. Mr Bennion explains the principle in this way [footnote 37; "Bennion on Statutory Interpretation, 5th ed (2008) at 807 (footnotes omitted)"]:

"A person cannot rely on ignorance of the law and is required to obey the law. It follows that he or she should be able to trust the law and that it should be predictable. A law that is altered retrospectively cannot be predicted. If the alteration is substantive it is therefore likely to be unjust. It is presumed that Parliament does not intend to act unjustly."

So in Keating the new legislation, aimed at overcoming the difficulty identified in Poniatowska, was inadequately drafted to overcome the presumption against unjust legislative intent. It did not render s 4.3(b) of the Code nugatory. It did not make a person criminally liable for past failure to perform what was not then an obligation.

Judicial redefinition of veracity evidence

In our Evidence Act 2006, the veracity rules concern particular kinds of character evidence. They may be used by a defendant to show a propensity to tell the truth, or by a prosecutor to show a propensity to tell lies. Either way, evidence of veracity is only admissible in limited, specified, circumstances.

Confronting a witness with a prior inconsistent statement is not of itself a challenge to the witness's veracity, because veracity refers to a general tendency, not to a particular instance.

Evidence that is admissible independently of the veracity rules is not therefore subject to the constraints of those rules. The veracity rules can permit the adducing of evidence that would not otherwise be admissible.

There are limits on the use of leading questions in examination and in re-examination of a witness. In re-examination a witness may be asked to clarify an ambiguity or an apparent contradiction in evidence given in cross-examination. The witness might also, in re-examination, be presented with a prior inconsistent statement – inconsistent with what the witness said in cross-examination - and asked to explain the inconsistency. This is not, of itself, necessarily cross-examination, although whether it is, and therefore whether it is only permissible if the witness is hostile, is a matter to be determined as an exercise of judgment in the particular case.

A defendant who uses a complainant's prior inconsistent statement is not using it as evidence of a lie, but rather as evidence of the truth (R v Davidson [2008] NZCA 410). But even if the prior inconsistent statement was being used as evidence of a lie, it would not for that reason alone be evidence of (lack of) veracity: it is particular, not evidence of a general disposition. The prior inconsistent statement is admissible as soon as the inconsistency emerges, and the veracity rules are irrelevant.

And obviously, a defendant is not shielded, by the limits on the use of evidence of veracity, from his own prior inconsistent statements (R v Tepu [2008] NZCA 460, [2009] 3 NZLR 216). The veracity rules are again irrelevant, the prior inconsistent statements being particular in nature, not evidence of a general propensity to lie.

These points are made in Hannigan v R [2013] NZSC 41 (26 April 2013). They certainly seem obvious, although the Court split 4-1. The Chief Justice dissented on the grounds that the rule prohibiting cross-examination by a party of its own witness (s 94) should have been applied. This conclusion follows from a different judicial assessment of the quality of the questioning than was made by the majority.

The case was decided on that difference, but the obiter nature of the judicial observations on the veracity rules should not detract from their authoritative status. They give guidance that is obviously of assistance, and (I sarcastically add) at the current rate at which the Court refuses leave to appeal – because counsel don't identify appropriate grounds – we would otherwise have to wait hundreds of years for another opportunity for the Court to clarify the veracity rules.

Anyway, before Hannigan the law on the admissibility of evidence of veracity was uncertain, and the appellant's case was indeed arguable. The dissent illustrates this.

Elias CJ considered the relationship between s 37(4) and s 94. She held that in this case the questions in re-examination were leading and cross-examination [33], [36], and that therefore hostility had to be established. She accordingly disagreed with the majority on the nature of the questions in this case [40]-[41]. She also held that a finding of hostility is always required before a party can cross-examine its own witness, irrespective of whether a prior statement is independently admissible [43]. Significantly, Elias CJ pointed out [46] that the majority approach to the definition of veracity evidence in s 37(5) ignored the particular aspect of the definition: a disposition to refrain from lying, whether generally or "in the proceeding". She took a wide view of when a witness might be held to be hostile [52], and concluded that in this case the judge could, after proper inquiry, have concluded that the witness was hostile [57].

