7.2 Use of Force, Self-Defence & Criminal Liability

In the private investigative profession, physical confrontation represents an absolute failure of operational tradecraft. Investigators are hired to gather factual evidence, locate missing persons, and document illicit conduct—not to enforce public order, subdue suspects, or engage in hand-to-hand combat. However, field operatives working in volatile environments may encounter hostile subjects, aggressive property owners, or dangerous bystanders.

Every licensed investigator must understand the precise legal boundaries governing physical force under the Criminal Code of Canada (R.S.C. 1985, c. C-46). Under Canadian law, a private investigator holds no special statutory shield. Any physical contact or threat of violence that cannot be strictly justified under federal statute constitutes a criminal assault.

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Authority to Use Force: Criminal Code Section 25

Section 25 of the Criminal Code provides a general legal justification for individuals who are required or authorized by law to use force in the enforcement of the legal order.

Criminal Code Section 25(1): Every one who is required or authorized by law to do anything in the administration or enforcement of the law [...] is, if he acts on reasonable grounds, justified in doing what he is required or authorized to do and in using as much force as is necessary for that purpose.

The Critical Reality for Private Investigators

A foundational doctrine tested on Ontario licensing examinations is that holding a private investigator licence confers zero special use-of-force powers. An investigator is not a peace officer. An investigator's authority to use force is strictly identical to that of any ordinary private citizen:

1. Authority Comes from a Lawful Arrest or Other Legal Power: An investigator can rely on s. 25 only when doing something they are authorized by law to do, most often a lawful citizen's arrest. Criminal Code s. 494(4) confirms that a person authorized to arrest under s. 494 is authorized by law for s. 25 purposes, and an occupier's authorized agent under the Trespass to Property Act (s. 9) is in the same position. If the underlying arrest is unlawful, any force used to touch, restrain or detain the subject is an assault.
2. The Strict Test of Necessity: The statutory phrase "as much force as is necessary" establishes that force must be the last resort. If a suspect can be monitored until police arrive, or if verbal de-escalation can defuse the encounter, physical force is legally unnecessary and therefore unlawful.
3. Proportionality: The degree of force applied must match the resistance encountered. Using physical violence against a passive, non-compliant shoplifter who merely refuses to answer questions is completely unlawful.

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Criminal Responsibility for Excessive Force: Criminal Code Section 26

Canadian law imposes severe criminal liability on any individual who abuses authorized force. Section 26 functions as a statutory warning for all private security and investigative personnel.

Criminal Code Section 26: Every one who is authorized by law to use force is criminally responsible for any excess thereof according to the nature and quality of the act that constitutes the excess.

Practical Implications of Section 26

• Loss of Statutory Protection: The moment an investigator applies more force than is reasonably necessary, the protective shield of Section 25 evaporates entirely. The operative stands before the court stripped of legal justification.
• Criminal Charges for Excess Force: If an investigator initiating a lawful arrest under Section 494 encounters initial physical resistance, but continues striking, kicking, or applying chokeholds to the subject after the subject has been pinned or ceased resisting, the investigator has committed a criminal offence. The investigator will be prosecuted for Assault (Section 265), Assault Causing Bodily Harm (Section 267), or Aggravated Assault (Section 268).
• Civil Consequences: The victim of excessive force can file a civil action in the Ontario Superior Court of Justice, resulting in substantial general, special, and punitive damage awards against both the individual investigator and their employing agency.

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Preventing an Offence: Criminal Code Section 27

The ministry's study guide also highlights s. 27. Everyone is justified in using as much force as is reasonably necessary to prevent the commission of an offence:

• for which the offender could be arrested without warrant, and
• that would be likely to cause immediate and serious injury to any person or property,

or to prevent anything that they believe on reasonable grounds would be such an offence. Section 27 does not authorize force to stop a minor or non-violent offence, such as a person walking away with an inexpensive item. Its threshold is immediate and serious injury.

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The Reformed Self-Defence Framework: Criminal Code Section 34

In 2012, Parliament enacted the Citizen's Arrest and Self-defence Act, completely overhauling Canada's convoluted historical self-defence laws and establishing a unified, coherent statutory framework under Section 34 of the Criminal Code.

Criminal Code Section 34(1): A person is not guilty of an offence if:

(a) they believe on reasonable grounds that force is being used against them or another person or that a threat of force is being made against them or another person;

(b) the act that constitutes the offence is committed for the purpose of defending or protecting themselves or the other person from that use or threat of force; and

(c) the act committed is reasonable in the circumstances.

The Three Cumulative Statutory Criteria

To successfully establish self-defence, all three criteria must be proven simultaneously:

1. Subjective and Objective Perception of Threat (s. 34(1)(a)): The investigator must genuinely believe that force is being applied or threatened, and that belief must be reasonable from an objective standpoint. Paranoia or unreasonable panic does not satisfy this requirement.
2. Defensive Purpose (s. 34(1)(b)): The physical action must be taken solely for the purpose of personal protection or defending another innocent person. Physical retaliation, vengeance, punishing a disrespectful subject, or "teaching someone a lesson" completely negates self-defence.
3. Reasonableness in the Circumstances (s. 34(1)(c)): The response must be objectively reasonable when measured against the threat.

Statutory Factors for Determining "Reasonable Conduct" (Section 34(2))

Under Section 34(2), the court must consider several specific statutory factors when assessing whether an investigator's defensive conduct was reasonable:

• Nature of the Force or Threat: Was the attacker wielding a weapon or displaying bare hands?
• Imminence of the Threat: Was physical violence immediately about to occur, or was there time to retreat, enter a surveillance vehicle, lock the doors, and drive away?
• Availability of Alternatives: Could the investigator have safely disengaged or called 911 rather than fighting?
• Comparative Physical Disparities: The size, age, gender, and physical capabilities of the parties involved;
• Proportionality of the Response: Striking an unarmed person with a heavy metal flashlight in response to a verbal insult or a minor push is completely disproportionate;
• Role in the Incident: Did the investigator provoke the encounter through aggressive posturing, trespassing, or instigating a confrontation?

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Defence of Property: Criminal Code Section 35

Section 35 of the Criminal Code governs the use of force to protect property:

Criminal Code Section 35(1): A person is not guilty of an offence if they believe on reasonable grounds that they are in peaceable possession of property (or acting under authority of someone in peaceable possession), and they believe on reasonable grounds that another person is about to enter, entering, damaging, or taking the property, and the act committed is for the purpose of preventing that interference, and the act committed is reasonable in the circumstances.

Boundaries of Property Defence for Investigators

• Peaceable Possession Required: The client or investigator must be in lawful possession of the property. You cannot use force to recover property if possession is disputed or has already ceased.
• Absolute Prohibition on Grievous Harm or Deadly Force: Canadian law places human life and bodily integrity far above property rights. Lethal force, firearms, bludgeoning instruments, or inflicting serious bodily injury is never reasonable solely to protect property.
• Retreat and Police Notification: When faced with property theft or vandalism where no human lives are endangered, the professional and lawful response is to record evidence, note descriptions, and immediately contact local police.

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Strict Prohibition on Weapons in Ontario Investigative Practice

Ontario maintains some of the most rigorous private security regulations in North America under the Private Security and Investigative Services Act, 2005 and its associated regulations.

Weapons and Equipment Matrix

The ministry confirms that private investigators may use batons and handcuffs if they are issued by their employer. Most investigation agencies do not issue them, because investigative work rarely justifies the risk, the training burden and the reporting obligations.

