Misapprehension of evidence

R. v. Mahmood, 2011 ONCA 693, released today, gives useful guidance on misapprehension of evidence at trial. Not every failure at trial renders a decision subject to appeal. Misapprehension of evidence, when advanced as a ground to impeach a final verdict, must be material, not merely peripheral to the reasoning of the trial judge, in other words, the reasons must play an essential part in the reasoning process resulting in a conviction:


The Governing Principles

[46]         A misapprehension of evidence may involve a failure to take into account an item or items of evidence relevant to a material issue, or it may have to do with a mistake about the substance of the evidence. A misapprehension of evidence may also reflect a failure to give proper effect to evidence: R. v. Morrissey (1995), 22 O.R. (3d) 514 (C.A.), at p. 538.

[47]         Every misapprehension of evidence does not render a trial unfair or result in a miscarriage of justice. An appellate court must determine the nature and extent of an alleged misapprehension and its significance to the decision under review, whether a determination of admissibility or a final conclusion about guilt. Rulings on admissibility and final verdicts must be based exclusively on evidence adduced at trial: Morrissey, at p. 541.

[48]         The standard applied where an appellant advances misapprehension of evidence as a ground of appeal is stringent. The misapprehension of evidence, when advanced as a ground to impeach a final verdict, must be material, not merely peripheral to the reasoning of the trial judge, in other words, the reasons must play an essential part in the reasoning process resulting in a conviction, not just in the narrative of the judgment: R. v. Lohrer, 2004 SCC 80, [2004] 3 S.C.R. 732, at para. 2.