Is infrared surveillance "search"?

Infrared surveillance may reveal patterns of heat emerging from a building. That in turn, when added to other information, may provide reasonable grounds for the issuing of a search warrant. Cannabis cultivation indoors can be discovered in this way. That happened in R v Tessling 2004 SCC 67 (29 October 2004). The Supreme Court of Canada held that, the present state of technology being insufficient to reveal exactly what was going on in the respondent’s house, he had no reasonable expectation of privacy in the circumstances of this case. Accordingly, there was no breach of his right to be free from unreasonable search.

The United States Supreme Court had held differently in Kylio v US 533 US 27 (2001). There, the majority held that the Government conducts a search of a home when it uses a device that is not in general public use to explore details of the home that would have previously been unknowable without physical intrusion. Further, a such a search was presumptively unreasonable without a warrant.

The point has not yet been decided in New Zealand, but some similar situations have been considered. (See Mathias, Misuse of Drugs, para 1405.) In R v Gardiner 30/6/97, Chisholm J, HC Christchurch T45/97 it was held that camera surveillance from outside premises, where views of the interior of the house were obtained, amounted to a search which, in the circumstances of this borderline case, was not unreasonable. It was noted that the police had good grounds to believe serious drug offending was occurring on the premises. Where police conduct was reasonable, it was not necessary to determine whether video surveillance of the back of a residential property by a camera outside the premises amounted to a search: R v Fraser [1997] 2 NZLR 442, (1997) 15 CRNZ 44 (CA). In that case the area filmed was readily visible to passers-by. Aerial surveillance from an aircraft flying at approximately 500 feet over farmland was not, on the facts, unreasonable in R v Peita (1999) 17 CRNZ 407 (CA), but the Court was careful to point out (at para 13) that "each case must be considered on its own facts, bearing in mind the privacy based nature of the right and its reasonable qualification by the public interest in crime detection".