Insanity/Automatism
a. Definition of Insanity
- Pleading insanity means that D was incapable of paying attention to the law’s guidance
- Based on Criminal Procedure (Insanity) Act 1964,
- If D successfully pleads insanity, court gives a special verdict of “not guilty by reason of insanity”
- Heavy stigma associated with label of insanity
- Legal definition is from M’Naghten Rules [distinct from medical definition]
b. M’Naghten Rules
- M’Naghten [an incident, not a case]
o Rebuttable presumption of sanity
o Rebutted if D has a ‘disease of the mind’
o Which brings about a ‘defect of reason’
o That results in D not knowing the nature and quality of his act, or that what he was doing
was legally wrong
c. Presumption of Sanity
- Burden of proof lies on D to show insanity [R v Sullivan]
- Standard of proof: Prove that on a balance of probability, it is more likely than not that D is
insane [R v Carr-Briant]
R v Carr-Briant
Do not have to prove beyond reasonable doubt
D just has to prove that it is more likely than not that he is insane - 'balance of probabilities'
d. Disease of the Mind
- Any internal factor will suffice
- Eg. Narrowing of arteries, Epilepsy, Sleepwalking, Diabetes
- For diabetic cases – if D takes insulin but then does not eat and commits a crime while in diabetic
shock, the factor is the insulin, and is thus considered as an EXTERNAL factor defence of
automatism
R v Kemp
Held that narrowing of arteries is an internal factor disease of the mind
R v Sullivan
Held that epilepsy [affects brain, causes seizure] is a disease of the mind
R v Burgess
Held that sleepwalking is an internal factor disease of the mind
a. Definition of Insanity
- Pleading insanity means that D was incapable of paying attention to the law’s guidance
- Based on Criminal Procedure (Insanity) Act 1964,
- If D successfully pleads insanity, court gives a special verdict of “not guilty by reason of insanity”
- Heavy stigma associated with label of insanity
- Legal definition is from M’Naghten Rules [distinct from medical definition]
b. M’Naghten Rules
- M’Naghten [an incident, not a case]
o Rebuttable presumption of sanity
o Rebutted if D has a ‘disease of the mind’
o Which brings about a ‘defect of reason’
o That results in D not knowing the nature and quality of his act, or that what he was doing
was legally wrong
c. Presumption of Sanity
- Burden of proof lies on D to show insanity [R v Sullivan]
- Standard of proof: Prove that on a balance of probability, it is more likely than not that D is
insane [R v Carr-Briant]
R v Carr-Briant
Do not have to prove beyond reasonable doubt
D just has to prove that it is more likely than not that he is insane - 'balance of probabilities'
d. Disease of the Mind
- Any internal factor will suffice
- Eg. Narrowing of arteries, Epilepsy, Sleepwalking, Diabetes
- For diabetic cases – if D takes insulin but then does not eat and commits a crime while in diabetic
shock, the factor is the insulin, and is thus considered as an EXTERNAL factor defence of
automatism
R v Kemp
Held that narrowing of arteries is an internal factor disease of the mind
R v Sullivan
Held that epilepsy [affects brain, causes seizure] is a disease of the mind
R v Burgess
Held that sleepwalking is an internal factor disease of the mind
