The followingis a non-exhaustive list of when the Court of Appeal will exercise its appellate jurisdiction, a list I will be adding to in future blog posts. 

Admissibility

A party, having tendered evidence without objection at trial, cannot then appeal the admissibility of that evidence when it does not have the desired effect.

R. v. Hackett, 2006 CanLII 10949 (ON CA), at para. 7.
Argument Advanced for first time on Appeal

It is the general practice of the Court of Appeal not permit the advancement of grounds for the first time on appeal. Argument advanced for the first time on appeal will typically lack not only an evidentiary foundation, but also the critical findings of fact necessary for a judicial determination of its merits.

Appeals from Acquittal
On appeals from an acquittal, the Crown is limited under s. 676(1)(a) of the Criminal Code to grounds of appeal that involve questions of law alone. 

An appeal court  ought to be slow to interfere with a judge’s handling of the evidence and findings on credibility as they generally do not raise questions of law alone.
R. v. J.M.H., 2011 SCC 45, [2011] 3 S.C.R. 197, at para. 24. 
A Court of Appeal’s finding of a legal error at trial does not, on its own, justify setting aside the acquittals and ordering a new trial.

An appellant must demonstrate an error of law has been made, and, to a reasonable degree of certainty, that the error was material to the trial judge’s verdict. 

R. v. George, 2017 SCC 38 (CanLII), at para. 27.
Credibility findings

Assessments of credibility are entitled to strong deference on appeal. An appellate court may only intervene if the credibility findings are based on palpable and overriding error.
R. v. Sanderson, 2017 ONCA 470 (CanLII), at para. 18.
Fresh Evidence on Appeal

Under s. 683(1) of the Criminal Code,  an appellate court has a broad discretion to receive evidence on appeal “where it considers it in the interests of justice” to do so. The burden is on the applicant to establish that the fresh evidence is admissible.

Although the overriding test for the admission of fresh evidence is “the interests of justice”, appellate courts have structured their discretion under this broad standard by prescribing a specific set of criteria to be addressed. 

The leading Supreme Court of Canada case, decided nearly 40 years ago, is Palmer v. The Queen, 1979 CanLII 8 (SCC), [1980] 1 S.C.R. 759. A decade ago in Truscott (Re), 2007 ONCA 575 (CanLII), 225 C.C.C. (3d) 321, at para. 92, the Court of Appeal for Ontario reformulated the Palmer test. It consists of three criteria, each set out by a question:
1. Admissibility criterion: Is the evidence admissible under the operative rules of evidence?

2. Cogency criterion: Is the evidence sufficiently cogent in that it could reasonably be expected to have affected the verdict?

3. Due diligence criterion: What is the explanation offered for the failure to adduce the evidence at trial and should that explanation affect the admissibility of the evidence? 

The admissibility of hearsay evidence (eg.  a prior inconsistent statement), is a question of law.  The factual findings that go into that determination are entitled to deference.
R. v. Youvarajah, 2013 SCC 41, [2013] 2 S.C.R. 720.

Jury Charge

On appeal, the standard of review is adequacy, not perfection. An appellate court’s approach is “functional”. It assesses the adequacy of the charge in the light of its purpose. Even if a trial judge strays from the ideal, the fundamental question an appellate court must ask is: has the jury been “left with a sufficient understanding of the facts as they relate to the relevant issues?” 

See R. v. Jacquard, [1997] 1 S.C.R. 314, at para. 14.
Or—put another way—is the appellate court satisfied “that the jurors would adequately understand the issues involved, the law relating to the charge the accused is facing, and the evidence they should consider in resolving the issues”. 

See R. v. Cooper, [1993] 1 S.C.R. 146, at p. 163.

 If the answer to either question is “yes”, then the charge will be upheld on appeal, despite any imperfections. If the answer is “no”, then the accused will have been denied a fair trial and any convictions must be set aside. 
Error of Law

The adequacy of the evidence to discharge the Crown’s burden of satisfying the demanding standard of proof in a criminal case does not raise a question of law.

