Mental capacity defences

Insanity

also known as sane automatism

available for all offences

rules are made my M’naughten rules 1843

First stage of insanity

There must be a defect of reason

This means it dependence inability to use the powers of reason, and it must be more than absentmindedness-provided by Clark

Sullivan provides it can be a temporary deprivation of power

Second stage of insanity

The defect of reason must arise from a disease of the mind

The disease of the mind must be caused by an internal factor rather than an external factor

The case of Kemp provides that it can be a physical factor, not just a mental factor

Hennessy – diabetes

Bratty – Epilepsy

Burgess-Sleepwalking

Quick – the internal factor must not be affected by an external factor

The internal disease must affect the ordinary mental faculties

Third stage of insanity

As a result of the disease of the mind, the defendant must not know either the nature and quality of their actions or what they did was illegal

Automatism

Also known as sane Automatism

Available for all offences

Leads to an acquittal

First stage of automatism

Defendant must show there was an involuntary act

This means the act was done by the muscles and without the control of the mind

Bratty– Defendant is not aware of what he is doing

There must be a total lack of awareness, it cannot be partially automatic as seen AG’s ref no.2 Of 1992

Second stage of automatism

The involuntary act must be due to an external factor provided by quick

The defence cannot be self induced for example alcohol

If it is self induced then whether they can use the defence depends on whether it is a specific intent crime or a basic intent crime

If it is a specific intent crime, then the defendant can use the defence

If it is a basic intent crime and the defendant did not manage their health or was voluntarily intoxicated then he could not use the defence

If the defendant was unaware of the impact of the external factor then he can use the defence even if it is a specific intent crime or basic intent crime

Voluntary intoxication

it’s a defence specific intent crimes, not basic intent crimes provided by Majeski

Allen– If the defendant Consumes drugs or alcohol and doesn’t know the strength of them then that is voluntary intoxication

Richard and Irwinson– It can be used as a defence for basic intent crimes if the defendant would not have noticed the risk even if He was sober

Kingston – it can be used as a defence when the defendant could not form a MR

Lipman – provides it is only a partial defence so the defendant would be guilty of less crime however there is no fallback crime for property offences

Gallagher provides if the defendant drinks for Dutch courage the defence cannot be used

O’Grady Provides if the defendant makes a genuine mistake because they are intoxicated the defence cannot be used

Involuntary intoxication

Kingston- does not know he is consuming drugs or alcohol

Bailey - taking prescribed drugs unpredictable reaction

Hardie- taking non-prescribed drugs there is an unexpected reaction

Allen- if the did not know the strength of drink this is not involuntary

Majewski – it is used for specific intent crimes and basic intent crimes

Kingston – it is used when the defendant cannot form an MR