Insanity and M’Naghten’s Test Flashcards
Introduction - Historical
The M’Naghten rules were a reaction to the acquittal of Daniel
McNaughton, who was charged with the attempted assassination of the
British Prime Minister, Robert Peel, in 1843. M’Naghten fired a pistol at the
back of Peel’s secretary, Edward Drummond, who died five days later.
The House of Lords asked a panel of judges, a series of hypothetical
questions about the defence of insanity. The principles expounded by this
panel have come to be known as the M’Naghten Rules. The rules so
formulated as M’Naghten’s Case24 have been a standard test for criminal
liability in relation to mentally disordered defendants in common law
jurisdictions ever since, with some minor adjustments.
M’Naghten’s Rules
The M’Naghten’s rules are frequently used to establish whether or not a
defendant is insane. It is based on the person’s ability to think rationally, so
that if a person is insane they were acting under such a defect of reason from
a disease of the mind that they did not know:
- the nature and quality of their actions, or
- that what they were doing was wrong.
Disease of the mind
The Courts have not attempted a precise or comprehensive definition of the
term “a disease of the mind”. It has been said to be “a term which defies
precise definition and which can comprehend mental derangement in the
widest sense”
In R v Warren25, the defendant was the driver of a motor vehicle who killed
two people.
The Court accepted that at the time of the crash involving the motor vehicle
that led to the deaths, the defendant’s mental condition was such that he was
so deluded he would not have understood he was driving a car dangerously.
The defendant’s view was that he was essentially no longer in a car but, with
doors locked and driving at high speed, in a time capsule. His perception was
such that he did not understand he was driving a car dangerously, so
therefore did not understand the nature and quality of his act.
The Court in this matter found that a manic episode of bipolar affective
disorder with psychotic features was a disease of the mind for the purposes
of s 23(2).
Physical damage not necessary
A condition may be a disease of the mind whether or not there is any damage
to the brain or other physical organ, the law being concerned with the
“mind” — the mental faculties of reason, memory, and understanding; and
the disorder may be permanent or temporary, of short or long duration,
curable or incurable.
The Court in R v Cottle26 accepted that epilepsy, although physical, could
amount to a disease of the mind.
Temporary mental disorder not included
“Disease of the mind” does not include a temporary mental disorder caused
by some factor external to the defendant, such as a blow on the head, the
absorption of drugs, alcohol, or an anaesthetic, or hypnotism.
A question of law
In practice, medical witnesses are permitted to say whether they regard a
disorder as a “disease of the mind”, as well as testifying as to the causes and
symptoms of the condition diagnosed, but such a classification by medical
witnesses is not final, and whether the particular condition is a disease of the
mind is a question of law for the Judge.
Disease of the mind is not a medical question but a legal one.
Nature and quality of the act
Under s23(2)(a) the defence is established if mental disease rendered the
defendant “incapable of understanding the nature and quality of the act or
omission”.
The words “nature and quality” are to be read as a composite expression
dealing only with the physical character of the conduct, and not as separate
terms distinguishing its physical and moral aspects.
R v Codere27 provides a succinct definition of what constitutes the nature
and quality of an act.
R v Codere (1916) 12 Cr App R 21 (CA)
The nature and quality of the act means the physical character of the act. The
phrase does not involve any consideration of the accused’s moral perception nor
his knowledge of the moral quality of the act. Thus a person who is so deluded
that he cuts a woman’s throat believing that he is cutting a loaf of bread would not
know the nature and quality of his act.
Morally wrong
The test is that the defendant knew that their acts were morally wrong – they
do not need to know that they were legally wrong. If someone cannot
understand that their act is morally wrong, then they lack rational
understanding.
In other words, they may acknowledge the result of society’s reasoning –
that their actions are morally wrong – but they are unable to go through the
reasoning process themselves.
Consequences
Under s24 and s25 of the Criminal Procedure (Mentally Impaired Persons)
Act 2003, someone found unfit to stand trial or acquitted on account of his
or her insanity may be detained as a special patient or special care recipient.
Court to decide on detention, release or alternative order
Where the person is found unfit to stand trial or acquitted on account of his
or her insanity, the court, having considered the circumstances of the case
and the evidence of one or more health assessors may determine such an
order is not necessary and order the immediate release of the person.
The court must decide whether to detain, release or apply alternative orders
to the person. In reaching its decision, the court must consider all the
circumstances, and may hear further medical evidence concerning whether
release or alternative measures are safe in the public interest.
Public interest may override other factors
In the case of a serious homicide the public interest to detain the offender
may override other factors. Under s31 CP(MIP) Act, the Attorney-General
may direct that the defendant be held as a patient or a care recipient.
