Blue Line

Reasonable suspicion suffices for sniff search

Canada's highest court has upheld the reasonable suspicion standard as the threshold for using a dog to sniff out drugs in airline luggage.

In R. v. Chehil, 2013 SCC 49 a drug enforcement team at the Halifax airport analyzed the electronic passenger list of an overnight WestJet flight from Vancouver. Chehil was the last passenger to purchase a ticket, paid cash and checked one bag.

Drug couriers often travel alone on overnight flights, buy a last minute, walk-up ticket in cash and check a single bag so they removed his luggage, along with nine other bags, and had them searched by a drug-sniffing dog. It indicated a positive hit on Chehil's luggage, which police returned to the conveyor belt.

October 8, 2013  By Mike Novakowski

Canada’s highest court has upheld the reasonable suspicion standard as the threshold for using a dog to sniff out drugs in airline luggage.

In R. v. Chehil, 2013 SCC 49 a drug enforcement team at the Halifax airport analyzed the electronic passenger list of an overnight WestJet flight from Vancouver. Chehil was the last passenger to purchase a ticket, paid cash and checked one bag.

Drug couriers often travel alone on overnight flights, buy a last minute, walk-up ticket in cash and check a single bag so they removed his luggage, along with nine other bags, and had them searched by a drug-sniffing dog. It indicated a positive hit on Chehil’s luggage, which police returned to the conveyor belt.

Chehil was arrested for drug possession when he collected the locked bag and it was forced open and manually searched. Three kilograms of cocaine was found. He was then re-arrested for possession for the purpose of trafficking and charged.


A Supreme Court of Nova Scotia judge ruled that police did not have a reasonable suspicion to deploy the dog near Chehil’s checked baggage, in which he had a reasonable expectation of privacy. He found that only the cash ticket purchase, perhaps at the last minute, could be viewed as suspicious. The remainder of the factors relied upon were open to several neutral explanations. In his view, police failed to conduct further investigation or consider exculpatory explanations for the other factors.

Since there were other potentially innocent explanations for the individual factors that could have been dealt with through further investigation, absent such investigation there could be no reasonable suspicion of involvement in drug crimes. Police were, at best, operating on intuition or an educated guess, the judge held.

The unauthorized sniff search was therefore unreasonable under s. 8 of the Charter and the evidence was excluded under s. 24(2). Chehil was acquitted.

The Crown appealed to Nova Scotia’s top court, which found the trial judge erred by considering each factor used by police in isolation. Rather than finding potential innocent explanations for each, the proper test was to determine whether all of the circumstances, looked at together, provided a reasonable suspicion. Whether additional steps could have been taken to buttress the grounds was irrelevant; police need only demonstrate they have done enough to establish reasonable suspicion.

The appeal court concluded police had sufficient reasonable suspicion to use the dog. The positive indication gave them reasonable grounds to believe the accused possessed illegal drugs. His arrest was lawful and the suitcase search reasonable. There were no Charter breaches. It ordered a new trial.

Chehil then appealed to the Supreme Court of Canada, arguing that the way police applied the reasonable suspicion standard would authorize generalized searches of a very large number of travellers. It was submitted that the mechanical application of profile characteristics would capture a high percentage of innocent people or racially marginalized groups.

He suggested police should have to conduct further investigation of individual factors that were neutral, innocuous and capable of innocent explanation, thus contending that they failed to satisfy the reasonable suspicion standard.

Reasonable suspicion

The high court unanimously found there was no need to revise the reasonable suspicion standard, holding it was robust, determined on a totality of the circumstances, based on objectively discernible facts and subject to independent and rigorous judicial scrutiny. In the court’s view, the standard prevents the indiscriminate and discriminatory exercise of police powers.

“The reasonable suspicion standard requires that the entirety of the circumstances, inculpatory and exculpatory, be assessed to determine whether there are objective ascertainable grounds to suspect that an individual is involved in criminal behaviour,” said Justice Karakatsanis. “It does not require the police to investigate to rule out exculpatory circumstances.”

As a result of this case, the following legal principles were recognized:

  • Using a dog trained to detect certain kinds of illegal drugs through smell is a search that does not require prior judicial authorization.
  • The common-law authorizes the deployment of a drug-sniffing dog.
  • Sniff searches are minimally intrusive, narrowly targeted and highly accurate.
  • To deploy a sniffer dog police must have a reasonable suspicion based on objective, ascertainable facts that evidence of an offence will be discovered.
  • The Crown bears the burden of showing that the objective facts rise to the level of reasonable suspicion, such that a reasonable person, standing in the officer’s shoes, would hold a reasonable suspicion of criminal activity.
  • The constellation of facts must be based in the evidence, tied to the individual and capable of supporting a logical inference of criminal behaviour. They must be assessed at the time of the search, not after. If the link between the constellation and criminality cannot be established by way of a logical inference, the Crown must lead evidence (empirical, statistical or based upon the investigating officer’s training and experience) to connect the circumstances to criminality.

An officer’s training and experience may provide an objective experiential, as opposed to empirical, basis for grounding reasonable suspicion. However, this is not to say that hunches or intuition grounded in an officer’s experience will suffice, or that deference is owed to a police officer’s view of the circumstances based on her training or experience in the field: see Payette, at para. 25. A police officer’s educated guess must not supplant the rigorous and independent scrutiny demanded by the reasonable suspicion standard.