R. v. J.M.H., 2011 SCC 45 (CanLII), [2011] 3 S.C.R. 197, at para. 39; R. v. B. (R.G.), 2012 MBCA 5, 287 C.C.C. (3d) 463, at paras. 34 and 36; R. v. K.S., 2017 ONCA 307.
No legal error arises from mere disagreements over factual inferences or the weight of evidence.
J.M.H., at para. 28.
In R. v. J.M.H., the Supreme Court of Canada identified four, non-exhaustive, categories of cases in which alleged shortcomings in a trial judge’s assessment of the evidence constitute an error of law, thereby allowing appellate review of an acquittal.  Justice Cromwell, writing for the court, described these categories as follows, at paras. 25-32:

1) it is an error of law to make a finding of fact for which there is no supporting evidence. However, a conclusion that the trier of fact has a reasonable doubt is not a finding of fact for the purposes of this rule. Rather, it is a conclusion that the standard of persuasion beyond a reasonable doubt has not been met;

2) the legal effect of findings of fact or of undisputed facts may give rise to an error of law;

3) an assessment of the evidence based on a misapprehension or misdirection concerning a legal principle is an error of law; and

4) a failure to consider all the evidence in relation to the ultimate issue of guilt or innocence is also an error of law.
Section 24(1) of the Charter

Appellate review of a remedy ordered or refused, under s. 24(1) of the Charter is warranted only where a trial judge misdirects her or himself in law, commits a reviewable error of fact, or renders a decision that is “so clearly wrong as to amount to an injustice”:

R. v. Bellusci, 2012 SCC 44, [2012] 2 S.C.R. 509, at paras. 17-19; Babos, at para. 48; Regan, at paras. 117-118; Tobiass, at para. 87; R. v. Gowdy, 2016 ONCA 989, at para 65.
Section 11(b) of the Charter

The characterization of various periods of time is reviewed on a standard of correctness, as is the ultimate decision whether the delay was unreasonable.

 See e.g. R. v. Cranston (2008), 2008 ONCA 751 (CanLII), 244 O.A.C. 328 (C.A.); R. v. Quereshi (2004), 2004 CanLII 40657 (ON CA), 190 C.C.C. (3d) 453 (Ont. C.A.)

 However, the underlying findings of fact are reviewed on the standard of palpable and overriding error.  

R. v. Schertzer, 2009 ONCA 742, at para. 71.
Section 24(2) of the Charter

The trial judge’s ruling admitting or excluding evidence pursuant to s. 24(2) is entitled to deference absent

·         an error in law or principle,

·         material misapprehension of the evidence relevant to the ruling, or

·         an unreasonable conclusion (eg. by considering irrelevant and impermissible factors: R. v. Strauss, 2017 ONCA 628, at para. 38.)
R. v. Harris, 2007 ONCA 574 (CanLII), 87 O.R. (3d) 214, at para. 50; R. v. Côté, 2011 SCC 46, [2011] 3 S.C.R. 215, at para. 44. 
Trial judges have a broad discretion to impose the sentence they consider appropriate within the limits established by law.

R. v. Shropshire, 1995 CanLII 47 (SCC), [1995] 4 S.C.R. 227 at ¶ 46;

R. v. Nasogaluak, 2010 SCC 6 (CanLII) at ¶ 43-46. 

The Court of Appeal should not intervene absent

·         an error in principle,

·         failure to consider a relevant factor,

·         overemphasis of the appropriate facts, or

·         a sentence that is demonstrably unfit.

 R. v. Proulx, 2000 SCC 5 (CanLII) at ¶ 123. 

Any error that may be identified by an appellate Court will only justify intervention if that error had an impact on the sentence ordered.

R. v. Lacasse, 2015 SCC 64 (CanLII) at ¶ 41, 43-44.

In the case of an appeal from a sentence, the power of an appellate court to substitute a sentence for the one imposed by the trial judge is provided for in s. 687 of the Criminal Code:

687. (1) Where an appeal is taken against sentence, the court of appeal shall, unless the sentence is one fixed by law, consider the fitness of the sentence appealed against, and may on such evidence, if any, as it thinks fit to require or to receive,

(a) vary the sentence within the limits prescribed by law for the offence of which the accused was convicted; or

(b) dismiss the appeal.

