The purpose of criminal law is to protect the public while holding people accountable through a fair legal process. The nature of criminal law in Canada is that it addresses conduct Parliament has made an offence, sets consequences for proven offences, and places limits on how the state can investigate and prosecute people.

For someone under investigation or charged, these ideas are practical, not academic. They affect what police must prove, what rights an accused person has, and what can happen in court.

This overview explains the criminal law definition, its functions, and the steps that often follow an allegation in Ontario.

What Is the Nature of Criminal Law in Canada?

Criminal law is public law: it deals with conduct considered harmful to people or society, and the state brings the prosecution. It is not simply a dispute between two private people. It concerns public safety, accountability, and safeguards against unfair use of state power.

Most Canadian criminal offences are created by federal legislation, especially the Criminal Code. Police investigate allegations, but the Crown decides whether to prosecute and must prove the allegation in court. A person facing an allegation should understand that an accusation is not a finding of guilt.

If you need advice about an investigation or charge, a criminal lawyer Toronto can assess the allegation, the available information, and the immediate steps that may protect your position.

What Is the Purpose of Criminal Law?

The main purpose of criminal law in Canada is to support a safe, just, and peaceful society without abandoning fairness to people accused of offences. Its broad purposes can be described as protecting the public, holding people accountable when guilt is proven, and ensuring that the process is fair.

These are often described as the three main purposes of criminal law, but they are not a rigid legal checklist. Public protection may call for restrictions in some cases, while fairness requires reliable evidence, an impartial hearing, and a meaningful opportunity to defend the allegation.

The purposes of sentencing are more specific. After a finding of guilt, a judge considers objectives set out in section 718 of the Criminal Code, including denunciation, deterrence, rehabilitation, reparation, and promoting responsibility.

Five Functions of Criminal Law

Five useful functions of criminal law are defining prohibited conduct, protecting people and communities, denouncing wrongdoing, deterring harmful conduct, and providing a fair process for deciding responsibility. These functions explain both why offences exist and why proof and procedure matter.

• Define conduct: legislation tells the public what behaviour is prohibited.
• Protect: offences address harms such as violence, theft, impaired driving, and drug trafficking.
• Denounce: a conviction and sentence can communicate society’s condemnation of proven wrongdoing.
• Deter: legal consequences may discourage the person involved and others from harmful conduct.
• Decide fairly: the process requires the Crown to prove guilt and allows an accused person to answer the case.

In an individual case, these functions can pull in different directions. For example, a person charged after a bar fight may face an allegation intended to address public safety, but the court must still examine whether the person acted in self-defence and whether the Crown can prove the required facts.

The Nature and Scope of Criminal Law

The nature and scope of criminal law extend beyond the Criminal Code, although the Code is its central statute. Other federal laws, including the Controlled Drugs and Substances Act, create criminal offences; the Canada Revenue Agency Act mainly governs the CRA’s organization and mandate rather than serving as a general source of criminal offences.

Criminal law differs from civil law. A civil case usually concerns a private claim, such as damages after a breach of contract or injury, while a criminal case concerns an alleged offence prosecuted by the state and may lead to a criminal sentence. For more on how counsel approaches an allegation, read about criminal defence law.

Offences can be summary, indictable, or hybrid, and each offence has its own wording and possible consequences. The classification and the facts alleged can affect how a case proceeds.

What Makes Conduct Criminal?

Conduct is criminal only when it fits an offence created by law and the prosecution can prove its required elements. Usually, those elements include a prohibited act or omission, called actus reus, and a required fault element, often called mens rea.

Mens rea can mean intent, knowledge, recklessness, wilful blindness, or another state of mind specified by the offence. Some offences also require proof that the accused caused a particular result. For aggravated assault, for example, the Crown must prove the injury required by the offence, not merely that an unwanted touch occurred.

A lawful defence can change the result even where an act occurred. Self-defence may apply where a person reasonably acted to protect themselves or another person, depending on all the circumstances. A clear definition of a criminal act and common terms is available in this court terminology Canada resource.

Key Characteristics of Canadian Criminal Law

Canadian criminal law starts with the presumption of innocence: an accused person is not required to prove innocence. The Crown must prove every essential element of the offence beyond reasonable doubt, the high standard required before a criminal conviction.

Fault matters, but the required fault depends on the particular offence. True criminal offences generally require proof of a fault element, while some regulatory offences are classified as strict liability and may permit an accused to avoid liability by showing due diligence.

Double jeopardy is an important protection against being tried or punished again for the same offence after a matter has been finally decided. It does not mean that every later court proceeding is impossible, because appeal procedures can affect a conviction or acquittal.

Substantive Criminal Law and Criminal Procedure

Substantive criminal law defines offences, defences, and potential penalties; criminal procedure governs how the case moves from investigation to resolution. Procedure includes police powers, arrest or summons, release or bail, disclosure, Crown screening, court appearances, trial, and sentencing.

For example, consider someone charged with shoplifting after leaving a Toronto store with unpaid electronics. The substantive question is whether the Crown can prove theft and the required intent. The procedural questions include whether the person is released on conditions, what video and witness evidence is disclosed, and whether the case resolves or goes to trial in the Ontario Court of Justice.

Timelines vary widely. A straightforward matter may resolve after disclosure is reviewed, while a contested trial can take much longer because court dates, evidence, and legal issues must be addressed. Learn more about the stages of a criminal case in Canada.

What Happens When Criminal Law Affects You in Ontario?

If police contact you or you are charged, do not guess, volunteer an explanation, or try to solve the allegation through informal conversations. Ask whether you are detained or free to leave, say that you want to speak with a lawyer, and avoid discussing the facts until you have legal advice.

• Preserve relevant messages, photographs, documents, and names of potential witnesses; do not alter or delete material.
• Read and follow every release, bail, or probation condition, including no-contact or geographic restrictions.
• Have counsel obtain and review disclosure, which is the information the Crown provides about its case.
• Get advice promptly about deadlines, court dates, possible defences, and the consequences of decisions you make.

A defence lawyer examines whether the Crown can prove each required element, whether evidence is reliable, and whether the process respected the accused person’s rights. For a broader overview of those protections, see know your rights.

Frequently Asked Questions About Criminal Law

What is criminal law?

Criminal law is the body of public law that defines offences, provides legal consequences, and regulates how the state investigates and prosecutes alleged offences. Its focus is conduct Parliament has prohibited because of its actual or potential harm.

What does the nature of a crime mean?

The nature of a crime means the legal and factual character of the allegation: what conduct is alleged, what mental state is required, who was affected, and what harm or risk is said to have occurred. Those details affect the available defences, court process, and potential sentence.

What is criminal law concerned with?

Criminal law is concerned with prohibited conduct, public safety, individual responsibility, and a fair process for determining guilt. It is not concerned only with punishment; it also limits state power through rules of proof, procedure, and constitutional rights.

Which type of law is criminal law?

Criminal law is public law. In Canada, Parliament has primary authority to enact criminal law, while provinces administer justice, including courts and prosecutions in Ontario.

What is a simple example of a criminal law?

The Criminal Code offence of theft is a simple example: taking or converting someone else’s property with the required dishonest intent can be a crime. Whether a particular event amounts to theft depends on the evidence and the legal elements, not simply on an accusation.

For additional answers to common questions, visit the general criminal law faq.

Speak with a Toronto criminal defence lawyer

Early legal advice can help you understand the allegation, protect your rights, and respond appropriately to police contact, release conditions, or an upcoming court date.

Call 647-351-HELP (4357) or book a free consultation to discuss your case with Jeffrey I. Reisman.