9 November, 2007


Filed under: A2-Level,additional reading,Fatal Offences — legaleasy @ 9:44 pm

W/E 9th November 2007

This week we started to look at the six defences that may be available to a defendant. Remember, some defences can be used for any offence, other defences can only be used for certain offences.

Unlike the special defences, if one of the six defences are successful then the defendant is usually acquitted (a special defence only lowers a murder charge to one of voluntary manslaughter).

The exception to this is the defence of insanity. In this instance a defendant is guilty by reason of insanity. This allows a judge to make a mental health order to detain the defendant in hospital.

The six defences are: insanity, automatism, intoxication, mistake, self defence and consent.


The rules on insanity are from the case of M’Naughten (1843) where it was stated that for the defendant to prove the defence of insanity then at the time of committing the act the defendant was;

“labouring under such a defect of reason, from disease of the mind, as not to know the nature of the and quality of the act he was doing, or if he did know it, that he did not know what he was doing what was wrong.”

There are therefore 3 elements to this – (1) a defect of mind, (2) caused by a disease of the mind, and (3) this causes the defendant not to know what they are doing.

Refer to the cases of Clarke (1972), Sullivan (1983) and Windle (1952).


Bratty v AG for N.Ireland (1961) defined automatism as;

“an act done by the muscles without any control by the mind, such as a spasm, a reflex action or a convulsion; or an act done by a person who is not conscious of what he is doing such as an act done whilst suffering from concussion or whilst sleepwalking.”

This covers both insane automatism – which is a disease of the mind and therefore comes under M’Naughten; and non-insane automatism which covers situations such as;

  • an attack by a swarm of bees;
  • sneezing;
  • a blow to the head;
  • the effect of a drug.

Please refer to the cases of Bailey (1983) and Hardie (1984). Watch out though – the law applies differently depending on whether it is a crime of specific or basic intent.


This covers alcohol, drugs or any other intoxicating substance (including prescription drugs).

It does not provide a defence in the same way as insanity or automatism, rather it is relevant as to whether the defendant has the required mens rea for the offence – see my comments on specific and basic intent above. If he does not have the required mens rea, then he may be not guilty.

The relevant factors are;

  1. is it a crime of specific or basic intent.
  2. was the intoxication voluntary (a reckless course of conduct – Majewski (1977)) or involuntary.

Please refer to the cases of Majewski (1977) and Kingston (1994) for further exploration of these two points.


The mistake must be about fact. It must be genuine, and even if unreasonable will be a defence – see Williams (1987).

If because of a genuine mistake a defendant uses force, that force must be reasonable otherwise the defendant does not have a defence.

A defendant can make a drunken mistake which means he doesn’t have the required mens rea for an offence. However, if as a result of being drunk a defendant is mistaken in the amount of force required for self defence then he does not have a defence. See O’Grady (1987) and Hatton (2005). This applies whether the crime is one of specific or basic intent. Contrast this with the decision in Richardson & Irwin (1999).

Additional Reading

As always please refer to the books in the Resource Centre for additional materials on this subject. Please also look at your revision guides.

Please forward to me suggestions for revision for the January Exam as soon as possible.


Leave a Comment »

No comments yet.

RSS feed for comments on this post. TrackBack URI

Leave a Reply

Please log in using one of these methods to post your comment: Logo

You are commenting using your account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

Blog at

%d bloggers like this: