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

180 MANITOBA LAW JOURNAL|VOLUME 36 ISSUE 1
operate. 172 Even in the hearsay context, where evidence can be admitted
pursuant to a principled approach that assesses whether the impugned
evidence has sufficient reliability and necessity, assessments which are
heavily imbued with considerations of probative value and prejudice, there
is room for this discretion to operate. 173
Second, its prevailing formulation – that Crown evidence may be
excluded where its prejudice outweighs its probative value – is broader
than that of the other discretions, save that which is contained within
certain statutory rules of admissibility. For example, the formulation in
Seaboyer, applying to defence evidence, requires that prejudice substantially
outweigh probative value before the discretion to exclude becomes
exercisable. The general exclusionary discretion read into most statutory
rules of admissibility applies only to those sparse 174 statutory rules, with
the result that its scope is more restricted in the sense that it will be
exercisable in far fewer situations (even where the standard is the same).
And, of course, some particular statutory discretions may have particular
restrictions or freedoms unique to them. 175
172
Having said this, it has at least three limits. First, it has no applicability to defence
evidence. Second, it has no applicability to statutory rules of evidence, though the
prevailing balancing exercise on which most statutory discretions are (or have been)
based is the same, namely a weighing of probative value against prejudice. Third, it
may not always be exercisable against illegally or improperly obtained evidence since
the “constitutionalized common law discretion” recognized in Harrer and the Charter’s
exclusionary rule contained in section 24(2) specifically deal with this.
173
Welsh, supra note 6 at para 34; Devine, supra note 128 at para 30; R v Khelawon, 2006
SCC 57, [2006] 2 SCR 787 at para 49.
174
I have found only five statutory sections in which such a discretion has been expressly
incorporated by the courts. That said, it seems likely that most, if not all, statutory
rules of admissibility must be read as including a judicial discretion to exclude in
order to remain constitutionally valid: see Section I and accompanying notes above.
175
For example, in Potvin, the Supreme Court held that the statutory discretion
incorporated into section 715 of the Criminal Code is only exercisable in rare
circumstances, based on a narrow weighing exercise. Having said that, the
aforementioned limitation only pertains to section 715 of the Criminal Code. Other
statutory sections (concerning admissibility of evidence at a criminal trial) in which a
judicial discretion to exclude has been incorporated are not similarly saddled. They
operate on the same standard as the general discretion from Seaboyer: where the
prejudice of a piece of evidence outweighs its probative value, it may be excluded.
What is more, one of the two circumstances in which the judicial discretion to
exclude contained in section 715 of the Criminal Code becomes exercisable (where