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

The Trial Judge's Four Discretions 161
since that case its ambit has grown substantially. 76 In Wray, the majority
decision of the Supreme Court, per Martland J, held that a trial judge has
the discretion to exclude legally admissible evidence that would operate
unfairly, arising from their duty to ensure the accused receives a fair trial. 77
A trial judge exercising that discretion is limited to ensuring the trial itself
is fair. In short, “a judge cannot look beyond the trial itself in exercising
this discretion.” 78 In other words, a trial judge has no jurisdiction to
exercise this discretion to exclude evidence for reason only that it was
obtained in an improper manner, since this arose during pre-trial
procedures. 79
A. The Wray Exclusionary Discretion
In Wray, prejudice was defined for the purpose of exclusion as
evidence that could operate unfairly and unjustly toward the accused, as
opposed to merely unfortunately. 80 The Supreme Court, obviously
wanting to restrict the scope of this discretion, purportedly to “preserve
the integrity of the rules of evidence,” 81 held that in order for a judge to
exercise his or her exclusionary discretion the evidence in question had to
be gravely prejudicial, of tenuous admissibility, and of trifling probative
note 1 at 37; Corbett, supra note 2 at 742. See also McWilliams et al, supra note 11 at 5-
2.
76
McWilliams et al, supra note 11 at 5-1– 5-2. The authors correctly attribute the growth
in the scope of the discretion to the seminal decision in Seaboyer, supra note 56. For
further comment: see Sopinka et al, supra note 5 at 31; Corbett, supra note 2 at 739,
per La Forest J (dissenting).
77
Wray, supra note 16 at 293.
78
AF Sheppard, “Restricting the Discretion to Exclude Admissible Evidence” (1971) 14
Crim LQ 334 at 336.
79
Ibid. Under existing law, there is an appreciation that improperly obtained evidence
can lead toward an unfair trial, requiring the trial judge to exercise his residual
exclusionary discretion to prevent such an occurrence. Unlike past practice, pre-trial
procedures and the trial itself are no longer treated as separate water-tight
compartments in relation to decisions whether to exercise an exclusionary discretion
based on the anticipation of an unfair trial.
80
Wray, supra note 16 at 293-295. See also Corbett, supra note 2 at 722, per La Forest J
(dissenting).
81
David M Paciocco, “The Proposed Canada Evidence Act and the “Wray Formula”:
Perpetuating an Inadequate Discretion” (1983) 29 McGill LJ 141 at 143 [Paciocco,
“Wray Formula”].