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Standard of Review

The trial judge’s factual findings are entitled to deference. Whether the factual findings of the trial judge amount at law to reasonable and probable grounds is a question of law and is reviewed on a standard of correctness: R v Dhillion, 2016 ONCA 308 at para 22

General Principles on Arrest


An arresting officer must subjectively have reasonable and probable grounds on which to base the arrest. Further, those grounds must be objectively justifiable to a reasonable person placed in the position of the officer: Dhillion at para 24

The standard is met at the point where credibly-based probability replaces suspicion: Dhillion, at para 25

Reasonable grounds can be based on a reasonable belief that certain facts exist even if it turns out that the belief is mistaken: R v Robinson, 2016 ONCA 402 at para 40. But, for example, see R v Brown, 2012 ONCA 225, in which two officers with the same information arrived at different conclusions as to the existence of reasonable grounds  

In determining whether the arresting officer had reasonable and probable grounds to arrest based on his own observations, it is irrelevant that other officers also made those observations, if those observations did not factor into the arresting officer's decision to arrest: R v Gonzales, 2017 ONCA at para 543 at para 106


An officer cannot rely upon an accused's refusal to answer questions as a factor supporting reasonable and probable grounds to arrest, as this "extracts a price for the exercise of a constitutional right:" Gonzales at para 105

When considering the objective reasonableness of the subjective grounds for arrest, a court must look to the totality of the circumstances, and it is not appropriate to consider each fact in isolation: R v Labelle, 2016 ONCA 110 at para 10

Where confidential informant information is the basis of grounds to arrest, the Debot factors apply. The court must weigh whether the informant was credible, whether the information predicting the commission of a criminal offence was compelling, and whether the information was corroborated by police investigation. The totality of the circumstances must meet the standard of reasonableness: Dhillion at para 30

For  "a non-exhaustive legal backdrop to review of the exercise of police arrest powers" by Justice Hill, see R v Cunsolo, [2008] OJ No 3754 (Sup Ct Jus) at para 68; see also R v Censoni, [2001] OJ No 5189 (Sup Ct Jus) at paras 30-40

For general principles on the use of confidential informants, see here



General Principles on Detention


The police may detain a person for investigative purposes if they have reasonable grounds to suspect that the person is connected to particular criminal activity and that such a detention is reasonably necessary in the circumstances: R v Darteh, 2016 ONCA 141 at para 4; R v McGuffie, 2016 ONCA 365 at para 35


The standard “reasonable grounds to suspect” requires that the police have a “reasonable suspicion” or a suspicion that is grounded in objectively discernible facts, which could then be subjected to independent judicial scrutiny: R v Darteh, 2016 ONCA 141 at para 4


Reasonable suspicion may be grounded in a constellation of factors, even if any one of those factors on its own would not have been sufficient: R v Darteh, 2016 ONCA 141 at para 7


A standard of reasonable suspicion addresses the possibility of uncovering criminality, not a probability of doing so as is the case for a reasonable belief: R v Nero, 2016 ONCA 160 at para 73

The duration and nature of a detention justified as an investigative detention must be tailored to the investigative purpose of the detention and the circumstances in which the detention occurs.   The police cannot use investigative detention as an excuse for holding suspects while the police search for evidence that might justify the arrest of the suspect.  Nor does investigative detention mean that the police can detain suspects indefinitely while they carry out their investigation: v McGuffie, 2016 ONCA 365 at paras 38-39



Detention versus Arrest

"[A]n investigative detention is not the same thing as an arrest and could not be allowed to become “a de facto arrest”.  The significant interference with individual liberty occasioned by an arrest is justified because the police have reasonable and probable grounds to believe that the arrested person has committed an offence.  Investigative detention does not require the same strong connection between the detained individual and the offence being investigated.  The detention contemplated by an investigative detention cannot interfere with individual liberty to the extent contemplated by a full arrest," R v McGuffie, 2016 ONCA 365 at para 37

Motor Vehicle Detentions


 A roadside stop of a vehicle for a provincial regulatory offence under statutes like theHTA (e.g. speeding) is a detention: R v Harflett, 2016 ONCA 248 at para 18

Where the police conduct a valid HTA stop and thereafter legitimately form reasonable and probable grounds to arrest and search a vehicle, the fact that the police had a dual HTA/criminal purpose at the very outset of the stop does not taint the lawfulness of the initial stop and detention: R v Johnson, 2016 ONCA 31 at para 9 



Border Detentions


Routine border searches do not result in a detention and therefore do not give rise to any right to counsel or the right to remain silent: R v. Jackman, 2016 ONCA 121 at para 33; R v Sinclair, 2017 ONCA 287 at para 6


Where, following a routine sniffer dog search at the border, a sniffer dog alert arises, this alert, standing alone, does not necessarily give rise to such a particularized level of suspicion that the accused's case ceases to be routine: R v. Jackman, 2016 ONCA 121 at para 33; Sinclair at para 7 




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