Deterrence or rights protection: why exclude improperly obtained evidence?

Davis v United States (2011) USSC No 09-11328, 16 June 2011 emphasises the rationale for declining to exclude evidence obtained by unreasonable search that had been established in Herring v United States (discussed here 15 January 2009). This is that evidence should be excluded if doing so would have a deterrent effect against police misconduct. At the time of the search in Davis, the search was lawful, but afterwards the law was changed by Arizona v Gant (noted here 22 April 2009). That meant that there was, at the time of the search in Davis, nothing to deter, and the evidence was admissible notwithstanding the later change in the law.

What this sort of deterrence aims at is police conduct that is in flagrant, deliberate or reckless disregard for the Fourth Amendment rights. Where the police act in good faith, or where they are merely negligent, and they violate the defendant's rights, deterrence is not called for and exclusion of the evidence would not "pay its way".

A more rights-centred approach to exclusion of improperly obtained evidence pertains elsewhere, but you knew that.

Public Defence Service costs and private bar legal aid costs

A spat looms on whether the Public Defence Service is more expensive than having legally aided criminal cases dealt with by the private bar:

Wellington, June 24 NZPA - The Government wants to save money by expanding the Public Defence Service (PDS) but Labour says the United Kingdom experience shows it is more costly.

The Government intends to increase the PDS' share of the criminal caseload from 33 percent to 50 percent.

Criminal lawyers have argued the PDS was incapable of delivering a competent and independent service, lawyers would be less experienced, clients would be pressured into pleading guilty and that it would be more costly.

Justice Minister Simon Power and the PDS disagree, saying it was working well.

Labour MP Charles Chauvel said today that the latest review of the PDS in England and Wales showed costs between 41 percent and 58 percent higher than independent lawyers providing the same services.

It also raised concerns about how PDS costs were calculated.

Mr Chauvel called for Mr Power to release full costs of the PDS.

"The Justice Minister hopes to cut legal aid costs by significantly expanding the Public Defence Service (PDS) — a public service entity — at the expense of independent lawyers providing legal aid," Mr Chauvel said.

"Labour created the PDS and continues to support its existence. But we never intended to expand it as Simon Power wants to. It was always our view, and it remains our view, that independent lawyers should provide the bulk of criminal defence work, for efficiency and equity reasons."

Mr Power said the UK report was published in 2007 and Mr Chauvel was not comparing apples with apples.

"The criminal legal market in the UK is quite different to that in New Zealand," Mr Power said.

"In the UK there is already an extensive network of private firms providing criminal services, making it difficult for their PDS to build market share.

"In New Zealand rotational case assignment will see the PDS receive cases on a regular basis."

Mr Power said expanding the PDS was not just about addressing the cost of legal aid funding.

"It was also recommended by Dame Margaret Bazley in 2009 to improve the quality of legal aid services," he said.

I emphasise the "apples with apples" bit because it raises an interesting point about how to compare the costs of the PDS with those of the private bar.

The idea used by Mr Chauvel in this media report seems to be that the relevant costs will decrease as more work is done. This supposes that the relevant calculation is costs per case.

I think that the better calculation is costs per funded hour in court by counsel appearing in a case. So, for a year, take the total costs that are publically funded for the practice, and divide it by the total publically funded hours spent by counsel from that office in court. For the private bar, average those costs per hour to get costs per hour per firm, and then compare that average to the costs per hour for the PDS office.

This way of looking at it asks how much does it cost to put a PDS lawyer in court compared to putting a publicly-funded private lawyer in court. The "apples" are court-hours. This is a neutral basis for comparison. If the "apples" were cases the comparison would be complicated by the various kinds of cases and whether the best legally available outcome for the client was achieved in each.

Bring on the holidays!

Grown-ups will remember when we used to use the pejorative term Kafkaesque. This word comes to mind on reading R v EMW 2011 SCC 31 (17 June 2011). To call the opinions "reasons for judgment" is an exaggeration. They read more like an inadequate headnote. Perhaps the unsuccessful appellant will be wondering if the judges really earned their pay on this one. It is impossible to evaluate the strength of Fish J's dissent. And while we must accept the majority's conclusions there seems to be no discernable lesson to the Court of Appeal, whose majority decision was overruled. Just a difference of opinions. I think a court of final appeal has a duty to explain itself more clearly.

The majority disagreed with the  Nova Scotia Court of Appeal majority (and apparently too with the dissenting judge in that court who seems to have accepted this point) as to whether Crown questioning of the complainant had been leading. The questioning is set out at para 80 of the NSCA majority judgment and more extensively at [118] of the dissenting judgment of Fichaud JA. At trial, after a stick drawing of a female person had been drawn by the prosecutor and the complainant had drawn a circle in the general vicinity of where the defendant had been touching her inappropriately, the questioning continued (I insert numbers for the questions):
"1. Q. Yes. What’s that part of the body on a female called?
A. Vagina.
2. Q. Vagina. And was your dad touching you on the vagina? 
A. Yes.
3. Q. And when he touched you on the vagina, was it outside of your vagina or inside of your vagina?
A. Inside.
4. Q. What part of his body was he using to touch the inside of your vagina?
 A. His fingers.
 5. Q. Was he on the inside or the outside of your clothes when he was doing this?
A. Inside.
6. Q. So you would wake up and your dad’s hand would be down your pants, and his fingers would be in your vagina?
A. Yes."

The Supreme Court majority held [9] that this was not leading questioning. But did it suggest answers or assume a state of facts that was in dispute? Q2 leads; it should be "Where was your dad touching you?" Q3 should be "Which part of your vagina was he touching?" Q5 should be "Were you wearing anything?" then, "Where was his hand compared to your clothing?" Q6 should be "When did you notice that?"

An interesting point concerns Fichaud JA's treatment of the defence cross-examination on these matters. Fichaud JA regarded the defence tactic of getting the complainant to repeat this evidence (by questions which in cross-examination are not, of course, objectionable for being leading) as defeating any objection that could have been made at trial to the Crown's leading of the same evidence. I should say that the defence cross-examination technique was flawed: it was wrong to get the complainant to repeat her evidence in chief; counsel should merely have led the inconsistent statement and then put the proposition that both were lies. But, given that counsel chose to repeat what in the hands of a prosecutor was objectionable, did this create a sort of estoppel on appeal against objection to the prosecutor's leading? I think not, because if the questions had not been allowed in chief they would not have been repeated in cross-examination.

The Supreme Court did not address this. Nor did it explain why the questions were not leading, except to say that binary questions (giving the complainant a choice between two alternatives, as in Q3 and Q5 above) did not here suggest an answer. Well, in the context of this case those questions were peripheral: the point was the allegation that the defendant was touching her vagina. Inside or outside vagina, or inside or outside of clothing, was of secondary importance. But in any event, binary questions are not necessarily acceptable, as they serve to reinforce the preceding answer, here that the vagina was touched, and that clothing was worn.

Oddly McLaughlin CJ for the majority said, on the issue of whether the questions suggested answers or assumed facts that were in dispute, that they "did not cross this threshold". There is a threshold? They were sort of leading but not quite? Is there a category of questions that are acceptably leading in a context where leading is prohibited? The majority did not say, yes, these were leading questions, but in this case the complainant was young and the prosecutor was having difficulty getting her evidence, so the judge was right to allow these questions. If that was what the majority intended, it would be controversial. Compare the remarks of the New Zealand Court of Appeal in R v E (CA308/06) [2007] NZCA 404, [2008] 3 NZLR 145 at [25]:
" We are conscious that there are some cases and commentators which suggest that leading questions may be allowable where young children are concerned . . . Given what is now known about the importance of using open-ended questions when interviewing children, these authorities should be treated with caution. We note, in any event, that under s 89 of the Evidence Act 2006, there is no exception to the prohibition of leading questions where a child is being questioned."

Risks, aversions, coercion, and provocation

A clutch of recent Privy Council decisions: the risks of dock identification, the Board's aversion to the death penalty, jury perception of coerced confessions, and puzzling over provocation.

