14. General defences

Self-defence

No duty to retreat: In Kargbo v Reginam the Court of Appeal held that a person defending himself need not retreat and may resist until out of danger.

Imminence: The threat must be immediate. In Yankor v Reginam (WACA), killing a man believed to be a cannibal who would later eat the accused was a pre-emptive strike, not self-defence.

Burden: Once self-defence is raised, the prosecution must disprove it (Sumana v R).

Reasonable force: The force used must be reasonable in the circumstances as the accused honestly believed them to be.

Necessity and duress

Necessity: Not a defence to murder (R v Dudley and Stephens).

Duress: Threats of death or serious injury may excuse some crimes, but not murder.

Intoxication

DPP v Beard: Drunkenness that causes insanity is a defence like other insanity; drunkenness that prevents the formation of a specific intent may reduce murder to manslaughter. Wreh (or Dee) v Regem (WACA) found a misdirection where the judge did not tell the jury that intoxication could reduce murder to manslaughter.

Insanity

M'Naghten Rules: The accused must prove that, from a disease of the mind, he did not know the nature and quality of his act or that it was wrong. Yankor v Reginam confirmed these rules apply in Sierra Leone.

Burden: On the accused, on the balance of probabilities; medical evidence is not essential.

Directions: A judge should not direct the jury on insanity where it is neither pleaded nor supported by evidence (Amara v Reginam; Feika v Reginam).

Consent

Limits: Consent is generally no defence to the intentional infliction of actual bodily harm, subject to recognised exceptions such as lawful sports.