General Defences in Criminal Law

General Defences in Criminal Law

General defences are available across a range of criminal offences (unlike partial defences such as diminished responsibility, which apply only to murder). If successfully raised, they result in a complete acquittal.

Self-Defence

Self-defence is available under common law (defence of self or others) and s.3 Criminal Law Act 1967 (use of reasonable force to prevent crime or effect lawful arrest). The Crime and Courts Act 2013 amended the law for householders.

Elements

The jury must consider two questions:

1. Was the use of force necessary?

• D must have honestly believed that force was necessary — even if that belief was mistaken, provided it was genuinely held (R v Williams (Gladstone) [1987]; R v Beckford [1988])
• D is judged on the facts as they honestly believed them to be — s.76 Criminal Justice and Immigration Act 2008 codified this
• However, a mistake induced by voluntary intoxication cannot be relied upon — R v O'Grady [1987]; s.76(5) CJIA 2008
• D is not required to retreat before using force, although failure to retreat may be evidence that force was not necessary — s.76(6A)
• Pre-emptive strikes are permitted — D need not wait to be hit first (R v Beckford [1988]: "a person about to be attacked does not have to wait for his assailant to strike the first blow")

2. Was the force used reasonable (proportionate)?

• The force must be reasonable in the circumstances as D believed them to be — s.76(3)
• The jury should consider that D may have been acting in the heat of the moment and cannot be expected to "weigh to a nicety the exact measure of any necessary action" — R v Palmer [1971]; s.76(7)
• R v Clegg [1995] — a soldier shot a joyrider in a stolen car with the last of several bullets as the car was driving away. The force was held excessive (the threat had passed)
• R v Martin (Anthony) [2002] — a farmer shot two burglars, killing one. His force was excessive for ordinary self-defence, but diminished responsibility was accepted on appeal

Householder cases (s.76(5A)–(5D) CJIA 2008, added by Crime and Courts Act 2013):

• Where D is a householder acting against a trespasser, the force is unreasonable only if it was grossly disproportionate
• This gives householders greater latitude than the general rule of reasonable force
• Force that is disproportionate (but not grossly so) may still be reasonable for householders

Effect

Self-defence, if successful, is a complete defence resulting in acquittal.

Intoxication

Intoxication is not a true defence — it may, in certain circumstances, prevent the prosecution from proving mens rea.

Voluntary Intoxication

Where D chose to consume alcohol or drugs:

• It is a defence to specific intent offences only — DPP v Majewski [1977]
• If D was so intoxicated that they could not form the required intent, they are acquitted of the specific intent offence but may be convicted of a lesser basic intent offence (e.g. acquitted of murder but convicted of manslaughter; acquitted of s.18 GBH but convicted of s.20)
• It is no defence to basic intent offences — becoming voluntarily intoxicated is itself considered reckless (Majewski)

Specific intent offences	Basic intent offences
Murder	Manslaughter
s.18 GBH with intent	s.20 GBH/wounding
Theft	Assault, battery, s.47 ABH
Robbery	Criminal damage (basic)
Burglary (s.9(1)(a))	Burglary (s.9(1)(b))
Fraud

"Dutch courage" — Attorney General for Northern Ireland v Gallagher [1963]: if D gets drunk deliberately to gain courage to commit an offence, intoxication provides no defence, even to a specific intent offence.

Involuntary Intoxication

Where D did not know they were consuming an intoxicant (e.g. spiked drink):

• It is a defence to any offence if D lacked the mens rea — R v Kingston [1995]: however, if D still formed the mens rea despite being involuntarily intoxicated, the defence fails. In Kingston, D's drink was spiked and he committed an indecent assault on a boy — he was convicted because he still formed the intent, even though his inhibitions were lowered
• Involuntary intoxication does not provide a defence merely because D would not have committed the offence when sober

Intoxicated Mistakes

• A drunken mistake as to the need for self-defence cannot be relied upon — R v O'Grady [1987]
• A drunken belief in consent (e.g. to sexual activity) cannot be relied upon — R v Fotheringham [1989]
• Exception: a drunken belief in lawful excuse for criminal damage can be relied upon — Jaggard v Dickinson [1981] (see s.5(2)(a) Criminal Damage Act 1971)

Insanity (M'Naghten Rules)

The M'Naghten Rules [1843] provide that D is not guilty by reason of insanity if, at the time of the act:

1. D was suffering from a defect of reason

2. Caused by a disease of the mind

3. Such that D either:

• Did not know the nature and quality of the act, or
• Did not know that what they were doing was wrong (legally wrong — R v Windle [1952])

"Disease of the mind" has been interpreted broadly:

• R v Kemp [1957] — arteriosclerosis (hardened arteries) affecting the brain
• R v Sullivan [1984] — epilepsy
• R v Hennessy [1989] — hyperglycaemia caused by diabetes (failure to take insulin — an internal cause)
• R v Burgess [1991] — sleepwalking (an internal cause, therefore insanity, not automatism)

Verdict: "Not guilty by reason of insanity" — under the Criminal Procedure (Insanity and Unfitness to Plead) Act 1991 (as amended by the Domestic Violence, Crime and Victims Act 2004), the court may impose: a hospital order, a supervision order, or an absolute discharge. For murder, a hospital order is mandatory.