R v Tido (Bahamas) [2011] UKPC 16 (15 June 2011) has some useful dicta on dock identification, application of the proviso where inadmissible evidence had been before the jury, and on the discretion to impose the death penalty in the worst cases of murder.

In Miguel v The State (Trinidad and Tobago) [2011] UKPC 14 (15 June 2011) there is an interesting point reiterated about the Mushtaq direction ([2005] UKHL 25, discussed here on 22 April 2005 and also, in the context of Wizzard [2007] UKPC 21 here on 6 April 2007). This is that there is a distinction between on the one hand denial that a statement was made at all, as where the defendant says the police coerced him to sign a confession they concocted, in which case the Mushtaq direction does not apply, and on the other hand acknowledgement that the confession was his but that it was coerced. In the latter case, where the question concerns the voluntariness of an acknowledged confession, Mushtaq does apply so that the jury must be directed to ignore it if they think it may have been obtained by coercion. This was the explanation of Mushtaq that had been given in Wizzard.

Although Mushtaq is discussed as if voluntariness were an issue on which the jury had to be unanimous, it seems obvious that unanimity is not required because each juror may find his own route to a decision on guilt, and it is only on the verdict that the members must be unanimous. So if a juror relies on the confession, that juror must be satisfied (beyond reasonable doubt - the standard applying to voluntariness here) that it was made voluntarily.

In Miguel the Board, once again, found a way to avoid upholding the death penalty. This time the reasoning focused on the interpretation of constitutional legislation.

The third decision of the Privy Council addresses provocation and fresh evidence that could be relevant to that defence: Lewis v The State (Trinidad and Tobago) [2011] UKPC 15 (15 June 2011). Provocation has been replaced in England and Wales by the partial defence of loss of control: ss 54-56 of the Coroners and Justice Act 2009[UK], and Lord Brown for the Board commented [28]:

"...whatever difficulties may arise in England and Wales from the introduction last October of the new defence of loss of control in place of provocation, at least there will be fewer problems of the kind discussed above. The courts in Trinidad and Tobago however, must soldier on. It will now be for the Court of Appeal there to consider the question of provocation in the present case. We have no alternative but to remit the matter to them."

In Lewis the problems concerned identifying conduct by the victim that could qualify as provoking the defendant to lose self-control. Mere causing loss of self-control is insufficient, because then provocation would need to be considered whenever self-defence was raised (R v van Dongen (Anthony Gerrard) [2005] EWCA Crim 1728; [2005] 2 Cr App R 632 at para 42, quoted in Lewis at [16]). In Lewis the judge had decided not to leave provocation to the jury, and the Board upheld that (although because of fresh evidence the case was remitted to the Court of Appeal). This reflects a view that what is sufficient evidence of provocation is not a question of law but is best left to the common sense of the trial judge [13, 21]. It is necessary to distinguish killing as revenge from killing as a result of loss of self-control, but the Board felt it unhelpful to try to separate out the evidence of provocation from evidence of loss of self-control [15]; they are closely connected aspects of the first limb of provocation (the subjective requirement that the defendant was provoked into losing his self-control). This first limb is regarded as "a single composite" [16], and the judge will refuse to leave provocation to the jury if he concludes that it would be perverse for a jury to find that a reasonable person would do what the defendant did.

An illustration of a controversial reliance on provocation is Weatherston v R [2011] NZCA 276 (17 June 2011), a case which was a major motivation for the repeal of this partial defence in New Zealand. Our national sense of horror is such that we have yet to replace it with anything like loss of control. The difference between Lewis and Weatherston is small (I mean here that in each the defendant claimed to have lost self-control as a result of his sensitivity to the consequences of a terminated sexual relationship), and it is likely that if the judge in Weatherston had refused to leave provocation with the jury the Court of Appeal would have upheld that decision, and, in that event, our crisis over the existence of this partial defence may well not have occurred.


