R v Williams (Gladstone)

Facts

Williams saw a man, Mason, seize a youth in the street. Williams believed that Mason was attacking the youth, but in fact Mason had seen the youth robbing a woman and had caught hold of him to arrest him. Williams intervened and struck Mason, causing injury. Mason told him that he was a police officer, but could not produce a warrant card.

History

Williams was convicted of assault occasioning actual bodily harm. The trial judge told the jury that the belief of the defendant that force was needed had to be based on reasonable grounds. Williams appealed to the Court of Appeal.

Issue

Whether a defendant who uses force on the basis of a mistaken belief that he is preventing a crime or defending another is entitled to be judged on the facts as he honestly believed them to be, or only on facts that he reasonably believed.

Held

Appeal allowed and the conviction quashed. The jury should have been directed to consider whether the defendant honestly believed that force was necessary, and not whether the belief was reasonable.

Ratio

• Where a defendant uses force under a mistaken belief in facts which would, if true, justify force in self-defence or in the prevention of crime, he is to be judged according to his genuine belief, whether or not the belief was reasonable. The reasonableness of the belief is relevant only to whether it was genuinely held.

The judgments

Key reasoning

• Assault and battery require an intention to apply unlawful force, and a defendant who believes that his conduct is lawful because of the facts as he understands them lacks that intention.
• The analogy with rape and the authorities on mistaken belief in consent show that an honest belief negates mens rea whether or not it was based on reasonable grounds.
• The reasonableness of the belief is a matter which a jury may take into account when deciding whether the defendant truly held it, but it is not a condition of the defence.

Where it fits in the module

In the Incapacity and General Defences topic the case sets the subjective test of mistaken belief in self-defence and the general rule that mistakes need not be reasonable. The module debates whether the defence should depend on honest belief or whether reasonableness should be required in the public interest. The relationship with intoxicated mistakes, which later Court of Appeal decisions of 1987 and 2005 have held cannot found the defence, and the later statutory version in section 76 of the 2008 Act, falls to be considered.

Criticisms

• A purely subjective test lets a defendant rely on an irrational or unreasonable mistake, which can be unfair to victims and might be thought to deprive the defence of any link to reasonable conduct.
• The rule rests on an analogy with other offences based on the mental element and does not engage with the policy of the justification, in particular whether force used in error is justified or only excused.
• The decision leaves the relationship between honesty and reasonableness uncertain, and the treatment of reasonableness as evidence only is difficult for juries to apply.