The RCMP began investigating the accused, Walter Tessling, after receiving tips from two informants that he may be producing and/or trafficking in marijuana. In the course of its investigation, the RCMP monitored Mr. Tessling’s home using an aircraft equipped with Forward Looking Infra-Red (“FLIR”) technology.
The FLIR scan detected an unusual amount of heat emanating from Mr. Tessling’s home, which in turn allowed the RCMP to obtain a search warrant. Upon executing the warrant, a large quantity of marijuana and several firearms were discovered.
Mr. Tessling argued at trial that the RCMP flyover constituted an unreasonable search, contrary to his rights under Section 8 of the Charter. The trial judge rejected this argument, but was overruled by the Court of Appeal, which excluded the Crown’s evidence and entered an acquittal.
On further appeal, the Supreme Court of Canada concluded that the type of information obtained by the FLIR scan did not engage Mr. Tessling’s reasonable expectation of privacy.
Thus, when one considers the “totality of the circumstances”, the use of FLIR technology did not intrude on the reasonable sphere of privacy of the accused. Patterns of heat distribution on the external surfaces of a house are not a type of information in which, objectively speaking, the accused had a reasonable expectation of privacy. The heat distribution information offered no insight into his private life and its disclosure scarcely affected his “dignity, integrity and autonomy”.
Although not helpful to Mr. Tessling, this ruling leaves open the possibility that future advances in technology might render such high-tech surveillance tactics contrary to the reasonable expectation of privacy enshrined in Section 8:
 I agree with Abella J.A. that the spectre of the state placing our homes under technological surveillance raises extremely serious concerns. Where we differ, perhaps, is that in my view such technology must be evaluated according to its present capability. Whatever evolution occurs in future will have to be dealt with by the courts step by step. Concerns should be addressed as they truly arise. FLIR technology at this stage of its development is both non-intrusive in its operations and mundane in the data it is capable of producing. It is clear, to repeat, that at present no warrant could ever properly be granted solely on the basis of a FLIR image.
Decided by the Supreme Court of Canada on October 29, 2004.
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