When it comes to criminal law, you may have noticed that both state and federal governments have enacted a range of criminal offences.
In NSW, the major piece of legislation that sets out criminal offences is the Crimes Act 1900, but there are dozens of other pieces of legislation that create many more offences. One of the most notable of these is the Drug Misuse and Trafficking Act 1985 which prescribes many drug offences including drug possession and drug supply.
Some of the matters dealt with by Commonwealth (or federal) laws include immigration offences, tax fraud, money laundering, human trafficking, drug importation and social security fraud.
But what happens if state and federal laws both attempt to legislate on the same issue, or impose differing penalties?
This is where the Constitution steps in.
What powers do the states and the Commonwealth when it comes to creating offences?
Although it may not always seem to be the case, the Commonwealth can’t simply legislate about anything they want to: their powers are set out in section 51 of the Constitution.
There are 39 ‘heads of power’, which cover anything from trade and commerce to marriage, postal services and taxation.
For example, section 51 (v) of the Constitution allows the government to make laws about “postal, telegraphic, telephonic, and other like services”.
Under this head of power, the Commonwealth has created offences related to telephone and postal communication, including misusing emergency numbers, making telephone threats, sending threatening letters and stealing Australia post mail.
Anything that is not covered under section 51 of the Constitution is the domain of the states – although states can agree to refer powers under section 51 (xxxvii).
There are times when both the Commonwealth and states may have jurisdiction to enact legislation governing a particular area of law – so what happens if the laws conflict?
Section 109 of the constitution and the criminal law
Section 109 of the Constitution says that when a federal law is inconsistent with (or conflicts with) a state law, the Commonwealth law will prevail, and the state law will be invalid.
However, the conflicting state law will only be invalid to the extent of the inconsistency.
This means, for example, that if one provision of a state law is inconsistent, the rest of the act will still be valid.
And if the conflicting Commonwealth law is repealed, the state law will once again commence operation.
State and Commonwealth provisions for a particular area of the law can sometimes exist together, complementing one-another.
But in other cases, Commonwealth provisions might make it clear that federal law is intended to ‘cover the field’, which excludes state legislation from having any operation.
In order to have a state law declared invalid, it must be found to be inconsistent by the High Court of Australia.
Has this ever happened?
A number of cases have dealt with the issue of inconsistent state and federal laws.
In Momcilovic v the Queen (2011), the High Court was asked to decide whether a Victorian law conflicted with a Commonwealth one.
Vera Momcilovic was convicted under Victorian legislation (section 71AC of the Drugs, Poisons and Controlled Substances Act 1981 (Vic)), which prescribed the offence of trafficking methylamphetamine.
However, trafficking methylamphetamine is also an offence under section 302.4 of the Commonwealth Criminal Code.
At the time the case was decided, the Victorian legislation prescribed a higher maximum penalty than the Commonwealth Act.
Momcilovic attempted to have her conviction overturned on the basis that the state law was inconsistent with the Commonwealth offence.
However, the High Court rejected her claim, finding that the Victorian offence was not inconsistent because both could be obeyed simultaneously, and the Commonwealth provision specifically expressed that it was not intended to exclude or limit state jurisdiction.
In other cases, such as that of Dickson v R, the High Court did rule that a state offence of conspiracy was inconsistent with a similar Commonwealth offence.
Most interestingly, it is possible for the Commonwealth to deliberately use its powers to overturn a state law if it falls within one of the Commonwealth heads of power. Although this is highly unusual, it happened back in 1994.
In that year, the Tasmanian Parliament refused to repeal a provision which made it a criminal offence to have homosexual sex.
Acting on the advice of the Attorney-General, the Commonwealth government passed legislation which overruled the Tasmanian offence.
Section 4 of the Human Rights (Sexual Conduct) Act 1994 states that: “sexual conduct involving only consenting adults acting in private is not to be subject, by or under any law of the Commonwealth, a State or Territory, to any arbitrary inference with privacy.”
The Tasmanian law was challenged in the case of Croome v Tasmania (1997), where it was declared invalid.
Although there are cases which have invoked section 109 of the Constitution, they are few and far between.
And while criminal law is primarily a domain for the states, the Commonwealth is playing an ever-increasing role.