MLJ Volume 36-1.pdf - Robson Hall Faculty of Law

The Trial Judge's Four Discretions 169
discretion to exclude the evidence. Consequently, where he or she has a
reasonable basis for concluding that the evidence’s prejudicial effect
outweighs its probative value, the trial judge may exclude the evidence
regardless of any submissions, joint or otherwise, from counsel that dictate
the opposite outcome.
Needless to say, depending on the particular circumstances of any
case, a variety of factors that serve to inform the level of prejudicial effect
of the evidence will present themselves. “The relative weight to be assigned
to factors requires an ad hoc judgment and is not a process that can be
captured by a bright line capable of yielding a single correct result.” 127
Once the assessments of prejudice and probative value are complete, a
balancing of one against the other occurs. Where prejudice is found to
outweigh probative value, the evidence may be excluded. This exercise
must be completed by a trial judge before any application of the
exclusionary discretion, though he or she may not need to refer explicitly
to this balancing in their reasons for decision. 128 The exclusionary
discretion, while integral to ensuring the fairness of the trial process,
should not be viewed as “a blanket discretion for judges to repudiate
conduct on the part of authorities regarded as distasteful or
inappropriate.” 129 In other words, where the probative value of Crown
evidence is found to outweigh its prejudicial effect, even by the slightest of
margins, the evidence, no matter how objectionable, must be received. 130
127
R v Pilon, 2009 ONCA 248 at para 54, 243 CCC (3d) 109. The same can no doubt be
said of the statutory discretions that exist within statutory rules of admissibility.
128
R v Devine, 2008 SCC 36 at para 30, [2008] 2 SCR 283 [Devine].
129
Rothman, supra note 36 at 696, per Lamer J. While this statement was made in the
context of a different exclusionary rule, a “pure discretion” to exclude (see Section I
and note 40 above) contained within then section 178.16 of the Criminal Code (supra
note 23), it is equally applicable to the trial judge’s exclusionary discretion regarding
Crown evidence at common law established in Seaboyer.
130
A properly crafted jury instruction cautioning the jury about the impermissible use of
the evidence can sometimes provide a piece of evidence, which might not otherwise
have enough probative value to exceed prejudicial effect, with sufficient probative
value to make it receivable. This is because a proper jury direction can reduce or
remove prejudicial effect, such that prejudicial effect no longer exceeds probative
value: See generally Paciocco & Stuesser, supra note 1 at 44.