Defences in Criminal and Penal Law

Criminal Law

The defence of impossibility

This defence applies when it is proven that the accused did not contribute to the occurrence of the uncontrollable event at issue. There are two types of impossibility: absolute impossibility, which negates the actus reus (the guilty act), and relative impossibility, which is moral in nature. The latter cannot be successfully invoked on its own.

The defence of impossibility applies the maxim « the impossible cannot be required » and excuses unforeseeable pollution events.

Paule Hallé, Environmental Penal Law, Cowansville, Éditions Yvon Blais, 2001

In environmental law, a chain chemical reaction that a company was unable to resist because it resulted from a fortuitous weather event could constitute a defence of impossibility. This would be a case of absolute impossibility: it is not that the company had the means to counter this reaction and did not do so, but rather that it was materially impossible for it to do so. This defence is closely related to the concept of force majeure, which is used more often in civil law.

In Notre-Dame-des-Prairies (Municipalité de) v. Coutu, 2009 QCCM 251, a judge acquitted a driver who had failed to make his mandatory stop, because the stop sign was covered in snow. Since it was impossible to see, the defence of impossibility was accepted. So, even though failing to make a mandatory stop under section 368 of the Highway Safety Code is a strict liability offence, where reasonable diligence and/or reasonable mistake of fact are not admissible defences, the defence of impossibility was successfully invoked.

The defence of relative impossibility must be paired with a due diligence defence to be accepted.

The defence of automatism

The defence of automatism can be likened to the defence of impossibility, since it also negates the actus reus. It differs from it, however, in that it applies when the accused denies the moral culpability of an act they did in fact commit, but which resembles a reflex. They must therefore demonstrate the absence of conscious control over their actions.

Automatism sometimes refers to a state in which the accused, due to extreme intoxication, acts involuntarily, without any real intention or control over their movements. Since the codification of section 33.1 of the Criminal Code, this defence may only be invoked for crimes requiring a specific mens rea (guilty intent).

Automatism can also result from severe psychological trauma or a state of sleepwalking, for example.

Courts generally distinguish two categories of automatism: automatism with mental disorder and automatism without mental disorder. This distinction is important since it leads to different legal consequences.

Automatism caused by a mental disorder falls under the regime of not criminally responsible on account of mental disorder set out in the Criminal Code (s. 16 Cr.C.). In this case, the accused may be found not criminally responsible, which sometimes leads to the involvement of a Review Board tasked with assessing risks to public safety (Part XX.1 Cr.C.).

Conversely, automatism without mental disorder — sometimes called « non-mental disorder automatism » — can lead to a full acquittal.

The accused must present evidence showing that the state of automatism was severe enough to abolish voluntary control over their actions. A simple lapse in memory, a state of anger, or strong emotion are not enough. Courts usually require credible medical or psychiatric evidence to establish the actual existence of this involuntary state.

In R. v. Parks, [1992] 2 SCR 871, the Supreme Court of Canada recognized that sleepwalking could, in certain circumstances, constitute a form of non-mental disorder automatism. This defence was therefore treated as automatism without mental disorder.

In that case, the accused had driven his vehicle several kilometres and then violently assaulted his in-laws while sleepwalking. No fewer than five expert testimonies were presented to support Mr. Parks’s position. The Court concluded that he was not voluntarily in control of his actions at the time of the events, and it acquitted him.

The defence of automatism remains exceptional, since courts must reconcile public protection with the fundamental principle of voluntary responsibility. Each situation is analyzed according to its particular facts, the credibility of the medical evidence presented, and the context surrounding the commission of the offence.

The defence of due diligence

Due diligence is a defence that applies when the accused took all reasonable steps to avoid committing the offence. This means that, even though the prohibited act was committed, the accused acted with care and prudence. This defence cannot be accepted for absolute liability offences. Only strict liability offences or criminal offences may be subject to such a defence.

The Supreme Court of Canada recognized this defence in R. v. Sault Ste-Marie, [1978] 2 SCR 1299, which established the distinction between absolute liability offences and strict liability offences. For strict liability offences, the accused may avoid conviction by showing that they took all reasonable steps to prevent the offence, or that they reasonably believed in a mistaken set of facts that, had they existed, would have rendered their act legal.

Unlike traditional criminal offences, where the Crown often must prove guilty intent (mens rea), strict liability offences rest essentially on the commission of the prohibited act. However, the accused can clear themselves by showing they acted with care and diligence.

In Lévis (Ville) v. Tétreault, [2006] 1 SCR 420, the Supreme Court of Canada clarified the limits of this defence in the context of offences under the Highway Safety Code.

In that case, Mr. Tétreault was driving a vehicle while his driver’s licence had expired. He argued that he believed the date on his licence was a payment due date rather than the licence expiry date, and claimed he expected to receive a renewal notice from the Société de l’assurance automobile du Québec.

The Supreme Court, however, rejected this defence. Justice LeBel noted that due diligence requires more than simple passive expectation. According to the Court, a citizen must actively seek to know and comply with their legal obligations. Believing a notice will be sent, or assuming an administrative body will automatically remind you of a deadline, does not constitute sufficient precaution.

So, since Mr. Tétreault had not taken concrete steps to verify the status of his driver’s licence before the known expiry date, the due diligence defence could not be accepted.

This decision clearly illustrates that due diligence rests on an objective standard. Courts assess the accused’s conduct by comparing it to that which a reasonable person placed in the same circumstances would have adopted.

The defence of necessity

The defence of necessity applies when a person commits an act prohibited by law to avoid an imminent danger. For example, if you are forced to break a rule to protect your life or someone else’s, this defence may apply.

To be admissible, it must be shown that (Perka v. The Queen, [1984] 2 S.C.R. 232; R. v. Latimer, 2001 SCC 1):

• The act was necessary to avoid an imminent danger.
• There was no other reasonable way to avoid this danger.
• The act committed was proportional to the danger avoided.

This defence is often difficult to prove, as it involves judging an emergency situation and a subjective assessment of the proportionality of the act.

In Directeur des poursuites criminelles et pénales v. Lallier, 2010 QCCQ 13264, the court acquitted Dr. Michel Lallier, a pediatric surgeon who was driving his vehicle at 123 km/h in a 70 km/h zone at 2:28 a.m. on Highway 40. Dr. Lallier was on call the night of February 16, 2009. He received a call at his residence in St-Léonard informing him that a six-year-old child was being transferred to Ste-Justine Hospital from Maisonneuve-Rosemont Hospital, due to septic shock following an intra-abdominal abscess with peritonitis. Since he needed to get to the scene quickly to save the child, Dr. Lallier was acquitted.

The defence of alibi

An alibi is a classic defence that consists of proving that the accused could not have been present at the scene of the crime at the time of the alleged events. To succeed with this defence, serious evidence must be provided, such as a sworn witness statement, videos, or documents confirming your presence elsewhere. It is also best to disclose this defence in advance to strengthen its probative value. An alibi raised as a surprise at trial has less chance of success.

An alibi is often one of the first defences considered, as it directly calls into question the very possibility that the accused committed the offence.

How a lawyer can help you use these defences

A lawyer specialized in criminal law knows the subtleties of these defences and can advise you on the best strategy to adopt.

At Lacroix Tarabay Légal, we offer legal support services tailored to each situation. Our team can help you prepare your defence, whether it involves an alibi, necessity, or due diligence.

Why it is important to discuss your defence with a professional

Every case is unique. The possible defences depend on the specific facts, the available evidence, and the applicable case law. A defence that works in one case may not be admissible in another.

Conclusion

Defences in Canadian criminal law are varied and complex. The defence of impossibility, due diligence, the defence of necessity, and alibi are among the most common. Each rests on precise criteria that must be rigorously demonstrated.

To maximize your chances of success, it is crucial to retain a competent lawyer who can analyze your case and choose the best defence. Me Alexandre Lacroix can help you better understand your chances of success and prepare your defence.

This blog post is provided for general informational purposes only and does not constitute legal advice. Every situation is unique — consult a legal professional for advice tailored to your case.