1. Arrest and Detention

Arrest and Detention Summary #

General points #

Section 9 of the Charter guarantees everyone a right “not to be arbitrarily detained or imprisoned.”

The Supreme Court in R v Le held that in order to be valid under section 9, a detention must be “authorized by law; the authorizing law itself must not be arbitrary; and, the manner in which the detention is carried out must be reasonable.”

A person is detained within the meaning of section 9 where police conduct would cause a reasonable person in the circumstances to conclude that he or she was not free to go and had to comply with a police direction or demand.

If not a person is detained or under arrest, police may question them and the person may refuse to cooperate. This includes questions pertaining to identity unless, in the context, there is a legal requirement to provide this. (Grant, Le)

Police have the power to carry out an ‘investigative detention’ where they have a reasonable suspicion implicating the person in an offence being investigated and where it is reasonably necessary on an objective view of the totality of the circumstances (Mann). An investigative detention triggers 10(a) and (b) of the Charter [more detail below].

Police also have the power to carry out a limited frisk search incident to investigative detention where they have a reasonable suspicion that safety is at risk [for more on this, see the “Search and Seizure” summary].

Police may arrest on grounds set out in section 495(1) and in certain other situations (under statute and common law: e.g., breach of the peace under s. 31 of the Code and at CL: Hayes v Thompson).

Police may carry out a limited search incident to arrest without requiring further grounds. A strip search upon arrest requires additional grounds, and a strip search at the scene of arrest requires grounds in addition to those [for more on this, see the “Search and Seizure” summary].

1. Arrest powers under the Criminal Code: #

a) Powers of police under s 495 #

Pursuant to section 495(1) of the Criminal Code, a PO may arrest a person where the officer has reasonable grounds to believe that an individual is subject to an arrest warrant, or has committed or is about to commit an indictable offence [which includes a hybrid offence], or if she finds a person committing any offence.1

Meaning of reasonable grounds

As explained in the ‘Note on Standards’ below, the phrase ‘reasonable grounds to believe’ in s 495(1) is read synonymously in the case law with ‘reasonable and probable grounds to believe.’ Under s 495(1), an officer must believe that a suspect has probably committed or is probably about to commit an indictable offence. Probable grounds requires “a reasonable belief that an individual is connected to the offence”; it exist when there is “an objective basis for the belief which is based on compelling and credible information” (Beaver).

The Supreme Court in Storrey held that an officer must hold the ‘reasonable belief’ in (what is now) section 495(1) subjectively and the belief must also be objectively reasonable.

The officer must “honestly believe that the suspect committed the offence” (Shepard), and the belief will be objectively reasonable where “[a] reasonable person, standing in the shoes of the police officer, would have believed that reasonable and probable grounds existed to make the arrest.” (Storrey)

The reasonable person here would share “the officer’s knowledge, experience and training” when assessing whether, in “the totality of the circumstances known to the officer at the time of the arrest,” there were reasonable grounds to arrest. (St Clair, ONCA)

When one officer directs another officer to make an arrest, only the directing officer need have reasonable and probable grounds. (Beaver, Debot)

Where an officer’s grounds for arrest are based on a mistake of law (i.e., assuming facts before her amount to something that is not an offence), the arrest is invalid however reasonable the mistake may have been. (Tim)

Whether an officer had reasonable grounds (or not) is a question of law, subject on appeal to the standard of correctness.2 (Shepherd)

b) Powers of citizens and property owners under s 494 #

Persons other than peace officers may arrest without a warrant anyone they find committing an indictable office, or anyone they have reasonable grounds to believe has committed a ‘criminal offence’ (summary or indictable) and is being freshly pursued by someone with lawful authority to arrest: s. 494. By contrast (to other civilians), property owners may arrest a person they find committing a ‘criminal offence’ (see s. 494(2) for further qualifications).

c) Other Code powers #

Breach of undertaking

The Code contains a host of other arrest powers relied upon less often than those in 495(1), including the power in s 495.1 to carry out an arrest without warrant on reasonable grounds to believe an accused has breached (or will) terms of a summons, appearance notice, undertaking or release order; and powers to arrest for ‘breach of the peace’ (ss 30 and 31).

