Criminal Law (2014): Mens Rea

Compare and contrast the defences of insanity and automatism.

General remarks
Most candidates know the McNaghten rules and know what automatism means. This question tests your understanding of these defences. Only if you know what they have in common and what differentiates them do you manifest such understanding.

Common errors
Failing to compare and contrast the two defences.

A good answer to this question would…
include the following indicative elements.

• Description and exposition of the defences, including definitions

Comparison

• Both are mental condition defences.
• Both affect capacity.
• Both operate as excuses.
• Both require support of medical evidence.
• Automatism (always) and insanity (usually) both require the defendant’s mental condition to affect D’s understanding of the nature and quality of his act.
• Both negate mens rea and actus reus.

Contrast

• Insanity, unlike automatism, requires a disease of the mind. Reference should be made to the external/internal dichotomy created by Kemp. 
• Automatism is an absolute defence. Insanity is a qualified defence.
• Prior fault operates for automatism. Not for insanity.
• Burden of proof differences.

Poor answers to this question…
tended to be light on case law, did not define one or other of the defences accurately and did not attempt to show their similarities and points of difference.

Student extract
The defences of Insanity and automatism are both failure of proof defences used to negate or prove that a particular element of a crime is missing to negate/contend liability. The defences themselves while seemingly at the opposite ends of a spectrum from one another do in fact have similarities. This essay will discuss scenarios courts have considered the scope of each defence and the rules that govern them.

Let us first look at the defence of Automatism. Automatism is defined in dawson. It is involuntary conduct where the defendant is effectively unconscious when doing the act the Act is not being done by them however the act is happening to them. This basically means one who is in a state of automatism is unaware that they are doing such actions. In Hill v Baxter it was equated to a swarm of bees or a blow from a stone.

The defence of automatism is very useful in the sense that it can in fact be used to negate the Actus Reus of a crime, they can use it to say they did not commit the act as explained before it “happened to them”. By being able to negate the Actus reus of a crime automatism unlike insanity is open to be a defence even for strict liability offences there are offences where by the proof of Mens Rea which is what insanity negates is not required on the Actus Reus or action itself is what is legally wrong eg. Dangerous driving (there is no need to prove that they intended to drive dangerous or hurt someone, the act of driving dangerously exposes them to criminal liability in itself).

Comment on extract
This extract shows a method and understanding. It begins, as it should do, with a brief introduction which sets the scene for the future discussion. It gives a good definition of automatism and explains and illustrates how it can be used to negate the actus reus of a crime and thus can be used as a defence even to strict liability crimes. The rest of the answer follows this orderly and well reasoned path and ended up with a very good mark.