Crimes Act 1961 Westlaw Lexis Nexis
Starting points …
Insanity is an available defence for all criminal charges. The points below address only some of the many issues which have arisen.
Garrow & Turkington’s Criminal Law in New Zealand and Adams on Criminal Law both contain comprehensive sections on insanity, including its relationships with automatism, self defence, and intoxication. To contact a Law Library to request detailed commentary from these sources click here: Auckland Law Library, Wellington Law Library, Christchurch Law Library, Otago Law Library
Onus of proof
– if insanity advanced by defendant then the onus is on the defendant to the balance of probabilities (assuming offence otherwise proved).
The prosecution may not normally present evidence of insanity. Nevertheless, if there is evidence of all aspects of the defence before the jury, the trial judge should direct on the defence after giving each party the opportunity to call evidence on the issue.
It is not necessary for the experts to agree which of (2)(a) or (2)(b) applies if they otherwise agree that the defence is made out. R v Allen HC Nelson CRI-2011-042-60, 14 September 2011
Automatism
If automatism is advanced so that there is an evidential basis shown then the Crown must rebut the defence beyond reasonable doubt.
Police v Bannin [1991] 2 NZLR 237 (HC), B v Police (1991) 7 CRNZ 55 is the starting point for any possible defence straddling the possibilities of insanity or automatism.
If natural imbecility or a disease of the mind results in automatism the verdict should be not guilty by reason of insanity, but automatism otherwise leads to an acquittal : R v Cottle [1958] NZLR 999 (CA); Bratty v Attorney-General for Northern Ireland [1963] AC 386, [1961] 3 All ER 523 (HL).
“Disease of the mind” and “automatism” are legal terms, not medical. Decisions about them are made by judges or juries having proper regard to expert evidence.
Personality disorders
Disease of the mind can, but will not necessarily, apply to a personality disorder – see Waitemata Health v Attorney-General (2001) 21 FRNZ 216, [2001] NZFLR 1122 (CA), at [71], per Elias CJ).
For a discussion of whether dissociative identity disorder is a disease of the mind see R v Hamblyn (1997) 15 CRNZ 66 (CA). Also Orchard, “Criminal Responsibility For the Other Self” [1997] NZLJ 431
Self defence
See Fairburn v R [2010] NZCA 44 citing R v Green [1993] 2 NZLR 513 (1993) 9 CRNZ 523 for the proposition that “even an insane delusion might require [self defence] to be put to the jury”. As noted in R v Bridger [2003] 1 NZLR 636, (2002) 19 CRNZ 676 (CA) the question of whether “the circumstances as [an accused] believes them to be” in s 48 of the Crimes Act applies to sane beliefs only is a very difficult question (at [34] – [35]).
In Oye v R [2014] 1 All ER 902 the defendant with insane delusions was permitted to utilise the first part of the self defence justification – whether he genuinely believed it was necessary to use force to defend himself – but his delusions were not permitted to inform the second part – what nature and degree of force was reasonable in the circumstances.
In Walsh v R (1991) 60 A Crim R 419 self defence based on a delusion was available, but only if insanity was first rejected. This would appear to be the logical result of the merging of the public policy explained in R v Cottle [1958] NZLR 999 (that the insane should not receive an unqualified acquittal) and the answer suggested in Green – if a delusion does not amount to, or is not accompanied by, insanity then the usual justifications become available.
Related legislation:
s 178 infanticide (also applies to attempted murder: R v O’Callaghan (1984) 1 CRNZ 185 (HC).
Criminal Procedure (Mentally Impaired Persons) Act 2003 – Part, 2, subpart 2 deals with acquittals on account of insanity.
Mental Health (Compulsory Assessment and Treatment) Act 1992
s 2 definition of “mental disorder” – mental disorder, in relation to any person, means an abnormal state of mind (whether of a continuous or an intermittent nature), characterised by delusions, or by disorders of mood or perception or volition or cognition, of such a degree that it—
(a) poses a serious danger to the health or safety of that person or of others; or
(b) seriously diminishes the capacity of that person to take care of himself or herself;—