Recently I heard someone say that dissenting judgments tend to become the law in a few decades. No they don't. Dissents very rarely become the law, and it is only because of this rarity that they are noticed when they do, and their tendency to become law is exaggerated. It is not unusual for judges to disagree about the law and about its application to the circumstances of the case they have to decide.

But the effect of Hannigan is to iron out a crinkle in the definition of veracity evidence that occurs in s 37(5). The definition as enacted is too broad insofar as it includes a disposition to lie "in the proceeding". The majority have interpreted s 37(5) by ignoring that inclusion, and have thereby restored the original intention behind the legislation: to restrict evidence of collateral issues. As the majority note at [137], the Law Commission in "The 2013 Review of the Evidence Act 2006" NZLC R 127 (February 2013) has recommended a change to the definition of veracity evidence along similar lines (see 6.56 – 6.69 of the Report). The majority in Hannigan has in effect changed the definition in response to the difficulties that the Law Commission has summarised. [Update: Section 37(5) has been amended from 8 January 2017 by deletion of the reference to "in the proceeding".]

While looking at the Law Commission's report I should say something about its treatment of concerns that have been expressed about s 30 of the Evidence Act 2006. I agree with the Commission's recommendation that the section, which addresses when improperly obtained evidence may be excluded, does not need changing except in a minor way that the courts have anticipated. Decisions under s 30 have troubled academic commentators, who focus on the very few cases that are apparently wrong, rather than on how the section works satisfactorily in the overwhelming majority of cases. I often encounter younger colleagues who, just out of law school, regard s 30 as a "whatever-the-judge-wants-to-do" sort of provision. I hope that attitude does not reflect a failure of teaching. It is much more interesting to work out how judicial decisions under s 30 may be predicted, than to offer unconstructive and uninstructive criticisms.

Search and the implied licence to enter private property

In criminal law the facts can be simple but the law complex. This is why criminal lawyers appear to some observers to be vastly more intelligent than their colleagues who practise in civil law.

The implied licence to enter private property can give rise to differences of judicial opinion on whether a police officer carried out a search and if so whether it was done lawfully.

In Florida v Jardines, USSC No 11-564 the Court split 5-4 on the lawfulness of a search where an officer had taken a drug dog on a lead to the front door of a house intending to knock and speak to the occupier. The officer was acting on information that drug offending was occurring on the property. The dog indicated the smell of drugs and the officer left the property with the dog and obtained a warrant to search the address. When the warrant was executed evidence of cannabis offending was found.

The opinion of the Court, delivered by Scalia J, was that the officer with the dog had carried out a search in breach of the implied licence to enter and knock. The main grounds for this decision were trespass, but in a concurring opinion Kagan J, joined by Ginsburg and Sotomayor JJ, the alternative ground of breach of privacy was advanced as an easier answer. The dissent was delivered by Alito J, joined by Roberts CJ, Kennedy and Breyer JJ.

The facts invite consideration of a variety of issues:

• What was the significance of the presence of the dog?
  
• Do the police have common law powers that ordinary members of the public do not?
  
• Should lawfulness here be determined by considerations of trespass or of privacy?
  

Alito J denied that the implied licence that qualifies trespass had ever been held to have prevented an officer bringing a dog onto the property. Obviously that point is not particularly significant because the law hasn't yet anticipated every possible occurrence. Absence of authority for a proposition is not authority against the proposition, although it can suggest that the conduct has previously been thought reasonable.

Alito J pointed out that the law has never attempted to distinguish categories of visitors as being welcome and therefore within the implied licence or unwelcome and therefore outside the licence. Any visitor with a lawful purpose may enter at a reasonable time of day and walk on the path that typically approaches the front door and, without lingering, knock on the door in an attempt to speak to an occupant. The police may do this too, and they do not search by simply approaching the door to knock and talk, even where the intention is to talk with a view to obtaining evidence against an occupier.

And if, continued Alito J, the officer in approaching the door with that intention, happened to smell evidence of drug offending, that information is not obtained outside the scope of the implied licence. So too for things seen and heard from a lawful vantage point. The officer is permitted to smell, hear and see what any person might detect on a lawful approach to the front door (citing State v Cada, 129 Idaho 224, at 232, 923 P. 2d 469 at 477).

