Detention in Ontario: Grounds, Rights, and Excluding Evidence

PUBLISHED ON October 10, 2025

Most people never interact with the criminal justice system until something unexpected happens: a traffic stop, a street encounter with police, or being questioned during an investigation. People may feel like they were arrested, only to learn later that they were technically detained. In Ontario, the difference between detention and arrest is not just academic—it defines the scope of a police officer’s power. Like arrests, a detention must be lawful. The rights afforded to an individual upon being detained must be exercised. Unlawful detentions and breaches of an individual’s rights upon being detained can result in extraordinary remedies, including the exclusion of evidence at trial.

What is written below provides a brief and general explanation of the law surrounding police arrests and detentions. This is not legal advice for you or for any particular case. Should you require legal advice, you should consult with an experienced criminal defence lawyer.

1.  What is a detention

A detention occurs when police meaningfully constrain a person’s liberty. This can be physical (being held, blocked, or restricted) or psychological (feeling obligated to comply because of police conduct). In the leading case of R. v. Grant, 2009 SCC 32, the Supreme Court defined psychological detention as arising when a reasonable person in the individual’s shoes would conclude they had no choice but to comply, where that perception arises from police conduct such as direction, control, physical presence, or the setting. The Court provided a non-exhaustive list of factors that help determine whether someone is detained, including:

• The circumstances of the encounter (e.g., was the person singled out?)
• The behaviour of police, including tone, commands, and physical positioning
• The individual’s perception, influenced by their age, background, and experience

The purpose of defining detention is to identify the moment Charter protections begin—particularly the right to counsel under section 10(b) and the right to be free from arbitrary detention under section 9.

2. What Grounds Do Police Need to Detain Someone?

Police require reasonable suspicion to detain someone for investigative purposes. This standard was cemented in R. v. Mann, 2004 SCC 52, and again in R. v. Chehil and R. v. MacKenzie. Reasonable suspicion requires:

• More than a hunch or intuition
• Objective, articulable facts; the suspicion must not be based on stereotypes or generalizations
• A connection between the individual and a particular criminal activity

A detention without reasonable suspicion violates section 9 of the Charter (“Everyone has the right not to be arbitrarily detained.)”.

3. What Rights Do You Have When Detained in Ontario?

Detention triggers several crucial rights.

(a)  Section 10 (a) — Right to Be Informed of the Reasons

Police must tell you promptly why you are being detained. The explanation must be clear and specific.

(b)  Section 10 (b) — Right to Counsel

You have the right to:

• Be informed of your right to counsel
• Call a lawyer without delay
• Use a free duty counsel service

In R. v. Suberu, the Supreme Court of Canada directed police to provide access to counsel immediately unless doing so would jeopardize officer or public safety.

(c)  Section 7 — Right to Silence

During detention, you are not required to answer police questions. Statements made during an unlawful or coercive detention may be excluded from evidence at trial.

(d)  Limited Search Protection

Under Mann, police may only conduct a frisk search during an investigative detention when they reasonably suspect a safety risk. They cannot search for evidence during detention—only for safety.

4. What is the remedy if these rights are violated?

If police detain without reasonable suspicion, delay access to counsel, or conduct overbroad searches, the evidence that they obtained may be excluded under section 24(2) of the Charter. Under section 24(2), the trial judge will examine the seriousness of the Charter breach, the impact on the accused’s rights, and society’s interest in adjudicating the case on its merits. Balancing these factors, the judge must exclude the evidence if its admission would bring the administration of justice into disrepute. Many cases in Ontario turn on these issues, especially drug searches, firearm investigations, impaired driving cases, and street-level stops.

Should you be charged with a criminal offence and need legal advice about whether your rights were violated, contact a criminal defence lawyer to receive that advice for a consultation with Brian Ross, call (416) 658-5855.