The unreasoned consequences of unreasonable search

Lawful powers must be exercised reasonably, and it must be reasonable to have resort to those powers. An illustration of unreasonable resort to lawful powers is R v Aucoin, 2012 SCC 66 (30 November 2012).

Upon apprehending the defendant for traffic offences involving licensing and alcohol the officer decided to detain him in the police vehicle because he was concerned that the defendant might run away. A pat-down search of the defendant was carried out prior to this detention. Cocaine was found in a quantity that subsequently supported the defendant's conviction for possession of cocaine for trafficking. There were alternative and reasonably available ways in which the officer could have addressed his concern about the defendant running away.

All members of the Court held that it was on the particular facts unreasonable for the officer to exercise his power to carry out the search and detention, but only a majority held that the evidence was admissible.

On the facts, backup was close at hand so there was no reasonable necessity to detain the defendant in the police vehicle. There was disagreement over the extent of the balancing required to determine reasonableness: the majority appear to accept that regardless of the seriousness of the offence for which the defendant was initially stopped, if detention was reasonably necessary to prevent flight there was no need to take account of the seriousness of the offence: Moldaver J for the majority at [43], disagreeing with LeBel J for the minority at [86].
It is useful when majority judgments directly address points made in minority judgments. Unfortunately such cross-referencing did not occur on the critical issue in the case: the admissibility of the improperly obtained evidence.

The majority addressed briefly the decision process required by R v Grant, 2009 SCC 32 (CanLII), 2009 SCC 32, [2009] 2 S.C.R. 353 (discussed by me here and here and here and here). It seems that the critical point of difference from the minority assessment is that the majority accepted that the officer was not simply applying his standard procedure for more serious offences when he detained the defendant [45], [48]. The minority view of the evidence contrasted sharply, referring to the constable's evidence about his standard practice in relation to detained motorists [101] and this, for the minority, was evidence of a pattern of abuse.

How do appellate judges arrive at such different assessments of the evidence?

All judges agreed that the defendant's expectation of privacy in relation to the contents of his pockets was high, but the minority mentioned too the aggravating feature of questioning the defendant about the contents of his pockets which introduced the right to be protected against self-incrimination [104]. This did not feature in the majority's analysis. Why not?

The majority said that the impact on the defendant's privacy rights was significant, but no more so than society's interest in having the case tried on the merits [51]. There is no explanation of how that evaluation was reached. Neither is there reasoned support in the minority judgment for its opposite conclusion on admissibility. What was the likely starting point for sentence for the cocaine offence (the defendant received a sentence of two years' imprisonment)? Probably it was not in the medium-to-high range, so how was society's interest measured? What relevant decisions supported the conclusion? What do other cases say about the defendant's privacy interests as against the seriousness of the detected offending?

Unpredictability comes from the vagaries of judicial assessment of the evidence and of the relative strengths of rights.