Under the Criminal Code of Canada, you must act on reasonable grounds to justify using force

Let’s talk about a moment most security pros hope never comes, but must be prepared for: a confrontation where force might be on the table. You’re doing your shift, eyes open, hands ready, and suddenly a threat appears. In Canada, the line you can’t cross is drawn by the Criminal Code. The core idea? You must act on reasonable grounds. That phrase isn’t fuzzy rhetoric; it’s the legal compass that guides every decision to use force.

Reasonable grounds: what it means in the real world

At first glance, “reasonable grounds” can feel abstract. Here’s the straightforward version. To justify using force, a person must reasonably believe that the action is necessary to protect themselves or others from imminent harm. “Imminent” means danger is happening right now or is about to happen very soon. It’s not about what you think might occur later; it’s about the threat as you perceive it in that exact moment.

Reasonableness isn’t a gut instinct or a lucky guess. It’s judged against the standard of a reasonable person in the same situation. That means your training, your observations, the environment you’re in, and the actions you take all get weighed. If, in the moment, you think someone presents a serious threat, and your response is proportional to that threat, you’re more likely to meet the test of reasonableness. If your reaction is out of step with what a cautious observer would deem necessary, trouble follows.

A simple way to picture it: imagine you’re standing in a busy mall corridor. A person charges at you with a weapon-like object but then makes no move to hurt anyone except you. Your first impulse might be defensive, but the law wants you to measure whether your response is the minimum amount of force needed to stop the immediate danger and to do so in a way that reduces risk to bystanders.

Debunking common myths

Let’s clear up a few points that often cause confusion in the field.

• “It’s all about the threat you think you see.” The reality is broader. Reasonable grounds depend on what a reasonable person would think, given the total situation, not just a single interpretation. Your personal fear can’t override the objective assessment.

• “I get to pick the level of force.” Not exactly. The force used must be proportionate to the threat and necessary to prevent harm. It’s not a free pass to escalate simply because you feel cornered.

• “The guard can do whatever to stop someone.” The guard’s authority is bounded by law. Even when you’re trained to step in, your actions must stay within the line of reasonableness.

• “If someone escapes, that justifies more force later.” Not necessarily. The readiness to detain or pursue is also governed by proportionality and safety considerations. The window for force isn’t open-ended.

What counts as imminent and how it plays out

Immediacy is a key hinge. If harm is already happening or about to happen within seconds, courts will scan for whether your response addressed that immediate danger. For example:

• A person lunging with a weapon toward you or others – the immediacy is clear, and a controlled, proportional response may be warranted.

• A verbal confrontation that could explode into violence later – you’re expected to de-escalate and disengage where possible. Force isn’t a default tool for every tense moment.

• A chaotic scene with multiple people and limited visibility – your actions should aim to reduce risk to everyone, not to “win” the encounter.

Defence of self, defence of others, and defence of property

Canada’s laws carve out three core protective principles, but even these have boundaries.

• Self-defence: You may respond to an unlawful attack against you with reasonable force. The goal is to stop the attack, not to punish the attacker.

• Defence of others: If someone else is in imminent danger, you can act to protect them, using a proportionate response.

• Defence of property: You can act to protect property, but the force used must still be reasonable and proportionate to the threat. The bar is lower for people than for immediate safety, and the emphasis remains de-escalation and safety first.

In Ontario, security personnel are guided by both the Criminal Code and provincial frameworks like the Private Security and Investigative Services Act (PSISA). The bottom line is simple: legal permission to use force isn’t a free pass; it’s a tightly guarded permission that depends on the surrounding facts and your conduct.

De-escalation as the default play

Here’s where the craft of security work really shines. A lot of the time, force isn’t the answer. The best outcome is one where people are safe without harm, and conflict is resolved through clear communication, barriers, and controlled distance.

• Verbal cues and calm language can defuse tension.

• Time and space can prevent a spark from turning into a blaze.

• Listening to what the other person wants often reveals a straightforward path to safety.

• If you must engage physically, you do so with minimal force, in a way that reduces risk to bystanders and yourself.

Think of de-escalation as the first and primary tool in your belt. It’s not soft; it’s strategic. The more you can slow a situation down, the more you protect everyone involved and stay within the bounds of “reasonable grounds.”

