Under the first line of inquiry which assesses the seriousness of the Charter-infringing state conduct, extenuating
circumstances, such as the need to prevent the disappearance of
evidence and good faith may attenuate the seriousness of the
breach. But care must be taken to ensure that ignorance of
Charter standards is neither rewarded nor encouraged and that
negligence or wilful blindness does not become a proxy for good
faith. Evidence that the Charter-infringing state conduct was
part of a pattern of abuse tends to support exclusion: Grant,
at para. 75.
 The second line of inquiry, which focuses on the seriousness of the impact of the Charter breach on the Charter-
protected interests of the accused evokes an evaluation of the
extent to which the breach actually undermined the interests
protected by the right infringed. We look to the interests
engaged by the infringed right and examine the degree to which
the violation impacted on those interests: Grant, at paras. 76-77.
The more serious the impact on the accused’s Charter-protected
interests, the greater the risk that admission of the evidence
may signal to the public the Charter rights, high sounding as
they may be, are of little avail to the citizen, thus breeding public cynicism and bringing the administration of justice into
disrepute: Grant, at para. 76.
 Under the third inquiry, the fact that the constitutionally tainted evidence may facilitate the discovery of the truth
and the adjudication of the case on the merits must be weighed
against the factors favouring exclusion so that the interests of
truth may be balanced against the integrity of the justice system: Grant, at para. 82: Mann, at para. 57.
 The inquiries directed by Grant require both fact-finding
and the weighing of various, often competing interests:
McGuffie, at para. 64. No overarching rule governs how the balance is to be struck: Grant, at para. 86. On appellate review, the
decision to admit or exclude evidence under s. 24(2) [of the
Charter] is entitled to deference, absent an error in principle, a palpable and overriding error of fact or a determination that is
unreasonable: McGuffie, at para. 64.
The principles applied
 As I will explain, the trial judge erred in his s. 24(2)
analysis. Those errors require appellate intervention and a
reappraisal of the admissibility of the evidence. That reappraisal
leads to an exclusion of the evidence.
 At the front end of any s. 24(2) analysis is a determination of the fact, nature and extent of Charter infringement. The