[6-350] Introduction

Last reviewed: June 2023

The common law defence of necessity operates where circumstances (natural or human threats) bear upon the accused, inducing the accused to break the law to avoid even more dire consequences. There is, thus, some overlapping with the defence of duress. In R v Loughnan [1981] VR 443 at [448] it was held that the elements of the defence were that —


the criminal act must have been done in order to avoid certain consequences which would have inflicted irreparable evil upon the accused or upon others whom he or she was bound to protect;


the accused must honestly have believed on reasonable grounds that he or she was placed in a situation of imminent peril; and


the acts done to avoid the imminent peril must not be out of proportion to the peril to be avoided.

The imminence and seriousness of the threat, and the question of whether there were any possible alternative courses of action available, should be treated as important factual considerations relevant to the accused’s belief and the reasonableness and proportionality of the response, rather than technical legal conditions for the existence of necessity: R v Rogers (1996) 86 A Crim R 542 at 545–548. The availability of realistic alternative courses of action is a question of fact and not to be resolved by reference to whether the accused believed that to be the position: Veira v Cook [2021] NSWCA 302 at [46]. The defence relates to a response which “could not otherwise be avoided” and was the accused’s “only reasonable alternative”: Veira v Cook at [48].

In R v Cairns [1999] 2 Crim App Rep 137, it was held that an accused will have a defence of necessity if —


the commission of the crime was necessary, or reasonably believed to have been necessary, for the purpose of avoiding or preventing death or serious injury to himself or herself, or another;


that necessity was the sine qua non of the commission of the crime; and


the commission of the crime, viewed objectively, was reasonable and proportionate, having regard to the evil to be avoided or prevented.

The defence of necessity involves two questions that must be addressed: first, was the accused’s conduct in truth a response to a threat of death or serious injury; and second, if so, did the accused act honestly believing, on reasonable grounds, that it was necessary to do so to avoid the threatened death or serious injury: Veira v Cook at [24]. The defence does not extend to excuse criminal conduct undertaken otherwise than in response to an imminent threat of death or serious injury; it is insufficient if the accused merely believed the harm sought to be avoided was “not less than” any harm involved in the criminal conduct: Veira v Cook at [40]–[43].

The accused bears the evidentiary onus of establishing a basis for a defence of necessity and, thereafter, the Crown bears the onus of negativing the defence beyond reasonable doubt: R v Rogers at 547. The suggested direction for Duress [6-150] may conveniently be adapted to the case in which the defence of necessity is raised.