One of the knotty little problems that crops up in the lower courts is whether a police search for alcohol in a person's possession in a liquor ban area can properly extend to a search for drugs, even if the initial search had been carried out illegally. I was reminded of this on reading R v Nolet  SCC 24 (25 June 2010). This involved initial vehicle stoppage for transport regulation compliance, the discovery of a large amount of money, arrest for possession of proceeds of crime, a further search of the vehicle revealing a large quantity of cannabis, impounding of the vehicle and a later inventory search yielding evidence of transport licencing infringements.
What is of interest in the wider context is the treatment, by Binnie J delivering the judgment of the Supreme Court, of so-called mixed-purpose searches. One approach to this sort of problem is to argue that the regulatory search was really a sham and that the real purpose was to search for evidence of the more serious offending even though there were no grounds for such a search. At para 39 Binnie J rejects the predominant purpose inquiry and prefers a focus on whether the defendant's Charter rights have been breached.
Nolet also illustrates the proper approach to these problems which is to proceed by a step-by-step analysis of the facts.
As I began by mentioning liquor searches, I should say a bit more about them. Section 169 of the Local Government Act 2002 provides for police powers to search for liquor in the possession of a person in a liquor ban area. Important limitations on that search power are in s 170. The s 169 power does not contain a requirement that an officer must have reasonable grounds to believe that liquor will be found. Local bylaws, for example those enacted by Auckland City, do not restrict these searches to occasions where such reasonable grounds exist. But s 21 New Zealand Bill of Rights Act 1990 gives everyone the right to be secure against unreasonable search and seizure. On the Nolet approach, the question in any given case would be whether the particular search was a breach of s 21. The argument would be that lawful powers must be exercised reasonably.
If sufficient grounds for a liquor search existed, the search might be unlawful because of breach of s 170. For example, because of failure to give the person an opportunity to remove the liquor from the ban area. What would be the relevance of that illegality if the police had discovered drugs after completion of the search for liquor and after the illegality arose?
In deciding whether a search that yielded drugs was unreasonable, the grounds for the search would be assessed but by ignoring unlawfully obtained information. In the absence of any reason to believe that drugs would be found, the search that discovered them would be unreasonable. Whether evidence of the finding of the drugs would be admissible would then have to be determined by a balancing exercise (analogous to, but not the same as, that carried out in Nolet pursuant to Grant in relation to the evidence of licencing breach discovered during the final inventory search), pursuant to s 30 Evidence Act 2006. I would expect, in the light of case law, that if the drug offending was of such seriousness as to attract a starting point for sentencing of under four years' imprisonment, and if the improper search involved search of the defendant, a bag he carried, or the vehicle he was in, that the court would exclude the evidence.
But I may be wrong. Don't rely on my views.