|This page was last substantively updated or reviewed January 2021. (Rev. # 86612)|
A mistrial is a remedy where it "is necessary to prevent a miscarriage of justice". A miscarriage can arise where "a trial is unfair, or when the trial has the appearance of unfairness, viewed by a well-informed, reasonable person considering the whole of the circumstances".
A mistrial will also arise where there is an apprehension of bias.
- Pre-Condition to a Mistrial
A declaration of a mistrial "should only be granted as a last resort, in the clearest of cases and where no remedy short of that relief will adequately redress the actual harm occasioned." In a jury trial, a mistrial can only be ordered if the prejudice cannot be remedied by a jury instruction. The decision to grant an application for a mistrial is discretionary.
An appellate court should only intervene where the decision "is so clearly wrong as to amount to an injustice". 
For an application for a mistrial the test is "whether the appellant’s ability to make full answer and defence has been impaired." 
Other remedies, such as mid-trial instructions, should be considered before a mistrial is granted.
- Impairment of Full Answer and Defence
The impairment of full answer and defence is not limited to the accused's ability to respond to the merits of the case but also the ability to make "process-oriented" challenge to the proceedings.
- Mistrial After Judge's Verdict
A trial judge who convicts an accused but has not yet sentenced him is not functus in respect of the charge any may still vacate the finding before sentencing.
- Mistrial After Jury Verdict
The authority of a judge to order a mistrial after a jury renders a verdict is "extremely limited".
Interference with a jury verdict is permitted where:
- the jury does not render the verdict it intended; or
- where the accused wants to raise the defence of entrapment.
Where an exception does not apply, the judge is functus.
Ineffective legal assistance is not a valid ground for a mistrial after verdict.
- Timing of Application
Courts have jurisdiction to grant a mistrial even after a conviction but before sentencing.
- Scheduling of a Re-Trial
A retrial should be scheduled "without further delay". Only a "short period" of delay will be expected. Anything longer may open the possibility of a s. 11(b) Charter delay.
- Mistrial as Abuse of Process
There is some suggestion that the Crown seeking a mistrial to provide an opportunity to strengthen the case against the accused and cover for negligent preparations may be considered abusive and warrant a stay under s. 7 of the Charter.
R v Burke, 2002 SCC 55 (CanLII),  2 SCR 857, per Major J, at para 75
see also R v Chiasson, 2009 ONCA 789 (CanLII), 258 OAC 50, per curiam
R v Toutissani, 2007 ONCA 773 (CanLII),  OJ No 4364, per MacPherson JA
R v Khan, 2001 SCC 86 (CanLII),  3 SCR 823, per Arbour J, at para 27
R v Vader, 2016 ABQB 625 (CanLII), per DRG Thomas J, at para 10
R v GC, 2018 ONCA 392 (CanLII), 146 WCB (2d) 332, per curiam, at para 3
Khan, supra, at para 79
GC, supra, at para 3
Khan, supra, at para 79
R v Burke, 2002 SCC 55 (CanLII), 164 CCC (3d) 385, per Major J, at para 74
see also Reasonable Apprehension of Bias
Toutissani, ibid., at para 9
R v Karim, 2010 ABCA 401 (CanLII), 493 AR 312, per curiam, at para 27 - a mistrial should be allowed only in "the clearest of cases where there is no other way to save the trial"
R v GC, 2018 ONCA 392 (CanLII), 146 WCB (2d) 332, per curiam, at para 4 ("A mistrial is a remedy of last resort...")
R v Truscott, 1960 CanLII 474 (ON CA), 126 CCC 136, per Porter CJ
R v Burnett, 2014 MBQB 23 (CanLII), per Menzies J, at para 19
R v Grant (I.M.), 2009 MBCA 9 (CanLII), 240 CCC (3d) 462, per Chartier JA, at para 69
GC, supra, at para 4
- Grant, ibid., at para 69
- R v T(LA), 1993 CanLII 3382 (ON CA),  OJ No 1605, 84 CCC (3d) 90, per Lacourciere JA, at para 8
- Toutissani, supra
- R v Sandeson, 2020 NSCA 47 (CanLII), per Farrar JA
R v Henderson, 2004 CanLII 33343 (ON CA), 189 CCC (3d) 447, per Feldman JA (3:0), at para 29 ("...where a trial judge convicts an accused but has not yet sentenced him or her, the trial judge is not functus in respect of that charge, and can, in exceptional circumstances, vacate the adjudication of guilt before sentencing...")
R v Lessard, 1976 CanLII 1417 (ON CA), 30 CCC (2d) 70, per Martin JA, at pp. 73 to 75
- Henderson, ibid. ("A judge’s jurisdiction to alter a jury’s verdict, order a stay or declare a mistrial after a jury verdict is extremely limited.")
- R v Miguel Orlando Zavala-Martinez, 2019 ONSC 1087 (CanLII), per Allen J, at para 8
- Zavala-Martinez, ibid.
- Zavala-Martinez, ibid., at para 12
- R v Andersen, 2018 BCSC 587 (CanLII), per Weatherill J
R v Brace, 2010 ONCA 689 (CanLII), 261 CCC (3d) 455, per Juriansz JA, at para 15
see also Right to a Trial Within a Reasonable Time
R v D(TC), 1987 CanLII 6777 (ON CA), 38 CCC (3d) 434, per Martin JA, at p. 447 (CCC) (" In my view, however, s. 7 of the Charter constitutionalizing the requirement of "fundamental justice" might, in some circumstances, bar a second trial where the first trial has been improperly terminated. By way of example only, I consider that if, upon a breakdown of the Crown's case, a judge were to declare a mistrial in order to give the prosecution an opportunity to strengthen its case against the accused by endeavouring to find additional witnesses thereby depriving the accused of an acquittal where the Crown's initial preparation had been negligent, a second trial in those circumstances would contravene the principles of fundamental justice. ")
see also R v Pan, 1999 CanLII 3720 (ON CA), 134 CCC (3d) 1, per McMurtry CJ, Osborne, Labrosse and Charron JJA aff'd R v Pan; Sawyer, 2001 SCC 42 (CanLII),  2 SCR 344
Consequence of Mistrial on Future Matters
Where a mistrial is declared, the rulings on pre-trial motions will generally still apply if the prosecution is re-initiated.
Section 653.1 states:
This section is considered a "departure from previous authority from the Supreme Court of Canada to the effect that a trial judge is not bound by interlocutory rulings made at an earlier trial". Its purpose is to ensure that the consequences of a mistrial are minimized and that cretian issues do not have to be re-litigated on retrial.
Section 653.1 applies to rulings that relate to (1) disclosure; (2) admissibility of evidence; or (3) the Charter.
- Presumptions Relating to Prior Rulings
This presumption to maintaining prior ruling can be rebutted on a balance of probabilities where it is in the "interests of justice".
- Interests of Justice
"Interests of justice" are not limited to the interest of the parties but also the "broad-based societal concerns".
Rebuttal of the presumption can include considerations such as:
- whether any new evidence will be tendered on the proposed rehearing;
- whether any new arguments will be advanced on the proposed rehearing and the apparent merit, if any, of those arguments;
- the interests of the parties, including any articulable prejudice fostered or perpetuated by the inability to relitigate any issue previously decided;
- the public interest in the timely and efficient conduct of criminal trial proceedings and avoidance of unnecessary and duplicative proceedings;
- any changes in the legal principles governing the ruling on which relitigation is proposed;
- the nature of the evidentiary record on the basis of which the prior ruling was made, as for example, viva voce testimony; agreed statement of facts; transcripts of testimony given elsewhere and any differences in the record proposed for relitigation;
- the nature of the issue(s) involved in the prior ruling and proposed relitigation;
- the possibility of inconsistent rulings; and
- any other circumstances relating to the balance of the subsequent trial proceedings that may have an impact on the continued applicability of the prior rulings.
- R v Lee, 2002 CanLII 8304 (ON CA), 170 CCC (3d) 225, per MacPherson JA
R v Davis, 2012 ONSC 5526 (CanLII), per Baltman J, at para 14
R v Victoria, 2018 ONCA 69 (CanLII), 359 CCC (3d) 179, per curiam (3:0)
Victoria, ibid., at para 51
- Victoria, ibid., at para 52
- Victoria, ibid., at para 53
- Victoria, ibid., at para 55
Circumstances for a Mistrial
A mistrial may be ordered where:
- an opening address and cross-examination refers to a confession that is later determined inadmissible.
A mistrial will not be ordered where the accused fires trial counsel mid-trial and the new counsel wishes to have re-done the trial in a different manner. There is no right to start over again with new counsel.