Although the best barristers say very little, I, by way of contrast, can add a bit about provocation. Earlier I mentioned Attorney-General for Jersey v Holley [2005] UKPC 23 (see the entry for 5 July 2005), and it is worth calling to mind the two-stage inquiry by which courts address issues of provocation. First, what level of provocation can the defendant properly claim to have experienced? This requires considering how a reasonable person with the defendant's characteristics would have felt the provocative words or conduct. It is a mix of objective and subjective considerations. No doubt one could fairly say it requires a considerable exercise of imagination to assess. Second, given the level of provocation assessed in that way, does it exceed the level that a reasonable person ought to be able to tolerate without losing self-control? This is an objective question. These questions  can be modified when the issue is whether provocation is a live issue in the case:  is there evidence of acts or words that could reasonably be taken as requiring an exercise of self-control by the defendant, and, if so, could it reasonably be concluded that the exercise of self-control so required was beyond the ability of a reasonable person to exercise? This latter question determines whether a loss of self-control could have been through provocation as opposed to being the result of malice.

How do the new "loss of control" provisions applicable to England and Wales, referred to above, deal with these issues? On the first question, the s 55 definition of "qualifying trigger" sets the objective standards for the nature of the provocative act or words (serious violence, extremely grave circumstances, justifiable sense of being seriously wronged), and the subjective requirements are in s 54 (loss of self-control caused by a qualifying trigger). The second question, whether a reasonable person would have lost self-control if subjected to the level of provocation experienced by the defendant, appears in s 54(1)(c), which sets the standard as that of a person of the defendant's age and sex and who has "a normal degree of tolerance and self-restraint". Overall, and I only generalise because there will be a lot of interpretative issues, this legislation has the important effect of ensuring that only seriously provocative acts or words can be the basis for this qualified defence.

The unsaid unchartable universe

The more one says, the more one does not say. The universe of discourse is infinite. This is why attacks on reasoned judge-alone decisions must be constrained: a judge cannot anticipate every possible attack that might be made by imaginative appeal counsel.

It is necessary to avoid creating an "unchartable universe of appellate review", as Abella J so picturesquely put it in R v O'Brien 2011 SCC 29 (9 June 2011), writing for herself, McLaughlin CJ, Deschamps, Rothstein, and Cromwell JJ.

So, if a judge says he relies "entirely" on particular evidence, this is not to be taken to mean he was unconsciously influenced by other, inadmissible, evidence. It means the opposite: he deliberately ignored what was inadmissible.

"17. A trial judge has an obligation to demonstrate through his or her reasons how the result was arrived at. This does not create a requirement to itemize every conceivable issue, argument or thought process. Trial judges are entitled to have their reasons reviewed based on what they say, not on the speculative imagination of reviewing courts. As Binnie J. noted in R. v. Sheppard, 2002 SCC 26 (CanLII), 2002 SCC 26, [2002] 1 S.C.R. 869, at para. 55, trial judges should not be held to some "abstract standard of perfection"."

Even so, there can be room for disagreement on appeal about what the judge meant, as occurred in this case. The way to avoid this is for judges to be specific about their treatment of inadmissible evidence, even if counsel had not objected to that evidence at the trial.

Raising the bar

For a collection of articles illustrating brilliant scholarship in our areas of interest, see the Journal of Commonwealth Criminal Law, available at the website of the Association of Commonwealth Criminal Lawyers.

New complications for old

Mahomed v R [2011] NZSC 52 (19 May 2011) shows that the law of similar fact evidence is still contentious. It has recently been reformed, by calling it propensity evidence and by enacting it. Sections 40-43 of the Evidence Act 2006 [NZ] replace the common law on this topic.

In Mahomed the Supreme Court split 3-2 over what items of evidence were included as propensity evidence. The majority focused narrowly on one incident, and the minority said it was artificial to take an "atomistic" approach [73] and instead the overall pattern of events had to be looked at. The same split occurred on whether the propensity evidence was admissible: the majority said the one incident was only admissible on one of the four counts, whereas the minority said the overall pattern of events was admissible on all counts.

Further, the judges split into the same groups on whether it was appropriate to consider in detail the kinds of directions that juries should be given. The majority chose not to go into this, whereas the minority analysed the use and risks of propensity evidence, when a direction should be given and what it should say.

