The stay cases generally fall into two categories: 1) where state conduct compromises the fairness of an accused’s trial (the “main” category); and 2) where state conduct creates no threat to trial fairness but risks undermining the integrity of the judicial process (the “residual” category). In R v O’Connor, Justice L’Heureux-Dube stated, “It must always be remembered that a stay of proceedings is only appropriate “in the clearest of cases”, where the prejudice to the accused’s right to make full answer and defence cannot be remedied or where irreparable prejudice would be caused to the integrity of the judicial system if the prosecution were continued.” In Tobiass, the Supreme Court noted that these “exceptional cases” that merited a stay will be relatively rare. The Court then set out some general propositions in relation to the nature of the remedy:
… A stay is not a form of punishment. It is not a kind of retribution against the state and it is not a general deterrent. If it is appropriate to use punitive language at all, then probably the best way to describe a stay is as a specific deterrent — a remedy aimed at preventing the perpetuation or aggravation of a particular abuse. Admittedly, if a past abuse were serious enough, then public confidence in the administration of justice could be so undermined that the mere act of carrying forward in the light of it would constitute a new and ongoing abuse sufficient to warrant a stay of proceedings. However, only an exceedingly serious abuse could ever bring such continuing disrepute upon the administration of justice. It is conceivable, we suppose, that something so traumatic could be done to an individual in the course of a proceeding that to continue the prosecution of him, even in an otherwise unexceptionable manner, would be unfair. Similarly, if the authorities were to fabricate and plant evidence at the scene of a crime, the continued pursuit of a criminal prosecution might well be damaging to the integrity of the judicial system.
The test for stay for main and residual category of cases
In R. c. Piccirilli, Moldaver J. for the majority of the Supreme Court of Canada explained that the the test used to determine whether a stay of proceedings is warranted is the same for both categories and consists of three requirements: 1) There must be prejudice to the accused’s right to a fair trial or the integrity of the justice system that “will be manifested, perpetuated or aggravated through the conduct of the trial, or by its outcome”; 2) There must be no alternative remedy capable of redressing the prejudice; and 3) Where there is still uncertainty over whether a stay is warranted after steps 1) and 2), the court is required to balance the interests in favour of granting a stay, such as denouncing misconduct and preserving the integrity of the justice system, against “the interest that society has in having a final decision on the merits”. The test is the same for both categories because concerns regarding trial fairness and the integrity of the justice system are often linked and regularly arise in the same case. Having one test for both categories creates a coherent framework that avoids “schizophrenia” in the law. But while the framework is the same for both categories, the test may — and often will — play out differently depending on whether the “main” or “residual” category is invoked. Commencing with the first stage of the test, when the main category is invoked, the question is whether the accused’s right to a fair trial has been prejudiced and whether that prejudice will be carried forward through the conduct of the trial; in other words, the concern is whether there is ongoing unfairness to the accused. By contrast, when the residual category is invoked, the question is whether the state has engaged in conduct that is offensive to societal notions of fair play and decency and whether proceeding with a trial in the face of that conduct would be harmful to the integrity of the justice system. To put it in simpler terms, there are limits on the type of conduct society will tolerate in the prosecution of offences. At times, state conduct will be so troublesome that having a trial — even a fair one — will leave the impression that the justice system condones conduct that offends society’s sense of fair play and decency. This harms the integrity of the justice system. In these kinds of cases, the first stage of the test is met.
In respect of the first stage, while it is generally true that the residual category will be invoked as a result of state misconduct, this will not always be so. Circumstances may arise where the integrity of the justice system is implicated in the absence of misconduct. Repeatedly prosecuting an accused for the same offence after successive juries have been unable to reach a verdict stands as an example, as does using the criminal courts to collect a civil debt . Moreover, in a residual category case, regardless of the type of conduct complained of, the question to be answered at the first stage of the test is the same: whether proceeding in light of the impugned conduct would do further harm to the integrity of the justice system. The court must still consider whether proceeding would lend judicial condonation to the impugned conduct.
At the second stage of the test, the question is whether any other remedy short of a stay is capable of redressing the prejudice. Different remedies may apply depending on whether the prejudice relates to the accused’s right to a fair trial (the main category) or whether it relates to the integrity of the justice system (the residual category). Where the concern is trial fairness, the focus is on restoring an accused’s right to a fair trial. Here, procedural remedies, such as ordering a new trial, are more likely to address the prejudice of ongoing unfairness. Where the residual category is invoked, however, and the prejudice complained of is prejudice to the integrity of the justice system, remedies must be directed towards that harm. It must be remembered that for those cases which fall solely within the residual category, the goal is not to provide redress to an accused for a wrong that has been done to him or her in the past. Instead, the focus is on whether an alternate remedy short of a stay of proceedings will adequately dissociate the justice system from the impugned state conduct going forward. For example, in R v Nasogaluak, the Supreme Court of Canada found that, in the circumstances of that case, a reduction in sentence was an appropriate remedy for an excessive use of police force in breach of the appellant’s s. 7 Charter rights. Justice Fish, writing for the Court, held:
I do not foreclose, but do not need to address in this case, the possibility that, in some exceptional cases, sentence reduction outside statutory limits, under s. 24(1) of the Charter, may be the sole effective remedy for some particularly egregious form of misconduct by state agents in relation to the offence and the offender. In that case, the validity of the law would not be at stake, the sole concern being the specific conduct of those state agents.
Finally, the balancing of interests that occurs at the third stage of the test takes on added significance when the residual category is invoked. The balancing need only be undertaken where there is still uncertainty as to whether a stay is appropriate after the first two parts of the test have been completed. When the main category is invoked, it will often be clear by the time the balancing stage has been reached that trial fairness has not been prejudiced or, if it has, that another remedy short of a stay is available to address the concern. In those cases, no balancing is required. In rare cases, it will be evident that state conduct has permanently prevented a fair trial from taking place. In these “clearest of cases”, the third and final balancing step will often add little to the inquiry, as society has no interest in unfair trials.
However, when the residual category is invoked, the balancing stage takes on added importance. Where prejudice to the integrity of the justice system is alleged, the court is asked to decide which of two options better protects the integrity of the system: staying the proceedings, or having a trial despite the impugned conduct. This inquiry necessarily demands balancing. The court must consider such things as the nature and seriousness of the impugned conduct, whether the conduct is isolated or reflects a systemic and ongoing problem, the circumstances of the accused, the charges he or she faces, and the interests of society in having the charges disposed of on the merits. Clearly, the more egregious the state conduct, the greater the need for the court to dissociate itself from it. When the conduct in question shocks the community’s conscience and/or offends its sense of fair play and decency, it becomes less likely that society’s interest in a full trial on the merits will prevail in the balancing process. But in residual category cases, balance must always be considered.
 R. c. Piccirilli, 2014 SCC 16 at para 31 [Piccirilli].
  4 SCR 411.
 R v O’Connor,  4 SCR 411 at paragraph 82.
 Canada (Minister of Citizenship and Immigration) v Tobiass,  3 SCR 391 at paras 91, 93 and 97 [Tobiass].
 Ibid., at para 91.
 Tobiass, supra note 4 at para 96.
 Supra note 1.
 Piccirilli. supra note 1 at para 32
 Ibid., at para 33
 Ibid., at para 34
 Piccirilli. supra note 1 at para 35
 Ibid., at para 37
 Ibid., at para 38
 Piccirilli. supra note 1 at para 39
  1 SCR 206.
 Ibid., at para 64.
 Piccirilli. supra note 1 at para 40
Piccirilli. supra note 1 at para 41