Given that the officer could use his own nose, continued Alito J, what was wrong with him using the dog? There was no authority prohibiting the officer from having the dog with him, and indeed there has been no case in 800 years in which a tracking dog has been held to create a trespass. So, concluded the dissent, trespass is not a proper basis for holding the present conduct unlawful.

Nor, continued Alito J, could the occupiers have any reasonable expectation of privacy in relation to odours emanating from unlawful activities and reaching places where members of the public may lawfully stand. This is not the same as the use of new technology to enhance the sensing of information. It would hamper legitimate law enforcement activity if the dog's nose were to be equated with new technology.

However the dissent must now be regarded as incorrect in the jurisdictions in which Jardines applies. This is not to say that elsewhere the dissent's view of the law should not be accepted. Although the Court was concerned with constitutional interpretation, the origins of the law against unreasonable search and seizure are in the common law of England. While originating in the customs of England, the common law can develop differently according to social needs in different places. And a change in the common law brought about by decisions of the European Court of Human Rights in relation to judicial decisions made in Britain (for example as occurred in Malone v United Kingdom [1984] ECHR 10, overturning Malone v Metropolitan Police Commissioner [1979] Ch 344) does not necessarily affect the common law of another country. So although Jardines is not a "common law" decision in the narrow sense that the term "common law" is used in the United States, it is of interest wherever the meaning of search and the scope of police powers in relation to private property have to be decided.

The opinion of the Court in Jardines therefore is not binding but is "of interest" to courts outside the jurisdiction in which it applies. Scalia J, after deciding that the investigation took place in a constitutionally protected area, turned to consider whether the intrusion was authorised. Inevitably the relevant common law decision, known to the Founders and repeating an ancient custom of the realm, is Entick v Carrington, 2 Wils. K.B. 275, 95 ER 807 (K.B. 1765). As every lawyer knows, or once knew, this case reminds us that "our law holds the property of every man so sacred, that no man can set his foot upon his neighbour's close without his leave."

This rule, underlying the Fourth Amendment, raised the question whether a licence to enter could be implied in the circumstances of this case. Scalia J held that introducing a trained police dog to explore the area around the home was not customarily recognised as being within an implied licence to enter. The scope of the licence to enter and knock on the front door was limited both to a particular area and to a particular purpose. There was no invitation to the officer to enter and conduct a search. It was not the dog that was the problem, so much as the purpose of the entry. The common law would not licence a person who, remaining on the path to the door, used binoculars to peer through a window.

The Fourth Amendment has a property-based interpretation, supplemented in appropriate cases with a privacy based interpretation. Where a case can be decided on property-based grounds there is no need to add an inquiry about whether the defendant had a reasonable expectation of privacy. Here, reasoned Scalia J, the use of the dog and questions about privacy interests in respect of odours emanating from illegal activities on the property, were privacy issues and did not need to be considered because the case turned on property interests. The point was that the officer entered to conduct a search and that was outside the implied licence. Since there had been an unauthorised search, the Court upheld the Supreme Court of Florida's decision that the trial judge had correctly excluded the evidence obtained through entry with the dog and execution of the improperly obtained search warrant.

It is not inevitable that issues concerning searches have to be analysed in terms of first property rights, then if necessary, privacy rights. The reverse can also work, as is illustrated by the concurring opinion in Jardines, and, for an example from further afield, in Hamed v R [2011] NZSC 101, at [163]. Hamed also contains some controversial remarks from the Chief Justice about whether the police have common law powers that ordinary people do not have (she held that they don't), and although the other members of the Court did not directly address that point the Court of Appeal has subsequently decided – although in my view by a bit of a stretch - that Hamed is consistent with the view that the police do have additional common law powers: Lorigan v R [2012] NZCA 264. The consequences of illegality may also differ between jurisdictions, and may be determined by legislation. The interpretation in Hamed of the relevant statute was discussed here on 19 September 2011. Some attempt has been made in New Zealand to codify the law of search: Search and Surveillance Act 2012. In circumstances like those in Jardines the relevant section would be s 20, but this does not specify the bounds of an implied licence. The consequences of a breach of an implied licence are left to be determined in the same way as before the Act (which is due to come fully into force by 1 April 2014, if not earlier by Order in Council). The position is summarised in Adams on Criminal Law – Rights and Powers, para SS20.05:

