• In the case of Johnson [2007] EWCA Crim 1978, it was established that where the wrongdoer knew his act was illegal meant the defence of insanity under the M’Naghten Rules cannot apply. Being unaware that it was morally wrong did not matter.

Facts of Johnson [2007] EWCA Crim 1978

  • D suffered from schizophrenia
  • Whilst in a schizophrenic episode, he stabbed people
  • At the trial, the two psychiatrists agreed that the D was aware of the nature of his acts and knew they were illegal, however one noted he may not have been aware that he was committing a morally wrong act
  • Despite this, the High Court judge ruled against the defence of insanity applying, holding that the D’s knowledge that his act was legally wrong meant the defence could not apply
  • The D appealed, arguing that the ruling handed by the High Court was incorrect and the defence of insanity could be raised

Issues in Johnson [2007] EWCA Crim 1978

  • Under the M’Naghten Rules, did the defence of insanity apply in situations where the D had knowledge that the act was against the law, but was not aware it was morally wrong?
  • In other words, did the M’Naghten Rules apply to the wrongdoer being unaware as to moral wrongs or illegality?

Held by the Court of Appeal

Appeal dismissed. The M’Naghten Rules applied to one’s knowledge of illegality, not morality. Therefore, the defence of insanity could not be raised.

Lord Justice Latham

The defence of insanity can only be put forward “on the basis that there is material which could satisfy the jury on the balance of probabilities that the defence is available in accordance with the Rules as understood.” [13]

The judges accepted the observations of the High Court of Australia in the case of R v Stapleton (1952) “indicating the difficulties and internal inconsistencies which can arise from the application of the M’Naghten Rules” [21]

The Court of Appeal cited the Lord Chief Justice in R v Windle [1952] to note what the definition of ‘wrong’ under the M’Naghten rules to be:

  • “contrary to law and does not have some vague meaning which may vary according to the opinion of different persons whether a particular act might or might not be justified.” [21]
  • “This statement of the law is unequivocal and has been, so far as we are aware, been doubted since then in this court.” [22]

Despite acknowledging the difficulties that may arise, the Court of Appeal believed this was not the level the debate could properly take place, thus dismissing the appeal [24]