Evidence as to the specific nature and extent of such experience and training is required so that the court may make an objective assessment of the probative link between the constellation of factors relied on by the police and criminality. The more general the constellation relied on by the police, the more there will be a need for specific evidence regarding police experience and training.

To the extent that specific evidence of the investigating officer’s experience and training supports the link the Crown asks the court to draw, the more compelling that link will be (para. 47).

  • The requirement for objective and ascertainable facts permits an independent, after-the-fact review by the court and protects against arbitrary state action.
  • Police must point to particularized conduct or evidence of criminal activity. However, it need not itself consist of unlawful behaviour or a specific known criminal act.
  • Reasonable suspicion (aka. reasonable grounds to suspect) addresses the possibility of uncovering criminality and is a lower and less demanding standard than reasonable probability (aka. reasonable and probable grounds to believe, reasonable grounds to believe), which addresses the probability of uncovering criminality).
  • Since reasonable suspicion deals with possibilities, innocent people may in some cases be reasonably suspected of a crime.
  • 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. A police officer’s grounds for reasonable suspicion cannot be assessed in isolation.”
  • “Exculpatory, neutral, or equivocal information cannot be disregarded when assessing a constellation of factors. The totality of the circumstances, including favourable and unfavourable factors, must be weighed in the course of arriving at any conclusion regarding reasonable suspicion.”
  • Some factors, on their own, will be insufficient to support a reasonable suspicion, but can nonetheless be used as one part of a constellation of factors. “While some factors, such as travelling under a false name or flight from the police, may give rise to reasonable suspicion on their own, other elements of a constellation will not support reasonable suspicion, except in combination with other factors. Generally, characteristics that apply broadly to innocent people are insufficient, as they are markers only of generalized suspicion. The same is true of factors that may ‘go both ways,’ such as an individual’s making or failing to make eye contact.”
  • Since the reasonable suspicion standard addresses the possibility of uncovering criminality, it need not be the only inference that can be drawn from a particular constellation of factors. Factors that give rise to a reasonable suspicion may also support completely innocent explanations.
  • The police obligation to take all factors into account does not impose a duty to investigate further to seek out alternative or possible innocent explanations for constellations of factors giving rise to reasonable suspicion.
  • Reasonable suspicion does not descend to the level of a “generalized suspicion” – a suspicion that attaches to a particular activity or location rather than a specific person. “A constellation of factors will not be sufficient to ground reasonable suspicion where it amounts merely to a ‘generalized’ suspicion because it ‘would include such a number of presumably innocent persons as to approach a subjectively administered, random basis’ for a search.”

Karakatsanis concluded:

In sum, when single-profile narcotic dogs are deployed on the basis of reasonable suspicion, the police intrusion must be connected to factors indicating a drug-related offence. Reasonable suspicion does not, however, require the police to point to a specific ongoing crime, nor does it entail the identification of the precise illegal substance being searched for. The reasonable suspicion held by the police need only be linked to the possession, traffic or production of drugs or other drug-related contraband (para. 37).


The particular circumstances of each case determines whether reasonable suspicion has been met. As for drug courier profiles, the court cautioned about using profile characteristics.

In my view, it is unhelpful to speak of profiling as generating reasonable suspicion. The term itself suggests an assessment based on stereotyping and discriminatory factors, which have no place in the reasonable suspicion analysis. Rather, the analysis must remain focused on one central question: Is the totality of the circumstances, including the specific characteristics of the suspect, the contextual factors and the offence suspected, sufficient to reach the threshold of reasonable suspicion?

The application of the reasonable suspicion standard cannot be mechanical and formulaic. It must be sensitive to the particular circumstances of each case. Characteristics identified by a police profile can be considered when evaluating reasonable suspicion; however, profile characteristics are not a substitute for objective facts that raise a reasonable suspicion of criminal activity. Profile characteristics must be approached with caution precisely because they risk undermining a careful individualized assessment of the totality of the circumstances.

In this case, the profiling alleged consisted of a set of factors that the officers had been taught to look for and had learned through experience to look for in order to detect drug couriers. Whether or not these factors give rise to reasonable suspicion will depend upon a police officer’s reasons for relying on specific factors, the evidence connecting these factors to criminal activity and the entirety of the circumstances of the case (paras. 39-41).

Reasonable suspicion

The police relied collectively, based on their training and experience with prior investigations, upon nine factors in their decision to deploy the drug sniffing dog:

  1. The one-way ticket
  2. The flight originated in Vancouver
  3. The accused travelled alone
  4. The cash purchase
  5. The ticket was the last purchased
  6. The accused checked one piece of luggage
  7. The flight was overnight
  8. The flight was mid-to late-week
  9. Drug couriers prefer less expensive airlines, such as WestJet. In her cross-examination, Cst. Ruby gave evidence that most people meeting this constellation had proved to be drug couriers.

The Supreme Court agreed that the trial judge erred by assessing the factors individually, rather than in their entirety. When viewed in their totality, police had a reasonable suspicion that they would discover evidence of a drug-related crime in Chehil’s luggage and a sniff search was justified. It was reasonable and the positive indication by the dog raised the reasonable suspicion to reasonable and probable grounds for arrest.

Chehil appeal was dismissed and the order for a new trial upheld.

Editor’s note: The court also spoke to the dog’s reliability and how it factored into the reasonableness of the search.

Print this page


Stories continue below