Where the constable's reasonable suspicion as to the commission of an offence has been derived from the unlawful actions of the police, the exercise of the warrantless search power may be unreasonable in terms of s 21 of the New Zealand Bill of Rights Act 1990: see, for example, R v Hjelmstrom (2003) 20 CRNZ 208 (CA) (consent to presence on property obtained through misleading the occupant). See also Lord v Police (1998) 5 HRNZ 92 (HC). However, even where the police presence at a place is without lawful authority, drugs seized in the course of the exercise of the search power on reasonable grounds may be admissible under s 30 of the Evidence Act 2006: see, for example, Eruera v R [2012] NZCA 288 (cannabis seizure in course of executing invalid search warrant for stolen property). For an example of evidential material discovered in the course of an unlawful search being held to be inadmissible, see R v Yeh [2007] NZCA 580.

This new legislation gives no guidance to the police about what they may do when they enter private property subject to an implied licence.

Your own jurisdiction may well have the same uncertainties as mine. To what extent do common law powers exist in the context of legislation? Do the police have greater common law powers than ordinary members of the public regarding entry onto private property? What are the terms of any implied licence to enter that apply to police officers? Does the characterisation of an entry as a search depend on privacy or on property rights? What sort of detection devices may be used in relation to private property pursuant to the common law?

People unfamiliar with the law's delays might be surprised that these questions can remain after 800 years. Good legal advice would be to set aside a further 800 years for the answers to emerge.

Informed advice on consequences of plea: changing perceptions of fairness

Sometimes when judges make new rules they apply retrospectively to cases that have already been decided. Obviously this could cause chaos, so there are limitations that confine the situations in which this retrospectivity can apply. In the United States, as we saw here on 21 February 2008, the rule in Teague v Lane, 489 U.S. 228 (1989) recognises two exceptions to the general rule that decisions do not apply retrospectively: where laws proscribing conduct have been declared unconstitutional, and where new rules concern the fairness of trials. Teague has been applied recently in Chaidez v United States
USSC No 11-820, 20 February 2013.

In Chaidez the appellant sought application to her case of a rule that had been declared by the Supreme Court after the proceedings in her trial had been finalised. The rule is that counsel must advise a non-citizen client of the immigration status implications of a plea of guilty: Padilla v Kentucky, 559 U.S. 356 (2010). Ms Chaidez had not been advised that her permanent residency would be revoked and that she faced mandatory removal as a result of her guilty pleas and convictions for mail fraud charges that were classified as aggravated felonies.

The Court held that the Padilla rule did not apply retrospectively.

This rather surprising result arose from what the majority regarded as the first issue which was whether advice about deportation came within the Sixth Amendment right to counsel. Does the right to counsel include the right to advice about a collateral matter – the consequences of a conviction on immigration status? Before Padilla the states had almost unanimously held that it does not. Padilla created a new rule for most jurisdictions. This new rule did not apply to Ms Chaidez's case because (the opinion of the Court is not clear on this but one can infer the reason) it did not, in terms of Teague, concern the fairness of the criminal proceedings against her.

Sotomayor J, joined by Ginsburg J, dissented. They reasoned that Padilla did not create a new rule but it merely applied the established rule that legal representation must be to a standard consistent with prevailing professional norms (Strickland v Washington, 466 U.S. 668 (1984)). Those norms had developed to require advice about the immigration implications of a guilty plea. Padilla did not apply a direct-or-collateral consequence approach to the Sixth Amendment, and Ms Chaidez's legal representation had fallen short of the required standard.