Breach of the peace

Breach of the peace involves actions that cause or are likely to cause harm to persons or property. The Code authorizes detention or arrest for this, but does not make it an offence. Civilians may detain for breaches of peace they witness (s. 30); police for this but also at common law for those immediately imminent (s. 31 and Thompson v Hayes, BCCA 1985; Brown v Durham, OCA 1998).

Warrantless entry to effect arrest

Under section 529.3(1) of the Criminal Code, police may enter a dwelling house without a warrant in order to carry out an arrest where they have reasonable grounds to believe the person is present and the conditions are present to obtain a warrant under 529.1 (RPG) but due to exigent circumstances this is not practicable.

For the purposes of this section, exigent circs are defined 529.3(2) to require (a) reasonable grounds to suspect that it is necessary to prevent imminent danger of bodily harm or death, or (b) reasonable grounds to believe that entry is necessary to prevent against the imminent loss or destruction of evidence of an indictable offence.

Use of force

A PO or civilian may use as much force as is reasonably necessary to effect a lawful arrest, s 25(1).

d) General principle supporting release #

Section 493.1 compels police officers and judges to “give primary consideration to the release of the accused at the earliest reasonable opportunity and on the least onerous conditions that are appropriate in the circumstances”.

Police must also “give particular attention to the circumstances of (a) aboriginal accused; and (b) accused who belong to a vulnerable population that is overrepresented in the criminal justice system and that is disadvantaged in obtaining release under this Part” (493.2).

Public interest grounds

For a range of offences set out in section 495(2) [summary, hybrid, and indictable offences under s. 553], police must release a person immediately after “arrest” (or in lieu of carrying out a full arrest) unless detaining them further is necessary for any of the “public interest” reasons set out in s. 495(2) (ID, evidence, avoiding continuation/repetition of offence, or to ensure court attendance).

2. Investigative detention #

At common law, police have a power to detain a person briefly for investigative purposes.

Where a person is subject to an ‘investigative detention’, their rights under under sections 9 and 10(a) and (b) of the Charter right are engaged. (Mann, Grant)

Police are authorized to conduct an ‘investigative detention’ when they have

(a) a reasonable suspicion that the individual is implicated in the offence being investigated and

(b) where the detention is reasonably necessary on an objective view of the totality of the circumstances. (Mann)

On the first point: there must be a clear nexus, based in evidence, tying the particular person detained to the offence being investigated (“individualized suspicion”). Courts will assess whether an officer had a ‘reasonable’ suspicion by considering the reasonable person in the officer’s position. (Mann)

On the second point: factors to consider here include “the extent to which the interference with individual liberty is necessary to perform the officer’s duty [to investigate crime], the liberty interfered with, and the nature and extent of the interference.” (Mann)

As noted, an investigative detention triggers both 10(a) and 10(b). Police must inform the detainee, without delay, of the reason for the detention and their right to retain counsel. But police may briefly delay discharging their duties under 10(b) to carry out a safety search. (Grant, Suberu)

Investigative detention is distinct from what the Supreme Court has called “preliminary investigative questioning.” A person here is not detained and police are not obliged to advise them that they do not have to answer questions. (Suberu)


The Court in Clayton held that police may set up a blockade and detain for investigative purposes persons if (a) doing so still involves individualized suspicion (or a nexus tying detainees to the offence being investigated) and (b) where it is reasonably necessary to do so based on the totality of the circumstances, including:

i. the nature of the situation (including the seriousness of the offence);

ii. the information known to the police about the crime and/or the suspects; and

iii. whether the stop/detention (i.e. geographic and temporal scope) is reasonably tailored to the offence, and in balancing the risk to the public versus the liberty of citizens, the stop is no more intrusive than is “reasonably necessary.” (Clayton)

An investigative detention should be brief, but may be as broad (in time or space) as is “reasonably necessary in the totality of the circumstances,” so long as its purpose is restricted to investigating the involvement in crime of particular suspects. (Clayton)

3. Test for whether and when a ‘detention’ has occurred #

In Grant, the Supreme Court set out a test for deciding whether a “detention” for the purpose of sections 9 and 10 of the Charter has occurred. A person is “detained” where there is significant:

a. physical restraint, or

b. psychological compulsion.

