11.2.2 Fitness, responsibility, diminished responsibility, amnesia and automatism

Two questions, two timeframes

• Fitness to plead asks whether the defendant can take part in the trial now. Criminal responsibility asks about their mental state when the alleged act happened.

• Neither answer decides the other, and unfitness to plead is not a defence.

Criminal responsibility

A criminal offence has two elements. Criminal responsibility is established only when both are proved.

• Doli incapax: a child under 10 in England and Wales is conclusively presumed incapable of crime and cannot be convicted of any offence (Children and Young Persons Act 1933, as amended).

• Scotland's minimum age of criminal responsibility is now 12.

• The United Nations Committee on the Rights of the Child (General Comment No. 24, 2019) urges states to set the minimum age at 14 or above.

The insanity defence

• The M'Naghten rules test insanity and criminal responsibility for past conduct: a defect of reason, from disease of the mind, so that the defendant did not know the nature and quality of the act or that it was wrong.

• "Wrong" means legally wrong, so knowing an act is illegal while believing it morally justified does not satisfy the test.

• Disease of the mind is a legal category: epilepsy, hyperglycaemia, sleepwalking and arteriosclerosis have qualified, but a psychiatric diagnosis alone is not enough.

• The defence proves insanity on the balance of probabilities, and success brings the special verdict of not guilty by reason of insanity.

Intoxication

• Voluntary intoxication cannot found insanity, is not automatism of either kind, and gives no defence to a basic intent offence, because its cause is self-induced and external.

• Mania a potu is another name for pathological intoxication: a disproportionate violent reaction to little alcohol, with later amnesia.

Defences to murder

• Voluntary manslaughter is a killing with the intent for murder, reduced by a partial defence.

• Involuntary manslaughter is a killing without intent to kill or cause grievous bodily harm, arising from an unlawful dangerous act or gross negligence.

• Voluntary culpable homicide in Scots law is a killing with the mental element for murder, reduced by a recognised partial plea such as diminished responsibility.

Diminished responsibility

• Diminished responsibility is a partial defence available only to murder, because it exists to escape the mandatory life sentence.

• Section 2 of the Homicide Act 1957, amended by section 52 of the Coroners and Justice Act 2009, requires all four of these conditions:

  1. The defendant had an abnormality of mental functioning.

  2. A recognised medical condition caused it.

  3. It substantially impaired their ability to understand their conduct, form a rational judgement or exercise self-control.

  4. It caused or significantly contributed to the killing.

• Substantial means an impairment of real importance or weight, not merely more than trivial (R v Golds, 2016).

• Any recognised medical condition present at the time of the killing can support it, including a non-psychotic depressive episode.

• Voluntary intoxication, amnesia for the act or a past diagnosis alone cannot support it.

• A psychotic parent who kills their child knowing it was unlawful fails M'Naghten but readily meets the abnormality of mental functioning test, so diminished responsibility is the likely defence.

Infanticide

• The Infanticide Act 1938 applies only to the woman who gave birth to the child, where the child is under 12 months and the effects of birth or lactation disturbed the balance of her mind.

Automatism

• Automatism is wholly involuntary conduct, so there is no voluntary guilty act; impaired control or intense anger is not enough (Bratty v Attorney General for Northern Ireland, 1963).

• Self-induction, foreseeability and voluntary intoxication can stop a defendant relying on automatism.

• An electroencephalogram (EEG) cannot by itself show loss of control during the offence, and amnesia alone does not establish automatism.

Sleepwalking

• Genuine sleepwalking is an arousal disorder from slow-wave sleep, so it happens early in the night, within about 15 to 120 minutes of sleep onset.

• The sleepwalker is confused when roused, has amnesia afterwards and shows no planning or concealment.

• In England and Wales an offence committed while sleepwalking is insane automatism, because the cause is internal.

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Amnesia for the offence

• Amnesia alone establishes neither unfitness, automatism nor diminished responsibility, and it is not a bar to trial.

• Genuine amnesia for a violent offence is associated with unplanned domestic homicide: killing a spouse or lover in overwhelming emotional arousal such as rage.

• The mechanism is psychogenic (dissociative) amnesia, with a mismatch between the mental state at encoding and at retrieval.

• Inconsistency in the account does not by itself prove malingering.

Fitness to plead

The Pritchard criteria

• Fitness is judged on present functional ability to take part in the trial, not on diagnosis or history.

• R v Pritchard (1836) set out the test, and its defendant was deaf and mute rather than mentally ill; R v M (John) (2003) restated it.

The test has six abilities, and losing any one makes the defendant unfit:

1. They can understand the charge.

2. They can decide on a plea.

3. They can challenge jurors.

4. They can instruct their solicitor and counsel.

5. They can follow the proceedings.

6. They can give evidence.

• Memory for the offence is not a Pritchard ability, so amnesia with intact present cognition does not make a defendant unfit (R v Podola).

• A present cognitive impairment, such as moderate dementia with poor retention, can make a defendant unfit because it stops them following the proceedings.

• Psychosis does not automatically make a defendant unfit; what matters is how delusions or disorganisation affect real participation.

• The MacCAT-FP is the England and Wales adaptation of the MacArthur competence tool for assessing fitness to plead.

Procedure and outcome

• The judge decides fitness on evidence from at least two registered medical practitioners, one approved under section 12.

• After a finding of unfitness the ordinary trial stops, and a jury holds a trial of the facts (section 4A, Criminal Procedure (Insanity) Act 1964).

• The jury decides only whether the defendant did the act charged, without examining intent or guilt.

• There is no conviction or punishment; disposals follow, including hospital orders, supervision and absolute discharge.