If you’ve been charged with a conspiracy offence or are the subject of an alleged conspiracy, you’re facing a serious criminal law matter involving allegations that you agreed with one or more people to commit an offence. Conspiracy charges are among the most complex in criminal law, allowing prosecutors to secure convictions based on criminal conduct, agreements and plans, rather than completed criminal acts.
This fact sheet explains conspiracy charges under Australian law, the elements prosecutors must prove, how joint criminal enterprise works, extended joint criminal enterprise, withdrawal as a defence, penalties, and how conspiracy relates to the principal offence.
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What is Conspiracy?
The offence of conspiracy is an agreement between two or more people to commit a criminal offence. Conspiracy requires proof of both the agreement and mens rea, meaning the intention that the offence would be carried out. Importantly, the offence exists once the agreement is made, regardless of whether the planned offence is completed.
It is prosecuted under section 11.5 of the Criminal Code Act 1995 (Cth), referred to here as the Criminal Code, for Commonwealth offences, and under equivalent common law or statutory provisions in state jurisdictions, including the Crimes Act in New South Wales. In Queensland, provided the relevant elements are met, equivalent provisions apply.
| Element | What Prosecution Must Prove | Evidence Types |
| Agreement | Two or more people agreed to commit an offence | Phone intercepts, messages, witness testimony |
| Intent | You intended the offence would be committed | Planning discussions, preparatory acts |
| Overt Act (some jurisdictions) | At least one person took a step toward completing the crime | Purchasing materials, surveillance, travel |
When You Can Be Convicted for Someone Else’s Crime
Joint Criminal Enterprise
Joint criminal enterprise (JCE) means if you take part in a crime with others, you can be held criminally responsible for everything the group does, even acts you didn’t personally commit. This applies to alleged conspirators regardless of their specific role in the planned offence.
Basic Joint Enterprise
If you agree to commit a crime with others, you’re responsible not just for your own actions, but for acts committed pursuant to the agreed crime by your co-offenders.
For example:
- You agree to commit a burglary or even an attempted burglary
- During the burglary, your co-offender assaults the homeowner, causing bodily harm
- You can be convicted of assault even though you didn’t personally assault anyone, because the assault was an act contemplated in furtherance of the agreed burglary
Extended Joint Criminal Enterprise
Extended JCE makes you liable for crimes committed by co-offenders that were not specifically agreed upon, if:
- The crime was a possible incident of carrying out the agreed crime, and
- You foresaw the possibility the crime might be committed
This is particularly harsh. For example:
- You participate in a drug supply meeting
- Your associate unexpectedly shoots a rival dealer
- If you foresaw the possibility violence or bodily harm might occur (even if you didn’t want it or agree to it), you can be convicted of murder
Withdrawal As A Defence
You can escape conspiracy liability by voluntarily desisting, withdrawing from the agreement on your own accord before the crime is committed. Withdrawal requires:
- Clear communication to other parties that you’re withdrawing
- Taking reasonable steps to prevent the crime (where possible)
- Withdrawal occurring before any substantial acts in furtherance of the conspiracy
Simply changing your mind privately is not sufficient; you must actively disassociate from the conspiracy.
Where a person breaks from the conspiracy but fails to take reasonable steps to notify other parties or prevent the planned offence, courts may find the withdrawal ineffective. