Insanity Flashcards
What type of defence is insanity?
Insanity is a general defence available to all criminal offences. It is a common law defence, meaning it has developed through case law rather than statute.
Is insanity a complete defence?
No. If successful, insanity results in a special verdict of ‘Not guilty by reason of insanity’ under the Criminal Procedure (Insanity) Act 1964, not a complete acquittal.
What are the sentencing options for a successful insanity defence?
The court has a range of disposals, including:
• Hospital order (potentially for an unlimited period)
• Supervision order
• Absolute discharge
This range allows flexibility depending on the severity and risk associated with the defendant’s condition.
When must the defendant be insane for the defence to apply?
The defendant must have been insane at the time of committing the offence.
What case defines the legal test for insanity?
The test comes from M’Naghten [1843], which set out three elements that must be proven.
What is the first element of the M’Naghten Rules?
- Defect of reason – The defendant must be deprived of the power of reasoning at the time of the offence.
Which case clarifies what counts as a defect of reason?
Bratty [1963] – The defect must affect the cognitive faculties of memory, reason, or understanding.
Which case clarifies what does not count as a defect of reason?
Clarke [1972] – Temporary absent-mindedness, confusion, or failing to use powers of reasoning (rather than being deprived of them) does not constitute insanity.
What is the second element of the M’Naghten Rules?
- The defect of reason must be caused by a disease of the mind.
What does ‘disease of the mind’ mean in legal terms?
It is a legal concept, not a medical one. It refers to any mental or physical condition that causes a malfunction of the mind and is internal in origin.
What case confirms that ‘disease of the mind’ can be a physical condition?
Kemp [1957] – A hardening of the arteries causing loss of consciousness was considered a disease of the mind.
What case confirms that the source of the condition is irrelevant as long as it’s internal?
Sullivan [1984] – Held that epilepsy, an internal condition affecting the mind, was sufficient even though the mental state was temporary.
What if the mental impairment is caused by a voluntarily taken intoxicant?
Coley [2013] – If D voluntarily takes drugs and this causes a temporary psychotic state, the defence of insanity is not available. It must be internal.
What case shows that hyperglycemia (high blood sugar) from diabetes is internal?
Hennessey [1989] – D was in a hyperglycemic state caused by failure to take insulin. This was internal, so insanity was appropriate.
What case shows that hypoglycemia (low blood sugar) from insulin is external?
Quick [1973] – D took insulin and failed to eat, causing a hypoglycemic state. This was externally induced, so the correct defence was automatism, not insanity.
What is the third element of the M’Naghten Rules?
- As a result of the disease of the mind, the defendant:
• Did not know the nature and quality of the act, OR
• Did not know that what they were doing was wrong
Only one of these needs to be proven.
What does ‘not knowing the nature and quality’ mean?
The defendant was unaware of what they were physically doing — e.g. they thought they were chopping wood but were actually harming someone.
What does ‘not knowing the act was wrong’ mean in law?
The defendant must not know that what they were doing was legally wrong, not just morally wrong.
What case confirmed that ‘wrong’ means legally wrong?
Windle [1952] – D gave his wife a fatal dose of aspirin and said ‘I suppose they’ll hang me for this.’ He knew it was legally wrong, so the defence failed.
What case supports the use of insanity where D did not know the act was wrong due to psychosis?
Oye [2013] – D was suffering from a psychotic episode and believed he was fighting evil spirits. He did not understand what he was doing was wrong. Defence succeeded.