Conveniently, the consistency of the split between the members of the Court made it only necessary to deliver two judgments. The majority judgment of Elias CJ, Blanchard and Tipping JJ was delivered by Tipping J, and for the minority William Young J delivered the judgment of himself and McGrath J.

As the majority found there had been a miscarriage of justice arising from the way the judge had instructed the jury (he had followed a Court of Appeal ruling in this case – R v Mahomed [2009] NZCA 477 - which had held that the evidence was admissible on all counts), it had to consider whether to apply the proviso. As it happened, doing this by applying R v Matenga [2009] NZSC 18 (an approach I have criticised here, for example on 20 July 2009 and 1 January 2010) involved no greater discussion of the prosecution case that would the more conventional method for deciding conviction appeals which asks whether there was a real possibility that the error at trial affected the verdict (see Fraser v HM Advocate [2011] UKSC 24, discussed here on 26 May 2011).

The Mahomed minority's analysis of types of propensity evidence, identifying categories and sub-categories, and allowing that some instances may require swapping between categories depending on the strength of the evidence, leaves one wondering if the subject is set to become, once more, over-academicised. Complications arising from "coincidence" reasoning (eg at [51]) tend to confuse rhetoric with substance. When a prosecutor argues that either the defendant is guilty or that he is the victim of an amazing coincidence through being falsely accused by independent complainants, that rhetoric is really a reflection of the denominator of the Bayesian likelihood ratio: the low probability of getting the accusations on the assumption that the defendant is innocent.

The prosecutor's argument is sound, but it does not generate a new category of propensity evidence (see [85(a)], and [87] where Hudson v R [2011] NZSC 51 is said in footnote 50 not to be an appropriate case for coincidence reasoning). But coincidence is just another word for "low probability" and as para [59] of Hudson points out coincidence reasoning there was unnecessary as it would have duplicated ("elaborated") what the judge had told the jury. The prosecution would have said there that as the defendant had a motive, commission of the offence by someone else would by an unlikely coincidence. It comes down to the low probability of getting the evidence of motive on the assumption of innocence, and the high probability of getting it on the assumption of guilt.

There was unanimity on the relationship between the balancing exercises in s 8 and s 43 which both address probative value and prejudicial effect. In the context of propensity evidence, s 43 is the sole balancing exercise: majority at [5], minority at [66-67]. The minority do, however, accept a theoretical case of equal balance, but I think that is a misconception. The balancing metaphor in both sections does not work like a weighing of commodities. What needs to be avoided is a real risk of unfairness to the defendant, and probative evidence can "outweigh" that risk if admission of the evidence does not give rise to that risk. The Court of Appeal recognised this in  Vuletich v R [2010] NZCA 102 per Glazebrook J at [27] and Randerson J at [96], rejecting a suggestion that had been made in Stewart (Peter) v R [2008] NZCA 429 by Baragwanath J to the effect that highly probative evidence could only be inadmissible if it gave rise to a level of illegitimate prejudice that was even greater. It would have been useful for the Supreme Court to have addressed this fundamental issue in Mohamed.

Non-disclosure and trial fairness

An appellate court often has to ask whether a trial was fair. Statutory requirements for allowing conviction appeals usually include "a miscarriage of justice". What does that phrase mean for the purposes of assessing whether the trial was fair? The United Kingdom Supreme Court addressed this in Fraser v HM Advocate [2011] UKSC 24 (25 May 2011).

In this case information had not been disclosed to the defence, and had it been disclosed the conduct of the case for each side would have been different. Therefore, non-disclosure here went to the question of trial fairness [32].

The question of trial fairness is not answered by considering what verdict the appellate judges would have reached at a hypothetical trial [38]:

"One cannot, of course, avoid making some assumptions as how the trial might have been conducted if the material had been disclosed to the defence. It will always be a question of degree as to how far it is proper to go in carrying out that exercise. But the purpose of doing this is to assess the extent to which, having regard to the way the case was conducted by the Crown, the material would have weakened the Crown case or strengthened the case for the defence. It is on the case as presented at the trial that the court must concentrate, rather than the case as it might have been presented. It is not for us to speculate as to what the case might have been, much less how the jury would have reacted to it. What the Crown asks us to do, and what it persuaded the Appeal Court to do, was to consider the case on the basis that the discovery of the rings on 7 May was indicative of the appellant's guilt for completely different reasons from those advanced at the trial. In effect we were being asked to deal with the case as if we were a new jury trying the case for the first time. This is not permissible. Our task is quite different but entirely clear. As the Appeal Court said in McCreight v H M Advocate [2009] HCJAC 69, 2009 SCCR 743, para 95, it is not the court's task to decide what the outcome of the trial would have been if the trial had been conducted on an entirely different basis. We must ask ourselves whether, in the light of the undisclosed evidence, there is a real possibility that the jury at this trial would have arrived at a different verdict."

The trial would have been unfair if there was a real possibility that had the error not occurred the jury would have reached a different verdict.

The case illustrates how an appellate court should apply this test. At trial the prosecution had alleged that the defendant's guilt of his wife's murder was demonstrated by her rings that could only have been found where they were if he had removed them from her corpse. The non-disclosed evidence was that the rings had been at that location before she died.

"[39] The proposition that the appellant had returned the rings to the bathroom on 7 May was, as the Advocate Depute said in his address to the jury, the cornerstone of the Crown's case. It is clear, in view of the direction that was then given to them by the trial judge, that the jury must have concluded that the appellant put the rings in the bathroom on 7 May. This was the basis for the Crown's theory that he had obtained the rings from the deceased's dead body and had placed them in the bathroom to create the impression that she had left the matrimonial home with the intention of turning her back on the life that she had had there. This theory would have been undermined by the evidence of PC Lynch and WPC Clark. It would have been challenged by lines of cross-examination of the Crown witnesses that were never developed at the trial, and by questions that were never put to the appellant in chief or in re-examination. The point could have been made that it was improbable that, if the rings were in the bathroom on 28 and 29 April when the police visited the house, the appellant would have removed them and then chosen to return them on 7 May. The theory that he removed them from the dead body would, if the evidence of PC Lynch and WPC Clark were to be accepted, have been untenable. These and other arguments that the defence would have been able to develop would have struck at the heart of the case that the Crown presented. The trial would have been significantly different had the material that was not disclosed been available. There is a real possibility that this would have been sufficient to raise a reasonable doubt about the Crown's case that the appellant returned the rings to the bathroom on 7 May. If that were so, the jury's verdict would be bound in view of the trial judge's direction to have been different."

It was the real possibility of a different verdict that made the trial unfair.

Non-disclosure significantly affected the course of the trial. This was not a case of freshly discovered evidence, although I think the difference should be immaterial because the ultimate question is whether there is a real possibility that the omission affected the verdict.

I have suggested that all conviction appeals raise issues of trial fairness. This is because a fair trial is one where the law is properly applied to facts that are determined impartially. "Impartially" is used in a wide sense to include actual and apparent bias as well as inaccuracy. Even appeals challenging jurisdiction raise fairness in this sense, as without jurisdiction the law is not properly applied. Fresh evidence appeals also concern fairness, as the newly discovered evidence may demonstrate a real possibility that the verdict was wrong. There can be unfairness even if the verdict was not affected, where the law was not properly applied, but this was not that sort of appeal.

I have recently (7 April 2011) mentioned misuse of hypotheticals by appellate courts, and have also criticised the usurpation of the jury role by appeal judges, for example here (9 July 2009) and here (25 June 2007), and here (16 January 2006).

Writing for judges

Do not even consider living a day longer without reading these interviews with the Justices of the United States Supreme Court: The Scribes Journal of Legal Writing (2010) vol 13, available here.

Because brevity wins, I leave it at that, except to mention this teaser by Roberts CJ:

"What the academy is doing, as far as I can tell, is largely of no use or interest to people who actually practice law."

Avoiding the paperwork

The United States Supreme Court has handed police what may seem to be a legal way of searching homes without the need to obtain warrants: Kentucky v King USSC No 09-1272 (16 May 2011). When should a defendant's suspicious behaviour be ignored when the adequacy of grounds for a warrantless search is being assessed by a court?

The fundamental requirement is that there should be reasonable grounds for a search. The police need not apply for a search warrant, even if they have grounds to obtain one. The opinion of the Court, delivered by Alito J and joined by Roberts CJ, Scalia, Thomas, Kennedy, Breyer, Sotomayor and Kagan JJ (Ginsburg J delivered a dissenting opinion), mentioned five reasons for not requiring a warrant. They are set out at p 12 of the slip opinion. I summarise:

1. The police may wish to speak to the occupier to see if it is worth getting a warrant.
   
2. The police may want to ask the occupier for consent because that would be easier.
   
3. They may want more evidence before submitting a marginal application for a warrant.
   
4. They may want evidence to justify a broader warrant than they currently have grounds for.
   
5. They may not want to disclose that they have grounds for a warrant because that might alert other suspects.
   

These were held to be legitimate law enforcement strategies. There will, I acknowledge, be occasions when resort to them is reasonable. It may be absurd to require the police to hold off conducting a search while they apply for a warrant, as indeed it would have been on the facts of the present case. However, the danger is that the safeguards involved in the warrant procedure will be cast aside in favour of expedience on the basis of an imagined urgency. It would be easy for the police to claim that they heard what seemed to be an attempt to destroy evidence, and a citizen subject to warrantless search of his home would be unlikely to be able credibly to challenge its legality. It would be inappropriate for a judge to take any but a very cautious approach to evaluating the credibility of police claims of such urgency.


Nor is it appropriate to pretend that the police may always behave as if they were private citizens as far as door-knocking is concerned, as the majority do at p 16. Private citizens are not state agents collecting evidence to prosecute suspected offenders. It is disingenuous for the Court to hold that occupiers may "stand on their constitutional rights" and not answer the door or allow police entry, but if they "elect to attempt to destroy evidence [they] have only themselves to blame for the warrantless exigent-circumstances search that may ensue."

One would think that, on this approach, a refusal by an occupier to allow police entry would be understood by the police to be an attempt to preserve an opportunity to destroy evidence, and would therefore be justification for a warrantless entry and search.

The opportunities for abuse of powers in this context are such that, for people who regard the Fourth Amendment as a proper restraint on executive power, Ginsburg J's dissent may be considered the sole voice of reason in this case.

But the case is not about random door-knocking by the police. The police believed that the smell of cannabis was coming from a specific apartment. 

The ratio of this case is that in deciding whether a warrantless search was reasonable the court will need to consider all the circumstances, and unreasonable police conduct does not give rise to reasonable grounds. This is unobjectionable as a legal rule. If it had been unreasonable for the police to knock on the door in this case, the police would not have been able to rely on subsequent inferences they drew as to risk of destruction of evidence (the exigency). There was no evidence here (pp 17-18) that the police had acted unreasonably prior to entry, so (p 19) the exigency justified the warrantless entry. This was on the Court's assumption, for the purposes of argument (p 17), that there was in fact an exigency here. This assumption was only necessary if, without the exigency, there would have been inadequate grounds for entry. So the police here had reasonable grounds for knocking on the door but, at that point, not for entry, but when (if) the exigency occurred they had (would have had) reasonable grounds for entry. The case was remanded to the Kentucky Supreme Court for further proceedings not inconsistent with the Court's opinion.

A strange thing about this case is why exigent circumstances were relevant. If the police smell cannabis ("marijuana") smoke and establish that it is coming from private property, they would have reasonable grounds to believe that an offence was being committed and so could search without warrant:  for example, R v Gurnick [1999] NZCA 19, (1999) 16 CRNZ 513 (CA). But the position is different in the US, where there is a stronger preference for grounds to be assessed by a neutral official: Johnson v United States, 333 U.S. 10 (1948). In that case the smell of opium from a hotel room, without the risk of a suspect fleeing, or of destruction of evidence, was not grounds for a warrantless search.