Facts
Smith was a tenant of a flat. He installed fittings, including wiring and panelling, in the flat. When he left he removed or dismantled these fittings and in doing so damaged parts of the structure belonging to the landlord. He believed that the fittings he had installed belonged to him.
History
He was convicted of criminal damage under section 1(1) of the Criminal Damage Act 1971 at trial and appealed to the Court of Appeal.
Issue
Whether the offence of destroying or damaging property belonging to another without lawful excuse required proof that the defendant knew, or was reckless about, the property belonging to another, and whether an honest but mistaken belief on a point of civil property law could negate that mental element.
Held
Appeal allowed and the conviction quashed. The honest belief of the defendant that the property was his own meant that he lacked the mens rea required for the offence.
Ratio
- Criminal damage requires that the defendant intended to damage, or was reckless as to damaging, property belonging to another. A defendant who honestly believes, even on mistaken grounds in civil law, that the property is his own does not have that mental state, and a mistake of this kind is treated as a mistake of fact and not as ignorance of the criminal law.
The judgments
Edmund Davies LJ (lead)
Delivered the judgment of the court. He held that the mental element of the offence was concerned with what the defendant knew of the nature of the property, that a mistake about property rights in civil law could negate it, and that the jury should have been directed accordingly.
Key reasoning
- Ignorance or mistake about the criminal law is no defence, but a mistake about a rule of civil law that determines whether property belongs to another goes to an element of the offence.
- What the defendant believed about ownership of the fittings was relevant because the offence concerns damage to property belonging to another, and a person who thinks the property is his own lacks the required state of mind.
- The honesty of the belief is the test, and it is not necessary that the belief was reasonable.
Where it fits in the module
In the Property Offences topic the case marks the treatment of mistake as to property rights in offences against property, and offers a contrast with offences where ignorance of law is no excuse. The module debates how far the criminal law should accommodate mistakes about civil entitlement, and whether this is consistent with the maxim that ignorance of the law is no defence. It should be read with the statutory defence of lawful excuse in section 5 of the Criminal Damage Act 1971, which turns on honest belief in consent or entitlement, and with the dishonesty provisions in theft.
Criticisms
- The distinction between a mistake of civil law, which excuses, and a mistake of criminal law, which does not, is hard to draw in principle since any mistake about rights is a mistake about law.
- Setting the test at honest belief, without any requirement of reasonableness, makes the rule easy to claim and difficult to disprove.
- The case turned on the structure of the offence of criminal damage, so its principle may be limited to offences defined by reference to civil law concepts such as ownership.
Written with AI (claude-sonnet-5.5 (Claude Code writer)) on 1 November 2026, reviewed for errors by a second model (claude-sonnet-5.5 (Claude Code checker)). Read the case itself at [1974] QB 354, [1974] Crim. L.R. 101. Spotted an error? Tell us.