R v Siracusa (1990) 90 Cr App R 340

The defendants were involved in an international operation alleged to import prohibited drugs through the United Kingdom. The arrangements used commercial shipments, including furniture, to conceal substances obtained from different sources. Their convictions concerned conspiracies involving different classes of drugs. On appeal they challenged the directions on the agreements that had to be proved and on the degree of individual involvement necessary for conspiracy. The Court of Appeal considered whether an organiser could remain in the background yet adhere to an unlawful agreement, while maintaining the need to establish the particular criminal agreement charged.

Could knowing adherence to a criminal agreement be inferred from a defendant's role and conduct without overt participation in every stage of the operation?

The Court of Appeal dismissed the appeals against conviction. Agreement remains the essence of conspiracy, but it need not be expressed formally or demonstrated by overt participation in each operational act. A person's knowledge, conduct and circumstances may establish intentional adherence to the criminal purpose even when that person works in the background. The court's reasoning did not make mere presence or awareness sufficient. Its discussion of inactivity concerned an inference of agreement where knowledge and intention to further the enterprise were established. The jury also had to address the relevant charged agreements; proof of one different drug-importing agreement could not simply substitute for proof of the particular conspiracy alleged.

Participation in a conspiracy may be inferred from knowing, intentional adherence to the agreement, including a background role. Mere presence, association or knowledge is insufficient without the required agreement and intention. Siracusa does not permit conviction solely because a person failed to stop another's wrongdoing.

Siracusa is useful for separating evidence of agreement from the substantive acts carried out under it. Organisers may deliberately avoid visible operational tasks, so a lack of overt action does not settle the question. Equally, guilt cannot be inferred merely from association with offenders. Apply the statutory conspiracy requirements and examine the evidence supporting this defendant's intentional adherence. Where several offences or drug classes are alleged, maintain the connection between the agreement proved and the count charged.