Outside the United States a retrospectivity issue of the kind that arose in Chaidez would probably be resolved by asking whether the defendant should have been advised of the consequences of conviction, including deportation. The rules of professional conduct should indicate the extent of a lawyer's obligation to advise a client of the consequences of a decision. For example, the Lawyers and Conveyancers Act (Lawyers: Conduct and Client Care) Rules 2008 [NZ], rule 13.13.1:

"When taking instructions from a client, including instructions on a plea and whether or not to give evidence, a defence lawyer must ensure that his or her client is fully informed on all relevant implications of his or her decision and the defence lawyer must then act in accordance with the client's instructions."

A retrospectivity issue would arise if standards had changed so that although advice on immigration status might not reasonably have been required to have been given at the time the client entered a guilty plea, it would be required now. This is an artificial issue here, as it has long been recognised that such advice must be given. But if there had been a change in this, so that "all relevant implications" now include the effect of a conviction on immigration status, would all defendants who had previously entered guilty pleas without that advice now be able to have their convictions quashed and their pleas re-taken?

While it is true that standards of fairness change over time, defendants who are still around to complain of treatment that by current standards was unfair are likely to have a remedy. See Krishna v The State (Trinidad and Tobago) [2011] UKPC 18, discussed here on 12 July 2011.

Jeopardy from silly acquittals?

"To permit a second trial after an acquittal, however mistaken the acquittal may have been, would present an unacceptably high risk that the Government, with its vastly superior resources, might wear down the defendant so that 'even though innocent he may be found guilty"

This from Green v United States, 355 U.S. 184, 188 (1957) was quoted in Evans v Michigan
USSC No 11-1327, 20 February 2013. Here an acquittal had been directed at trial although on grounds that were plainly wrong. The acquittal was nevertheless valid and effective to invoke the rule against double jeopardy.

Evans highlights the distinction between procedural terminations of trials and findings on the merits. A procedural termination is not an acquittal because it is not a finding on the merits. A procedural termination avoids the defendant being in jeopardy of a conviction. A properly granted mistrial does not give rise to an expectation of finality.

In Evans the judge ruled at the close of the prosecution case that the evidence so far adduced was insufficient to convict the defendant. The judge wrongly thought that the relevant law of arson required proof that a particular building was not a dwelling, and directed a verdict of not guilty accordingly. This was held to have been a ruling on the merits and a bar to a retrial.

You can see that this is a bit silly. We saw an analogous sort of silliness in R v Taylor [2008] NZCA 558, discussed here on 18 December 2008. Taylor was applied in Connolly v R [2010] NZCA 129 at [65]-[66].

It is silly because it turns on the stage of a trial at which an objection is taken: has jeopardy of conviction arisen? If the prosecution case has been closed, then yes, there is jeopardy, as in Evans. But what if, after the jury had been selected and the trial begun, the defence had objected that on the basis of the evidence that the prosecutor intended to call there was no proof of an element of the offence, and before any evidence was called the judge ruled that the prosecutor needed that evidence, and the prosecutor confirmed it would not be adduced, and the judge then directed an acquittal? Would jeopardy have arisen? Is this a procedural termination? The position as it would inevitably be if the prosecution case proceeded to closure is being anticipated. Why wait until closure of the case? Yet the authorities suggest that this would be a procedural termination, not a decision on the merits.

Is there a sensible policy behind treating directions that are obviously wrong in law as nevertheless giving rise to legally effective acquittals? If there is, is it consistent with whatever policy might justify distinguishing between procedural dismissals and rulings on the merits?

Sniffer dog reliability and probable cause for search

There were times when Aldo the drug dog was not on his best form. He was trained to detect the presence of particular drugs, but sometimes he would say one or more of them was there when that was wrong, although on the occasion that concerned the United States Supreme Court there were other drugs present: Florida v Harris, USSC No 11-817, 19 February 2013.

What was the relevance of a record of false positives to the existence of probable cause for a search based on Aldo's indication?

Probable cause requires the kind of "fair probability" on which "reasonable and prudent [people,] not legal technicians, act": Illinois v Gates, 462 U.S. 213. The totality of the circumstances must be looked at, and rigid rules, bright line tests and mechanistic enquiries are inappropriate, according to Gates.