Operational Rules Regarding Weapons & Restraints

1. Do not improvise weapons: Carrying an item such as a knife, weighted flashlight or unissued baton intending to use it as a weapon risks charges such as possession of a weapon for a dangerous purpose (s. 88) or carrying a concealed weapon (s. 90). An employer-issued baton must be carried for defensive purposes only.
2. Chemical irritants are prohibited weapons: Pepper spray and tear gas designed for use on people are prohibited weapons, and possessing them is an offence under s. 91.
3. Restraints bring paperwork and liability: An agency that issues handcuffs must keep training evidence, insurance, an equipment log and a use-of-force report for every use (O. Reg. 434/07). Handcuffing someone during an unlawful detention is an assault and can support a charge of assault with a weapon (s. 267) and a civil claim.

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Criminal Code Section 265: Statutory Definition & Degrees of Assault

Private investigators frequently misinterpret the legal threshold of assault, believing that physical injury or actual striking is required. Under Canadian law, assault is defined expansively.

Criminal Code Section 265(1): A person commits an assault when:

(a) without the consent of another person, he applies force intentionally to that other person, directly or indirectly;

(b) he attempts or threatens, by an act or a gesture, to apply force to another person, if he has, or causes that other person to believe on reasonable grounds that he has, present ability to effect his purpose; or

(c) while openly wearing or carrying a weapon or an imitation thereof, he accosts or impedes another person or begs.

Three Critical Legal Principles of Assault

1. No Physical Harm Required (Section 265(1)(a)): Any intentional, non-consensual physical contact constitutes assault. Grabbing someone's arm, pinning a subject against a wall, knocking a smartphone or camera out of a person's hand, or spitting on someone satisfies the physical act of assault.
2. Assault by Threat or Gesture (Section 265(1)(b)): An investigator who raises their fists, advances aggressively, brandishes an object, or verbally threatens physical violence while possessing the apparent physical ability to carry out the threat has committed a criminal assault—even if no physical contact ever occurs.
3. Degrees of Criminal Assault:
   • Simple Assault (Section 266): Hybrid offence punishable upon indictment by up to 5 years imprisonment.
   • Assault with a Weapon or Causing Bodily Harm (Section 267): Committing an assault while carrying, using, or threatening to use a weapon or imitation, or causing bodily harm (hurt or injury that interferes with health or comfort and is more than merely transient or trifling). Hybrid offence carrying up to 10 years imprisonment.
   • Aggravated Assault (Section 268): Wounding, maiming, disfiguring, or endangering the life of the complainant. Indictable offence carrying up to 14 years imprisonment.

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Practical Case Scenarios for Field Investigators

Scenario 1: Cornered Operative & Defensive Tactics

An investigator conducting mobile surveillance is followed into a dead-end commercial cul-de-sac by a subject who realizes they are being watched. The subject exits their vehicle, screams profanities, and marches toward the investigator's driver-side door with a heavy tire iron raised above their shoulder. The investigator reverses their vehicle rapidly, turns around, and escapes the area while immediately dialing 911.

• Legal Analysis: The investigator exercised flawless judgment. Under Section 34 of the Criminal Code, self-defence requires that actions be reasonable in the circumstances, considering available alternatives. Retreating safely in a vehicle neutralized the imminent threat without physical violence, avoiding the catastrophic criminal and civil liabilities of a physical or vehicular altercation.

Scenario 2: Shoplifting Restraint & Excessive Force

An investigator acting as an authorized store loss prevention agent apprehends a shoplifter outside a retail store. The suspect drops the stolen merchandise, apologizes, and attempts to pull their arm away to walk toward the bus stop. The investigator executes a forceful leg sweep, throwing the suspect face-first onto the concrete sidewalk, fracturing the suspect's nose and jaw, and then kneels on the suspect's neck.

• Legal Analysis: Even if the initial citizen's arrest was lawful under Section 494, the investigator used grossly excessive force under Section 26. Striking and severely injuring a non-violent, disengaged suspect constitutes Assault Causing Bodily Harm (Section 267). The investigator faces criminal charges, personal civil litigation, and immediate revocation of their PSISA licence.