Thunder Bay residents who intervene in suspected shoplifting could face criminal charges and civil lawsuits. Learn the limits of citizen’s arrest in Canada.

Intervening in a suspected theft can lead to assault charges, unlawful confinement allegations and a civil lawsuit if the response crosses legal limits

THUNDER BAY — Grabbing a suspected shoplifter, blocking their escape or chasing them down can put the person intervening on the wrong side of the law. Canada permits citizen’s arrests in specific circumstances, but an unlawful detention or excessive force can expose someone to criminal charges and civil liability.

Over the past weeks and months, on social media many people in our community have shared what they have seen in local shops and stores as shoplifters walk out the door with stolen merchandise.

I witnessed a man at the Thunder Centre Home Depot who walked out the door with well over $2000 in merchandise. Store staff in these kinds of cases tell customers they are not allowed to intervene.

This has generated frustration for many people who express that all the theft is causing additional costs for all legitimate consumers. Some on Facebook have posted about taking action themselves.

For people considering taking matters into their own hands, the central question is whether the arrest and any force used are legally justified. Believing someone stole merchandise does not give a person unrestricted authority to detain or hurt them.

Justice Canada’s guide to citizen’s arrest puts its advice plainly: “Whenever possible, you should report wrongdoing to the police instead of taking action on your own.”

A documented concern in Thunder Bay

Retail theft is a local policing issue. On April 20, 2026, Thunder Bay Police Service reported that Project Eclipse had resulted in the seizure of more than $39,000 in stolen items and 256 charges.

Thunder Bay Police said the investigation ran from September 2025 through February 2026 and examined thefts and robberies involving numerous Thunder Bay businesses. The charges included shoplifting and other offences.

Those are police-reported investigation results, not a measure of the current shoplifting rate. Charges are allegations, and accused persons are presumed innocent unless proven guilty.

A customer and a store owner do not have identical arrest powers

Section 494 of the Criminal Code allows anyone to arrest a person they find committing an indictable offence. It also covers a person reasonably believed to have committed a criminal offence who is escaping and being freshly pursued by someone with lawful arrest authority.

Theft involving $5,000 or less is a hybrid offence: it can be prosecuted by indictment or summary conviction. Its dollar value alone does not rule out a citizen’s arrest. That follows from section 334 and the Interpretation Act’s treatment of indictable offences.

Property owners, lawful possessors and people they authorize have an additional power. After finding someone committing an offence involving that property, they may arrest them immediately or within a reasonable time if they reasonably believe police cannot feasibly make the arrest.

That delayed-arrest provision does not automatically extend to an unrelated customer. Recognizing someone from a Facebook post does not itself establish lawful arrest grounds.

Anyone making a citizen’s arrest must hand the person over to police without delay.

A lawful arrest does not permit unlimited force

Under section 25, someone legally authorized to make an arrest and acting on reasonable grounds may use the force necessary for that purpose. Section 26 makes a person criminally responsible for excessive force.

The distinction matters. Force necessary to carry out a lawful arrest and blows delivered to punish someone are different acts. Continuing to hit a person who is already restrained can create criminal exposure even if the original arrest was lawful.

Anger over repeated thefts does not expand those powers.

For a civilian making an arrest, section 25(3) also restricts force intended or likely to cause death or grievous bodily harm. It requires a reasonable belief that such force is necessary to protect the intervener or someone under their protection from death or grievous bodily harm. Protecting merchandise alone does not meet that condition.

What criminal charges could follow?

Depending on the circumstances, an intervention can raise several legal issues:

• Assault: Intentionally grabbing, shoving or striking someone without consent and without a lawful justification can constitute assault. An injury is not required for the basic offence.
• Forcible confinement: Detaining, imprisoning or forcibly seizing someone without lawful authority can fall under this offence. Calling the detention a “citizen’s arrest” does not establish that authority.
• Weapons offences: Carrying a weapon for a purpose dangerous to the public peace or to commit an offence can create separate criminal exposure. A plan to confront suspected shoplifters does not excuse unlawful weapon possession.

These are possible offences, not automatic outcomes. Police, prosecutors and courts must assess the evidence and any applicable defence.

Self-defence and protecting property have separate rules

Section 34 permits reasonable defensive action when someone reasonably believes force is being used or threatened against them or another person, and acts to protect against it.

A suspected theft alone is not an attack on a person. If a confrontation becomes violent, courts consider the threat, available alternatives, proportionality and the intervener’s own role in the incident. Starting or escalating a confrontation can therefore matter to a self-defence claim.

Section 35 provides a separate defence for reasonable acts to protect property, subject to conditions involving possession, authority or lawful assistance, and the purpose of the act.

It is not a general licence for members of the public to punish suspected thieves.

A civil lawsuit can follow, too

Justice Canada expressly warns that someone making a citizen’s arrest may face a civil lawsuit over their conduct and injuries they cause.

An unjustified detention can lead to a claim for false imprisonment. Unjustified physical contact can also lead to a civil claim for battery, the legal term for harmful or offensive contact. The Supreme Court of Canada has addressed the protection of bodily integrity in Non-Marine Underwriters, Lloyd’s of London v. Scalera, 2000 SCC 24.

Ontario law also contains a distinction worth understanding. A Canadian Bar Review analysis explains that a 2016 Ontario ruling recognized a limited shopkeeper’s privilege for brief investigative detention based on a reasonable belief of theft. That concerns shopkeepers and their agents; it is not a general investigative power for customers or vigilante groups.

A lawsuit can mean defending the claim and potentially paying damages. Under section 131 of Ontario’s Courts of Justice Act, a court also has discretion to order payment of litigation costs.

Why staff may be told to let someone leave

An instruction to avoid confrontation can reflect worker-safety concerns. In published guidance for lone retail workers, WorkSafeBC advises workers not to put themselves at risk during robbery or shoplifting.

That is safety guidance from British Columbia, not an Ontario rule requiring every store to let suspects leave. Specific employer policies must be checked with the retailer.

A workplace policy and legal arrest authority are separate questions. Staff declining to intervene does not give a customer additional powers.

What witnesses can do

Justice Canada recommends reporting wrongdoing to police. Its guidance says an arrested person must be transferred promptly to police and cautions citizens against questioning or searching the person or their possessions.

For witnesses, a practical response is to alert staff, keep a safe distance, note what they actually observed and preserve relevant evidence for police without pursuing a suspect.

Thunder Bay Police Service lists 911 for emergencies and 807-684-1200 for non-emergencies.

A witness’s clear account can help an investigation. Physical intervention brings additional risks that a social-media call to “do something” cannot resolve.

This is not legal advice but rather an overview of the legal situation that a person deciding to intervene in a criminal incident.