Documentation, after-action, and accountability

If force is used, the work isn’t done in the moment. You’ll need to document what happened, why you believed force was necessary, what alternatives you tried, and what the outcome was. Clear notes and timely reporting aren’t just bureaucratic red tape; they’re essential to show the chain of reasoning that led to your actions.

This reflective step is important for several reasons:

• It helps reviewers understand your decision-making under pressure.

• It provides a record you can rely on if questions arise later.

• It reinforces the important message that safety and accountability go hand in hand.

Legal exposure isn’t just theoretical. Misjudging a situation or escalating unnecessarily can lead to charges, civil liability, or disciplinary action. Training that emphasizes reasonable grounds and proportionality isn’t just a box to tick—it’s your practical shield and your professional responsibility.

Practical takeaways for Ontario professionals

If you’re working in Ontario, here are some grounded reminders that tie the law to daily duties:

• Ground your decisions in the objective standard of reasonableness. Your personal fear won’t be the deciding factor; the situation, the threat, and the available options will be.

• Prioritize de-escalation and safe outcomes. Use distance, barriers, and voice to reduce risk before considering any physical action.

• Be mindful of bystander safety. In public spaces, your actions affect others. The goal is to stop danger without creating new hazards.

• Know when to retreat and seek help. If the threat remains uncertain or escalates, call for backup and let law enforcement handle the next steps.

• Keep thorough records. A well-documented incident makes a big difference in how the action is interpreted later.

• Stay current with Ontario requirements. PSISA and related guidelines shape how you train, report, and respond. Ongoing education is your best hedge against missteps.

A practical scenario to connect the dots

Let me explain with a hypothetical, relatable moment. Imagine you’re stationed at a transit hub. A person tries to snatch a commuter’s bag. You step in, keep a line of sight, and shout for them to stop. You position yourself between the thief and the victim, use your voice to command space, and slowly move to create a safer buffer. The attacker, sensing the risk of being restrained or questioned, hesitates. The immediate danger to the commuter is reduced, and you’ve avoided escalating into a more chaotic confrontation. Later, you provide a concise incident report, noting the threats, your observations, and the steps you took to mitigate harm. If any doubt arises, you can point to the objective factors: the imminent threat, your proportional reply, and the attempts at de-escalation.

Two quick pointers you’ll carry forward

• Always aim for the least amount of force needed to prevent harm. It’s the core test of reasonableness.

• When in doubt, slow the scene down. Verbal engagement, distance, and barriers can prevent a bad outcome and keep you within legal bounds.

Growing fluency with the law is part of professional maturity

Security work blends people skills with precise legal awareness. You’re not just a guardian of property; you’re a guardian of safety, guided by law and good judgment. The rule that keeps things in check—acting on reasonable grounds—serves as your North Star. It anchors you in decisions you’ll be measured by long after the shift ends.

If you’re curious about how this connects to Ontario’s broader security landscape, you’ll find that the law doesn’t live in a vacuum. It interacts with training standards, reporting obligations, and the everyday realities of crowded venues, construction zones, hospitals, and transit systems. That’s why a solid grasp of when force is justified isn’t just theoretical; it’s a practical skill you’ll use on every shift.

Final take: keep the balance, stay grounded

In the end, the question isn’t about aggression; it’s about responsibility. You must act on reasonable grounds, balancing your right to protect yourself and others with the duty to minimize harm. It’s a discipline—one that improves with training, reflection, and real-world practice.

If you apply this mindset—watchful, measured, and ready to de-escalate—you’ll navigate difficult moments with clearer judgment and greater confidence. And in a field that thrives on calm under pressure, that balance is everything.

Key points at a glance

• The core rule: use force only when you reasonably believe it’s necessary to prevent imminent harm.

• Reasonableness hinges on the threat, the context, and proportionality of your response.

• Self-defence, defence of others, and defence of property have legal allowances, but all actions must be proportionate and necessary.

• De-escalation and safe disengagement are preferred to escalation.

• Documentation and accountability matter as much as the action itself.

• Ontario standards emphasize a blend of legal knowledge, practical judgment, and ongoing training.

If you keep these ideas in mind, you’ll approach tough moments with clarity, and you’ll be ready to protect people while staying firmly within the boundaries the law sets. That balance isn’t flashy, but it’s powerful—and it’s what separates strong, thoughtful security professionals from the rest.