Sources of criminal law: the Criminal Code, statutes and the courts

The first class of Criminal Law for Law Enforcement starts with a question on the whiteboard: what makes something a crime? Professor Ray Desjardins, who spent 28 years with the Port Ardent police before he started teaching at Georgian Shores College, lets the room argue for a few minutes. Marco DiSanto says a crime is anything that hurts someone. Amara Okafor points out that cheating on a partner hurts people and is not a crime, while possessing a prohibited knife hurts no one and is. Priya Sandhu, who spent five years investigating bank fraud, says a crime is whatever the law says it is, and that the hard part is reading what the law actually says. Professor Desjardins circles her answer. This term, he says, the class will learn to read criminal law the way a good officer does: as a set of precise rules, each with elements that must be proved, which tell an officer when there are grounds to act and what evidence to gather. He introduces his co-instructor for the course, assistant Crown attorney Margaret Liu, who reviews police charges in Port Ardent every week and will tell them, often bluntly, which charges survive in court and why.

What criminal law is

Criminal law is the part of the law that defines conduct the state forbids and punishes. Three features separate it from other law. First, a crime is treated as a wrong against society as a whole, not just against the victim, so the case is brought by the state in the name of the King, which is why cases are named R. v. Smith (Rex, or Regina when a queen reigns, against Smith) and the victim is a witness rather than a party. Second, the consequences are the most serious the law imposes: a criminal record, fines, probation, imprisonment and the stigma of conviction. Third, because the stakes are so high, the accused is presumed innocent and the prosecution must prove every element of the offence beyond a reasonable doubt. In Canada this standard is protected by section 11(d) of the Charter, and in R. v. Lifchus (1997) the Supreme Court told judges how to explain it to juries: it is not proof to an absolute certainty, but it is much closer to certainty than to proof on a balance of probabilities.

A civil case is different. If Amara's neighbour damages her fence, she can sue for the cost of repairs; she controls the case, needs to prove it only on a balance of probabilities, and the remedy is money. The same act may be both a civil wrong and a crime. If the neighbour broke the fence deliberately, the state may also prosecute for mischief, and the two cases proceed separately with different standards of proof. Officers deal only with the criminal side, but they should understand the difference, because people often call the police about matters that are purely civil, such as a landlord keeping a damage deposit or a contractor who did poor work. Explaining that something is a civil dispute, and where the person can go for help, is part of the job.

Who makes criminal law

In Canada, the Constitution Act, 1867 divides law-making power between Parliament and the provinces. Section 91(27) gives Parliament exclusive power over the criminal law and criminal procedure, which is why the same Criminal Code applies from St. John's to Victoria. Section 92(14) gives the provinces power over the administration of justice, so provinces run the courts, employ Crown prosecutors for most offences and oversee policing. Section 92(15) lets provinces create penalties to enforce their own laws, which is the source of provincial offences such as speeding under Ontario's Highway Traffic Act. Municipalities can make by-laws only under powers delegated by the province, such as noise and parking by-laws.

Canada's Criminal Code was first enacted in 1892, borrowing heavily from a draft English code that England itself never adopted. It has been amended thousands of times and is now a statute of more than 800 sections, organized into Parts by subject: offences against public order, against the person, against property, and so on, followed by procedure. Many offences are also found in other federal statutes. The Controlled Drugs and Substances Act covers drug offences, the Cannabis Act covers cannabis, the Youth Criminal Justice Act sets the rules for young people aged 12 to 17, and the Firearms Act covers licensing and registration. Parliament continues to change the Code: in June 2026, for example, the Bail and Sentencing Reform Act tightened bail for repeat and violent offending, and the Protecting Victims Act created new offences, including a coercive control offence and offences for threatening to share intimate images.

No crime without a law

A basic principle of criminal law is often stated in Latin as nullum crimen sine lege: there is no crime without a law. People can be punished only for conduct that was clearly defined as a crime before they did it. In Canada, section 9 of the Criminal Code abolished common law offences, the crimes once created by judges rather than legislatures, with the single exception of contempt of court. Section 11(g) of the Charter protects against conviction for an act that was not an offence when it was committed, and section 11(i) gives an accused the benefit of a lesser punishment if the penalty changed between the offence and sentencing. For an officer, this principle means that the question is never whether conduct seems wrong but whether it fits a specific offence. A man who shouts insults at a referee may be rude, but unless his conduct meets the elements of a defined offence, there is nothing to charge.

The same principle requires laws to be clear. A law so vague that ordinary people cannot tell what it forbids, or that leaves police free to arrest whomever they dislike, violates the constitution. In R. v. Nova Scotia Pharmaceutical Society (1992), the Supreme Court of Canada said a law is unconstitutionally vague if it fails to give fair notice to citizens and to limit enforcement discretion, offering no sufficient guidance for legal debate. Old vagrancy laws were once used to move along people whom police or the community considered undesirable, and their history is a reminder that clear limits on police power protect everyone.

The role of the courts

Legislatures write criminal law, but courts decide what the words mean. When a section is ambiguous, judges look at its words in context, its purpose and its history. Because criminal law can take away liberty, a real ambiguity that remains after these steps is resolved in favour of the accused. In R. v. McIntosh (1995), the Supreme Court of Canada applied this principle to a confusing self-defence provision, holding that where a penal provision is reasonably capable of two interpretations, the one more favourable to the accused must be adopted. Courts also develop the general principles that apply to every offence, such as what counts as intent, when an accused caused a result and how defences work. Many of these principles appear in no statute at all and are found only in case law.

Courts are bound by precedent, a principle known as stare decisis. A lower court must follow the decisions of the courts above it. In Ontario, a judge of the Ontario Court of Justice follows the Superior Court of Justice and the Court of Appeal for Ontario, and every court in the country follows the Supreme Court of Canada, which is the final court of appeal for all law in Canada, federal and provincial. This is why Ms. Liu tells the class that a single appeal decision can change how every officer in the province or state must investigate a type of case, and why police services issue training bulletins when an important decision comes down.

Reading a statute like an investigator

Officers do not need to memorize the Criminal Code, but they must be able to find and read the section that fits a situation. Statutes are written in a precise structure. A Criminal Code citation such as section 348(1)(b) means section 348, subsection (1), paragraph (b). Section 348(1) says that every one who breaks and enters a place with intent to commit an indictable offence in it, or breaks and enters a place and commits an indictable offence in it, or breaks out of a place after committing an indictable offence in it or after entering with intent to commit one, is guilty. Each paragraph is a separate way of committing the offence, and the charge must say which one. Every word matters. Definitions sections tell the reader what terms mean, and the same word can have a narrower or broader meaning than in everyday speech.

The code below shows one way to break a citation into its parts, the first step in finding the right provision. Linh Tran, who hopes to become a crime analyst, likes the idea that statutes can be read as structured data. Records systems in police services do exactly this when they let officers select an offence by its section number.

# Breaking a Criminal Code citation into its parts
import re
pattern = re.compile(r"s\. (\d+(?:\.\d+)?)(?:\((\d+)\))?(?:\(([a-z])\))?(?:\((i+|iv|v)\))?")
labels = ["section", "subsection", "paragraph", "subparagraph"]
for citation in ["s. 348(1)(b)", "s. 267(a)", "s. 264.1(1)(a)", "s. 430(4)", "s. 334"]:
    m = pattern.fullmatch(citation)
    parts = [f"{label} {value}" for label, value in zip(labels, m.groups()) if value]
    print(f"{citation:16s} -> " + ", ".join(parts))

s. 348(1)(b)     -> section 348, subsection 1, paragraph b
s. 267(a)        -> section 267, paragraph a
s. 264.1(1)(a)   -> section 264.1, subsection 1, paragraph a
s. 430(4)        -> section 430, subsection 4
s. 334           -> section 334

A citation tells you where to look, but the work starts when you read the provision itself. Ms. Liu gives the class a habit to practise all term: read the whole section, including any definitions it refers to; list its elements one per line; and then, for each element, write down what evidence would prove it. That list becomes the investigator's checklist, and lesson 3 will turn it into a formal tool.

From the street to the charge

Knowing the law matters at every step of police work. Before acting, an officer needs grounds to believe a specific offence has been committed. In Ontario, police lay most charges themselves by swearing an information before a justice of the peace, and the Crown then reviews the charge and decides whether to continue; in British Columbia, Quebec and New Brunswick, Crown counsel must approve charges before they are laid. The Crown continues a prosecution only if there is a reasonable prospect of conviction and it is in the public interest. Choosing the right offence and documenting the evidence for each element is what makes the difference between a case that proceeds and one that collapses.

Ms. Liu describes the most common problems she sees in police files. An officer charges a more serious offence than the evidence supports, perhaps because the victim was very upset, and the case is later reduced or withdrawn. An officer writes that a suspect intended something without recording the words and actions that showed intent. An officer charges the right offence but under the wrong subsection, so the charging document has to be amended. Or the report never addresses an element at all, such as the value of stolen property, which determines the level of the offence. Each of these can be avoided by reading the section and building the file around its elements, which is the core skill of this course.