The Court, in a unanimous opinion delivered by Kagan J, considered that field-performance records may not capture a dog's false negatives or may markedly overstate a dog's false positives. This is because in the field – that is, in real-world performance – a dog's failure to detect drugs will often not be followed by a search and so the failure will go unrecorded. Similarly, an apparent false positive may in reality be a correct response to a residual odour or a small amount of drug that the officer failed to find. But evidence of the dog's reliability in a controlled setting, where errors are known, can provide sufficient reason to trust the dog's alert in the field.

All the evidence needs to be evaluated, said the Court. Here the facts supported a finding of probable cause because the defence had not contested the State's evidence that Aldo performed reliably in controlled settings. But where the defence did challenge the evidence of the dog's reliability the court should assess all the evidence and ask whether all the facts, viewed through the lens of common sense, would make a reasonably prudent person think evidence of offending would be found. "A sniff is up to snuff when it meets that test." Haw haw.

Here the problem with the Florida Supreme Court's approach was that:

"No matter how much other proof the State offers of the dog's reliability, the absent field performance records will preclude a finding of probable cause. That is the antithesis of a totality-of-the-circumstances analysis."

There may be other indicia of reliability, and absence of one sort may be compensated for by presence of another.

Because the defendant had not raised issues of Aldo's reliability at trial, he could not do so for the first time on this appeal.

"As the case came to the trial court, Aldo had successfully completed two recent drug-detection courses and maintained his proficiency through weekly training exercises. Viewed alone, that training record—with or without the prior certification—sufficed to establish Aldo's reliability."

Good doggie.

Secondary participation in conspiracy

For a compellingly logical analysis of secondary participation in conspiracy, see R v JF, 2013 SCC 12 (1 March 2013).

Although the form of secondary liability considered in JF is aiding or abetting under s 21 of the Criminal Code, the same reasoning would apply to the other forms of participation that are usually included as constituting secondary participation: inciting, counselling or procuring.

The focus is on the actus reus of conspiracy, which is an agreement to commit an offence. The actus reus for secondary liability is aiding, abetting, inciting, counselling or procuring the formation of the agreement. Because the agreement may continue up to the attainment of its unlawful object, a person may join the agreement after its initial formation. A person who aids, abets, counsels or procures that person to join at that later stage commits the actus reus of secondary participation in the conspiracy.

A person who aids (etc) a conspirator in the attaining of the object of the conspiracy is not for that fact alone a conspirator, because the attaining of the object of the conspiracy is not the actus reus of conspiracy. But that evidence will usually support an inference of assistance in the entering into of the agreement by the person who is aided (etc), and if that inference is permissible in the circumstances then it is evidence of the actus reus of the aider's (etc) secondary participation.

This decision removes doubts that had existed in Canada over whether liability could arise from the mere assistance of a conspirator in the furtherance of the conspiracy. The approach in R v McNamara (No 1) (1981) 56 CCC(2d) 193 (Ontario CA) was not followed.

Old problems with new evidence

Whether failure to call evidence at trial should be grounds for quashing a conviction is an issue that often has to be decided in appeals, as it was in Taylor v The Queen (Jamaica) [2013] UKPC 8 (14 March 2013).

Here the Board split, Lord Kerr dissenting, on the application of the law to the facts. There was no difference of opinion on what the law is.

It was unnecessary to decide whether counsel were at fault in not calling the relevant witness, because the issue is the impact of the absence of the evidence on the verdict: Lord Hope for the majority at [13], applying Lord Carswell in Teeluck v State of Trinidad and Tobago [2005] UKPC 14 at [39], (discussed here on 1 April 2005). The test is whether, after taking all the circumstances of the trial into account, there is a real possibility of a different outcome: Taylor at [20]. Might the evidence reasonably have affected the jury's decision to convict? The majority held that there was no reasonable possibility in this case that the jury would have arrived at a different verdict.

