Conspiracy between spouses - Namoa v The Queen [2021] HCA 13

Katharine Jeffreys


Ms Namoa was found guilty by a jury of an offence of conspiring to do acts in preparation for a terrorist act, contrary to sections 11.5(1) and 101.6(1) of the Criminal Code 1995 (Cth) . The offence took place between 8 December 2015 and 25 January 2016.

Ms Namoa and her sole co-conspirator,

Mr Bayda, married on 30 December 2015.

Before the trial, Ms Namoa applied for a permanent stay on the basis that she could not be guilty under the Criminal Code of a conspiracy that involved only herself and her husband. The trial judge refused the application. The NSW Court of Criminal Appeal (CCA) dismissed Ms Namoa’s appeal, concluding that a husband and wife can be guilty of conspiring with each other.

Ms Namoa appealed. In dismissing that appeal, the High Court (in a judgment by Gleeson J, with whom the remainder of the Full Court agreed) rejected Ms Namoa’s argument that the offence of conspiracy in s 11.5(1) of the Criminal Code does not apply to spouses who conspire only between themselves.

'Conspiracy' under the Criminal Code

Section 11.5(1) of the Criminal Code provides, relevantly, that 'a person who conspires with another person to commit an offence … is guilty of the offence of conspiracy to commit that offence …'.

In accordance with established principles for interpreting a statutory code, the Criminal Code is to be construed according to its natural meaning and without any presumption that its language was intended to do no more than restate the common law.

It was held in R v LK (2010) 241 CLR 177 that, subject to express statutory modification, the words 'conspires' and 'conspiracy' in s 11.5(1) bear their common law meaning. That is because those words had an established meaning within the criminal law when the Criminal Code was enacted, their use, without definition, in s 11.5(1) was therefore intended to be understood by reference to that legal meaning. (LK was not concerned with any question regarding the capacity of spouses to be guilty of a conspiracy.)

In Namoa , the High Court confirmed that the common law meaning of 'conspires', as referred to in LK, involves entering into an agreement to perform the actus reus of an offence with knowledge of facts that make the proposed acts unlawful.

Spouses are separate 'persons'

The High Court confirmed that there is no longer any principle in Australian common law that spouses form a single legal person. The appellant did not contend otherwise.

An independent rule?

The appellant contended that there is a common law rule, independent of the doctrine of unity between husband and wife, that spouses cannot be the sole parties to a conspiracy, and that this rule forms part of the established common law meaning of 'conspires' and 'conspiracy' for the purpose of understanding those words in s 11.5(1) of the Criminal Code .

To establish the existence of this common law rule, the appellant sought to rely on case law from New Zealand ( R v McKechie [1926] NSZLR 1), Canada ( Kowbel v The Queen [1954] SCR 498 ), the Privy Council ( Mawji v The Queen [1957] AC 126 ) and England and Wales ( Midland Bank Trust Co Ltd v Green [No 3] [1982] Ch 529 ).

The High Court found that these authorities did not assist the appellant, because of the different terms of the various statutes under consideration, and because of the courts’ reliance on the proposition that spouses were legally one person. None of these decisions concerned the meaning of 'conspiracy' or whether that meaning includes a rule excluding spouses.

Spouses can conspire under s 11.5(1)

The High Court therefore held that the use of the words 'conspiracy' and 'conspires' in s 11.5(1) of the Criminal Code does not incorporate into the offence any rule relating to spouses.

The High Court upheld the CCA’s interpretation that on the clear language of s 11.5(1), each party to a marriage is a 'person' and can therefore be guilty of conspiring with the other.

The court observed that this interpretation of the provision is supported by extrinsic materials relevant to the creation of the Criminal Code , in particular the interim report entitled 'Principles of Criminal Responsibility and Other Matters' (the Gibbs Committee Report) and the draft Model Code prepared by the committee later known as the Model Criminal Code Officers Committee (MCCOC), each published in 1990. The Gibbs Committee Report stated, 'The Review Committee can see no valid reason of social policy why the rule that there can be no conspiracy between husband and wife should be retained. That rule is based upon a fiction which is unacceptable in modern society.' The MCCOC’s report similarly stated, 'No protection is provided for spouses. Clearly a husband and wife can be guilty of conspiring with each other. Marital immunity is outdated; …'

Conspiracy between spouses at common law

It was unnecessary for the High Court to consider whether a rule of the type contended for by the appellant, namely that conspiracy does not apply to spouses, exists at common law, or has done at any time in the past.