In Ontario, mischief is a criminal offence defined under sections 430–432 of the Criminal Code of Canada.
A person commits mischief when they wilfully damage, destroy, alter, or interfere with property, or when they obstruct, interrupt, or interfere with the lawful use, enjoyment, or operation of property.
Mischief can involve physical damage, but it can also include non-physical interference, such as tampering with data or disrupting computer systems.
A key element of mischief is intent. The Crown must prove that the accused acted wilfully, meaning they meant to cause the damage or were reckless as to whether their actions would cause harm. Accidental damage does not meet the threshold.
Common examples of mischief include:
Mischief charges are categorized based on the type and value of the property affected. The most common distinctions are mischief under $5,000 and mischief over $5,000, with the latter carrying more severe penalties. There are also special categories, such as mischief relating to religious property, educational institutions, war memorials, or cultural property, which carry elevated penalties due to public interest concerns. Mischief to data is also a specific and increasingly relevant offence in the digital era.
Penalties for mischief can include fines, probation, restitution, or jail, depending on the seriousness of the damage and the presence of aggravating factors. Even minor mischief can result in a criminal record.
Defences may involve arguing lack of intent, mistaken identity, lawful authority, or violations of Charter rights during the investigation.