Lord Kerr said that the requirement of a real possibility of a different verdict signifies no more than an acceptance that one is left in doubt as to the safety of the conviction [39]. This, he added (more obscurely), was not a matter for one side or the other to take on the burden of showing, but instead is a matter that must be decided in the round. The question of the effect of the new evidence on the safety of the verdict is for the appellate court to decide for itself; the court does not decide what effect the evidence might have had on the jury: [43], applying Dial v State of Trinidad and Tobago [2005] UKPC 4 (noted here on 17 February 2005). Further, the question is not whether there was evidence on which the jury might reasonably convict, but rather whether there was evidence on which it might reasonably decline to do so: [45], applying Bain v The Queen (New Zealand) [2007] UKPC 33 (discussed here on 11 May 2007).

Therefore it is in this sense, said Lord Kerr, that the question, where new evidence has come to light, is whether the evidence might reasonably have led to an acquittal [46]. He proceeded to analyse the case and reached a different conclusion to that of the majority.

The application of this law is notoriously difficult for appellate courts, and it is not unusual to find dissenting judgments. One also finds dissents in appeals which have to consider, not the failure to call evidence at trial, but the wrongful adducing of evidence at trial. A spectacular example is Howse v R [2005] UKPC 31, discussed here on 23 July 2005. The wrongful adducing of evidence raises the substantive question of the fairness of the trial, and the inevitability of a guilty verdict is not the touchstone, for even a guilty defendant is entitled to a fair trial.

Trial fairness is also raised by a failure to adduce evidence and we might wonder whether the criterion for quashing a conviction in such a case should be whether the absence of the evidence might have undermined the fact-finder's impartiality: could inappropriate weight have been given to critical prosecution evidence because of the absence of the evidence?

Attribution and the actus reus

Sometimes where there is more than one defendant alleged to be a principal offender (that is, one who personally does the actus reus with the required mens rea) it is difficult to say who did what. This is particularly so where there are a lot of eye witnesses, for it is normal to find that everyone has a different account of what happened. There may be no doubt that an actus reus occurred, but who did what?

This was considered in Huynh v The Queen [2013] HCA 6 (13 March 2013). "Joint enterprise" liability of this kind (which is not to be confused with the term joint enterprise in the context of an exception to the rule against hearsay, nor with similar terminology that is sometimes used in relation to extended secondary liability) depends on proof that the defendant was a party to an agreement to commit the offence that was committed and in addition - for this is not mere conspiracy - that the defendant participated in the offending. Presence when the offending occurred can be sufficient to prove participation. The circumstances may also, as they were in this case, be such that the defendant's presence supports an inference that it was pursuant to the required agreement.

This common law solution to the determination of liability as a principal offender where the facts are vague has a parallel in the interpretation of the statutory criterion, for liability as a principal, of being a person "who actually commits the offence": see for example s 66(1)(a) of the Crimes Act 1961 [NZ]. There is an appeal case, the name and details of which seem still to be subject to a suppression of publication order, so I give only the citation for people with access to databases on which publication is permitted: "[2010] NZCA 256". In that case there were several steps needed to complete the actus reus and several defendants were allegedly involved, but no one person did all the steps. In relation to any given defendant, the prosecutor had to prove that that defendant did any of the required steps, that one or more other of the defendants did the other necessary steps, and that the defendant under consideration had mens rea. This was called a distributive application of s 66(1)(a).

Is the distributive approach the same as the joint enterprise liability illustrated by Huynh? Probably yes, although particular facts may produce different results. That would depend on what inference could be drawn from a defendant's presence when another defendant completed a step in the actus reus. The common element is participation in the offending in circumstances where the acts of one defendant are attributed to another.

When will this attribution occur? Policy considerations strongly favour public safety, but there should be clear limits on attribution. For a controversial approach see R v Gnango [2011] UKSC 59, [2012] 1 AC 827, discussed here on 18 December 2011, where the majority favoured liability as a principal for murder where the defendant was in a gunfight with the person who, missing him, shot a bystander.

Guidance was given to judges in both Huynh and "[2010] NZCA 256" on how to handle complex cases, where there are multiple defendants and different forms of alleged liability. Huynh stresses the importance of getting to the real issue in the case, so that the judge can give a focused direction on the law. The New Zealand case at [26] invites judges, when faced with disagreement from counsel on the structure and content of a proposed question trail for the jury, to make a minute recording the nature of the dispute and the judge's reasons for adopting the trail ultimately used.