A majority judgment from the Supreme Court of Canada in a "sniffer dog" case provided the following comments regarding "reasonable suspicion" :
Reasonable suspicion derives its rigour from the requirement that it be based on objectively discernible facts, which can then be subjected to independent judicial scrutiny. This scrutiny is exacting, and must account for the totality of the circumstances. Thus, while reasonable grounds to suspect and reasonable and probable grounds to believe are similar in that they both must be grounded in objective facts, reasonable suspicion is a lower standard, as it engages the reasonable possibility, rather than probability, of crime. As a result, when applying the reasonable suspicion standard, reviewing judges must be cautious not to conflate it with the more demanding reasonable and probable grounds standard. Reasonable suspicion must be assessed against the totality of the circumstances. The inquiry must consider the constellation of objectively discernible facts that are said to give the investigating officer reasonable cause to suspect that an individual is involved in the type of criminal activity under investigation. This inquiry must be fact-based, flexible, and grounded in common sense and practical, everyday experience. R. v. Chehil, 2013 SCC 49