Not all laws are equal

As most lawyers are aware, manslaughter by an unlawful and dangerous act is a common law offence that occurs, in broad terms, when a person unintentionally causes the death of another by an unlawful act which a reasonable person in the position of the accused would have realised would expose another person to an appreciable risk of serious injury. Courts have, however, expressed various views on what is an 'unlawful act' for this purpose. In particular, before a dedicated offence of culpable driving existed, there was debate on whether the multiplicity of driving offences in various road safety acts and regulations could constitute an unlawful act.

The high point in Australia for excluding driving offences from the unlawful act doctrine appears to be R v Rau [1972] Tas SR 59, where Burbury CJ states:

that for the purposes of motor manslaughter, the law places all such unlawful acts in the category of culpable negligence, and excludes them from the category of manslaughter constituted by killing by an unlawful act.

In R v Pullman (1991) 25 NSWLR 89, Hunt CJ at CL took up the issue, and, after extensively analysing the relevant cases, concluded:

The process of reasoning in these cases is conceded by all to be illogical, and it is obvious that some question of policy is involved as to where the line is to be drawn. In my opinion, however, a policy which necessarily excludes from the category of manslaughter based upon an unlawful and dangerous act any act which constitutes a breach of the Motor Traffic Regulations is quite unacceptable. In my view, a more appropriate dividing line — bearing in mind the way in which the cases have approached the problem to date — is to require the act upon which this category of manslaughter is based to be one which is unlawful otherwise than by reason of the fact that it infringes some statutory prohibition (by which term I include any regulatory
prohibition).

More recently, Lasry J in R v Nguyen [2010] VSC 442 considered whether offences under the Firearms Act 1996 could qualify for unlawful and dangerous act manslaughter. The three possible triggering offences were:

• A prohibited person must not possess, carry or use an unregistered firearm
• Any person must not possess, carry or use an unregistered firearm
• Any person must not carry or use a firearm while under the influence of intoxicating liquor or a drug

As Lasry J noted, unlike the driving offences considered in Pullman, these are all indictable offences that require proof of mens rea and attract substantial penalties. In contrast, the offences considered in Pullman were strict liability summary offences. The difference could scarcely be more stark.

Ultimately, Lasry J cites the dissentients in Wilson v R (1994) 174 CLR 313 who made this statement in the introductory part of their judgment:

There is now no difficulty about what constitutes an unlawful act for the purpose of this offence. An unlawful act is one which is contrary to the criminal law. Criminal negligence in the performance of an act which is otherwise lawful is not an "unlawful act". Where an act of that kind is involved, the case is one of manslaughter by criminal negligence, not manslaughter by an unlawful and dangerous act.

This statement, without any authority, raises more questions than it answers. When the law criminalises conduct on the basis of negligence, how can it be said that it is an act that is "otherwise lawful"? On what basis is a criminally negligent act "not an unlawful act"? Why is the case "one of manslaughter by criminal negligence, not manslaughter by an unlawful and dangerous act?" Regretably, neither the dissentients in Wilson or Lasry J answer these questions. Instead, Lasry J concludes:

In my opinion, it is correct to say that if the act said to constitute unlawfulness for these purposes was not one where the unlawfulness required proof of mens rea, then it would not be a crime that satisfies the test of unlawfulness for the purpose of unlawful and dangerous act manslaughter. On the other hand if it does and can be said to be causative of the death of the deceased then it is.

While a test of 'unlawful = mens rea offence' is most coherent and predictable than 'unlawful = unlawful for a reason other than just being a statutory offence', it does not address the need for a policy restraining the scope of possible unlawful acts, as identified lurking beneath the surface in Pullman. The test also arbitrarily excludes a range of strict liability offences that could well be highly dangerous. Environmental offences come to mind.

Interestingly, New Zealand has reached a similar position by concluding in R v Powell [2002] 1 NZLR 666 that crimes of negligence do not qualify as unlawful acts. That decision, however, was driven by the fact that many crimes of negligence in New Zealand require mere civil negligence, rather than the gross criminal negligence required in Australia by cases such as Nydam v R. Therefore, when the New Zealand parliament introduced section 150A of the Crimes Act 1961, which set the standard of negligence required before a breach of certain legal duties would be culpable, the court needed to prevent the prosecution from using negligence-based offences that are not specified in s150A as the relevant unlawful acts and thereby render s150A ineffective.

The result is that, in Australia, an unspecified range of offences are not sufficient to establish unlawful and dangerous act manslaughter, despite being a breach of the criminal law and objectively dangerous.
The test of dangerousness requires that a reasonable person would have realised that he or she was exposing another person to an appreciable risk of serious injury. If conduct meets that test of dangerous and is also a breach of the criminal law, why should the law care about the seriousness of the alleged unlawful act? Regretably, there does not appear to be any clear any to that question.

Postscript
While on the topic of manslaughter, it is also worth noting Williams J's decision in DPP v Singleton [2010] VSC 428, which rejected an interesting, though implausible argument that, when the majority in Wilson changed the dangerousness test to an appreciable risk of serious injury, rather than really serious injury, because of the risk of overlap with murder, this change only applied when the accused was also charged with murder on the indictment. If accepted, this argument meant that a more onerous test applied if the accused was charged with manslaughter alone, compared to the test if manslaughter is charged as an alternative to murder. Unfortunately, as Williams J makes clear, the caselaw has not always spoken with absolute clarity, and even the High Court has lapsed into describing the test as one of an appreciable risk of really serious injury.