Chapter 3
The current law

Partial defences and sentencing

3.15Partial defences are only available in homicide cases. They recognise situations where lethal force is used in circumstances that mitigate the defendant’s culpability or blameworthiness for using violence. Unlike self-defence, which is a complete defence, partial defences operate only to reduce murder to manslaughter.145 Their historic rationale was to circumvent the mandatory sentence for murder (whether capital punishment or, more recently, life imprisonment) in cases with mitigating features.146
3.16The mandatory life sentence for murder was abolished in New Zealand with the passage of the Sentencing Act 2002, and the partial defence of provocation was abolished in 2009.147 The history behind the repeal of provocation is discussed in Chapter 4 of this Issues Paper.
3.17The only remaining partial defences under New Zealand law are infanticide and killing pursuant to a suicide pact, both of which are not relevant to victims of family violence who kill their abusers.148 Unlike a number of other jurisdictions, New Zealand law does not recognise excessive self-defence as a partial defence. Where the defendant uses more force than the law allows, he or she is liable for the full consequences of the offence – there is no “intermediate category of exculpation”.149 Nor does New Zealand law recognise a general partial defence of “diminished responsibility”, although infanticide is a limited form of that defence.150 These partial defences are discussed in Chapters 6 and 8 of this Issues Paper.

Assessing defendant culpability at sentencing

3.18Under the Sentencing Act, life imprisonment is the presumptive sentence for murder, but a court may impose a lesser sentence if “given the circumstances of the offence and the offender, a sentence of imprisonment for life would be manifestly unjust”.151 In R v Rapira, the Court of Appeal held manifest injustice in terms of section 102 would be established only in exceptional cases but noted Parliament’s apparent intention that cases with evidence of prolonged and severe abuse might qualify.152
3.19The Sentencing Act lists a number of mitigating factors the court must take into account in sentencing and provides that the court can take into account any other mitigating factor it thinks fit.153 Relevant mitigating factors that must be taken into account include:154
(a) the conduct of the victim (in homicide cases, the deceased);
(b) that the defendant has, or had at the time the offence was committed, diminished intellectual capacity or understanding;
(c) any remorse shown by the defendant; and
(d) any evidence of the defendant’s previous good character.

3.20Sentencing decisions in respect of victims of family violence who killed their abuser are discussed in Chapter 5.

145Infanticide can also operate to reduce manslaughter to the offence of infanticide, which carries a maximum penalty of three years’ imprisonment. Crimes Act 1961, s 178.
146Law Commission, above n 8, at 9.
147The Law Commission had recommended abolition, in Some Criminal Defences with Particular Reference to Battered Defendants (NZLC R73, 2001) and again in The Partial Defence of Provocation (NZLC R98, 2007). These reports are discussed in Chapter 4.
148Infanticide, as we note below in Chapter 8, is a dual-role or “hybrid” criminal provision. That is, it can be charged as an offence or pleaded as a defence if a defendant is charged with murder or manslaughter, in which case the prosecution must negative the defence. In either case, it attracts a maximum sentence of three years’ imprisonment (Crimes Act 1961, s 178(1)).
149Simester and Brookbanks, above n 129, at 500.
150At 560 and 590.
151Sentencing Act 2002, s 102.
152R v Rapira (2003) 3 NZLR 794, (2003) 20 CRNZ 396 (CA) at [121]; R v Wihongi, above n 84, at [83]–[85].
153Sentencing Act 2002, s 9(4).
154Sentencing Act 2002, s 9(2)(a)–(g).