-psychological compulsion is established where there is:

i. legal compulsion: where an officer makes a demand to comply pursuant to statute: eg, a roadside breath demand; or

ii. non-legal compulsion, which arises in circumstances where “police conduct would cause a reasonable person conclude that he or she was not free to go and had to comply with the police direction or demand.” [The test is purely objective.]

The Court in Grant held that whether the reasonable person subject to non-legal compulsion would conclude they were detained depends on the following criteria considered in their totality:

i. circumstances giving rise to the encounter as reasonably perceived by the individual [were they subject to general inquiries or singled out?];

ii. nature of the police conduct [language, duration, place, physical contact, presence of others, etc.];

iii. particular characteristics/circumstances of the individual [age, physical stature, sophistication, being a member of a racial minority].

The Supreme Court in Le held that under the 3rd part of this test, the reasonable person in the position of a racialized person is presumed to be aware of the “broader historical and social context of race relations between the police and various racial groups and individuals in society.”

In the broader ‘racialized context’ of a police encounter with a visible minority, it is irrelevant whether the police involved engaged in racial profiling when assessing whether the reasonable person would have experienced significant compulsion. (Le)

In a given set of circumstances, a racialized accused might be more likely than a white person to infer that they have no choice but to comply with a police direction or demand – and this inference may be reasonable in the circumstances, based on the weight of recent social science evidence. (Le)

The detention analysis in Grant and Le is principally objective in nature. (Evidence of what the police or the accused personally perceived is important, but not determinative of whether the factors pointing to psychological detention were, in their totality, significant.)

The Supreme Court in Lafrance (2022) held that “no single consideration, including a police statement to an individual that he or she is ‘not detained’ or otherwise under any obligation to cooperate or may leave, is determinative of whether a detention has occurred.” This is only one consideration among others “for which a court should account in deciding whether a reasonable person in the shoes of the accused would feel obliged to cooperate.”

Note on standards #

The common law makes the following distinctions on standards in criminal law:

  • suspicion’ would be something merely possible, even if its probability is low;

  • a ‘reasonable suspicion’ would be a reasonable possibility, or something not quite probable but more than hypothetical (SCC: Kang-Brown, Chehil);

  • reasonable grounds to believe’ and ‘reasonable belief’ have been held by the SCC in Debot and Baron to be synonymous with ‘reasonable and probable grounds,’ and each is a way of saying there is a reasonable probability of something3; and

  • balance of probability’ means greater likelihood or ‘more likely than not’.

    Justice Jamal, for majority of the SCC in Beaver (2022), held that:

    Reasonable suspicion requires a reasonable possibility of crime, while reasonable and probable grounds requires a reasonable probability of crime […] At the same time, police do not require a prima facie case for conviction before making an arrest […] Nor do the police need to establish that the offence was committed on a balance of probabilities. Instead, the reasonable and probable grounds standard requires “a reasonable belief that an individual is connected to the offence” […]. A reasonable belief exists when “there is an objective basis for the belief which is based on compelling and credible information” […]. The police are also not required to undertake further investigation to seek exculpatory facts or to rule out possible innocent explanations for the events before making an arrest. (Citations omitted)

  1. Section 34(1)(a) of the Interpretation Act defines an ‘indictable offence’ to include hybrid offences; see also R v Dudley, SCC 2009, applying this provision to the meaning of ‘indictable offence’ in the Criminal Code. ↩︎

  2. By contrast, a trial judge’s findings of fact with respect to the “existence of reasonable and probable grounds” are reviewable “only for palpable and overriding error”: Beaver (SCC 2022). ↩︎

  3. Some authorities had suggested the SCC decisions in Debot, Baron, and Storrey support the proposition that ‘reasonable and probable grounds’ means balance of probabilities or ‘more likely than not’, despite the Court not having stated this explicitly in those cases. The majority in R v Beaver, 2022 SCC 54 has now settled this by holding that RPG does not mean ‘more likely than not,’ which suggests that it may involve a probability less than that (but still a reasonable probability). The precise level of probability for RPG remains unclear. For an example of a recent court decision outlining the state of this uncertainty, see paras 145-157 in Can v Calgary (Police Service), 2014 ABCA 322, which should now be read in light of R v Beaver. ↩︎

© Robert Diab 2023