The burden of proof is on the defence (balance of probabilities) — M'Naghten [1843]. This is one of the rare exceptions to Woolmington v DPP [1935].

Automatism

Automatism is a defence where D's actions were involuntary — D had no control over their bodily movements. It is a complete defence resulting in acquittal.

Requirements:

• A total loss of voluntary control — Attorney General's Reference (No. 2 of 1992) [1994]: "reduced or imperfect control" is insufficient; the loss must be total
• Caused by an external factor (not a disease of the mind — otherwise it is insanity):
• R v Quick [1973] — hypoglycaemia caused by taking insulin (an external factor) = automatism
• R v Hennessy [1989] — hyperglycaemia caused by not taking insulin (an internal condition) = insanity
• Other external causes: a blow to the head, an attack of bees, sneezing, reflex actions

Self-induced automatism:

• If D's automatism was caused by their own fault (e.g. failing to eat after taking insulin), it is no defence to basic intent offences (R v Bailey [1983])
• Voluntary intoxication causing automatism is governed by the intoxication rules (Majewski)

Duress

Duress is a defence where D committed the offence because they were threatened with death or serious physical injury.

Duress by Threats

*Requirements (from R v Graham [1982], approved by R v Hasan [2005]):*

1. D reasonably believed they (or a close family member/person for whom they were responsible) would be killed or seriously injured if they did not commit the offence

2. A sober person of reasonable firmness, sharing D's characteristics, would have responded in the same way

3. The threat must be of death or serious physical harm — threats to property or reputation are insufficient (R v Valderrama-Vega [1985] — financial pressure and threats of exposure could be considered alongside death threats)

4. The threat must be imminent and operative — D must have had no reasonable opportunity to escape or seek police protection (R v Hasan [2005])

5. D must not have voluntarily associated with criminals, foreseeing that they might be compelled to commit offences — R v Hasan [2005] significantly narrowed the defence

Duress is NOT available for:

• Murder — R v Howe [1987] (House of Lords — overruling R v Lynch [1975])
• Attempted murder — R v Gotts [1992]

Duress of Circumstances

A variant of duress where the threat arises from circumstances rather than direct threats. Recognised in R v Willer [1986] (D drove on a pavement to escape a gang) and R v Conway [1989] (D drove recklessly believing a passenger was about to be attacked).

The same requirements apply as for duress by threats. The defence was applied in R v Martin [1989] — D drove while disqualified because his wife (who had suicidal tendencies) threatened to kill herself if he did not drive her son to work.

Consent

Consent is a defence to assault and battery but generally not to offences causing ABH or above — Attorney General's Reference (No. 6 of 1980) [1981]; R v Brown [1994].

Exceptions where consent is valid even for ABH/GBH:

• Properly conducted sports — R v Barnes [2005]: legitimate sporting contact is not criminal; only conduct outside the rules and spirit of the game loses the protection of consent
• Reasonable surgical procedures — medical treatment with informed consent
• Tattooing and body piercing — R v Wilson [1997]: branding was compared to tattooing
• Horseplay — R v Jones [1986]; R v Aitken [1992]

R v Brown [1994] — consensual sadomasochistic acts causing ABH: the House of Lords held (3:2) that consent was no defence. The minority argued that consenting adults should be free to act as they wish in private. The ECtHR upheld the conviction in Laskey, Jaggard and Brown v UK [1997].

Informed consent: the victim must have given true consent. Consent obtained by fraud as to the nature or quality of the act is invalid — R v Tabassum [2000] (women consented to breast examinations believing D was medically qualified). Fraud as to identity also vitiates consent — R v Richardson [1999]. However, deception about other matters (e.g. HIV status) does not negate consent to the physical act itself, though it may negate consent to the risk — R v Dica [2004].

Key Exam Points

• Self-defence: apply the two-stage test (necessity + proportionality) and note the householder extension
• Intoxication: always classify the offence as specific or basic intent before applying Majewski
• Insanity vs automatism: the key distinction is internal vs external cause
• Duress: apply the Graham/Hasan test methodically and remember it is unavailable for murder
• Consent: apply the Brown general rule and then consider the recognised exceptions
• Evaluate whether the law on intoxication is fair and whether insanity should be reformed (the Law Commission has proposed an updated defence)