(2) A judgment of a court of appeal that varies the sentence of an accused who was convicted has the same force and effect as if it were a sentence passed by the trial court.
Where the Sentence is Served Before the Appellate Court Varies it

Courts may vary the sentence of the trial judge, increasing it, but stay the application of the sentence and direct that no warrant issue for the Accused’s arrest or committal. 
See for instance, R. v. Gowdy, 2016 ONCA 989 (CanLII).
Summary Conviction Proceedings—Leave to Appeal to the Court of Appeal

An applicant may seek leave to appeal his conviction to the Court of Appeal pursuant to s. 839 of the Criminal Code.

Leave to appeal pursuant to s. 839 should be granted sparingly. There is no single litmus test that can identify all cases in which leave should be granted. There are, however, two key variables – 
1.      The significance of the legal issues raised to the general administration of criminal justice, and

2.      The merits of the proposed grounds of appeal.

On the one hand, if the issues have significance to the administration of justice beyond the particular case, then leave may be granted even if the merits are not particularly strong, though the grounds must at least be arguable. On the other hand, where the merits appear very strong, leave to Appeal may be granted even if the issues have no general importance, especially if the convictions in issue are serious and the applicant is facing a significant deprivation of his or her liberty.

R. v. R.R., 2008 ONCA 497, 90 O.R. [3d] 564, at para 37. 
Unreasonable verdicts (jury)

When an appellant seeks an acquittal on the basis of an unreasonable verdict, an appellate court asks: is the verdict one that a properly instructed jury could reasonably have rendered?. If the answer is no, the verdict is unreasonable.
See R. v. Biniaris, [2000] 1 S.C.R. 381, at para. 36.

The reasonable verdict analysis has two counterbalancing components.  An appellate court must engage in a limited re-weighing of the evidence.  In doing so, the court looks at the evidence through the lens of judicial experience.  However, the court must also recognize the paramount and advantaged position of the jury as fact finder.  The appellate court acknowledges that advantage by deferring to the jury’s assessment of the evidence if the jury’s assessment, that is its verdict, is within the reasonableness range having regard to the totality of the evidence.  

The appeal court does not scour the record in search of explanations for, or gaps in, the evidence that are arguably inconsistent with the jury’s verdicts.  Instead, the appellate court accepts that the jury has performed its function and asks whether the jury’s ultimate assessment is a reasonable one.  The mere fact that the appeal court, or another reasonable jury, might have reached different verdicts is not determinative of the reasonableness of the verdicts actually reached by the jury.

See R. v. Romain, 2017 ONCA 519, at paras. 40-42.
Unreasonable verdict (judge alone)

While the test for unreasonable verdict is whether the verdict is one that a properly instructed jury acting judicially, could reasonably have rendered, the review for unreasonableness on appeal is different, however, and somewhat easier when the judgment under attack is that of a single judge, at least when reasons for judgment of some substance are provided.

As Arbour J. says in R. v. Biniaris, [2000] 1 S.C.R. 381 at para. 37:

In those cases, the reviewing appellate court may be able to identify a flaw in the evaluation of the evidence, or in the analysis, that will serve to explain the unreasonable conclusion reached, and justify the reversal. The court of appeal will therefore be justified to intervene and set aside a verdict as unreasonable when the reasons of the trial judge reveal that he or she was not alive to an applicable legal principle, or entered a verdict inconsistent with the factual conclusions reached. These discernable defects are themselves sometimes akin to a separate error of law, and therefore easily sustain the conclusion that the unreasonable verdict which rests upon them also raises a question of law.

For an example, see R. v. M.B., 2017 ONCA 653.

Voluntariness of a Statement

Deference is owed a trial judge’s determination of the voluntariness of a statement, provided that the correct test is applied and all relevant circumstances are considered.

R. v. Spencer, 2007 SCC 11, [2007] 1 S.C.R. 500, at para. 170;

R. v. Pearson, 2017 ONCA 389, at para 14.

Stuart O’Connell, O’Connell Law Group, www.leadersinlaw.ca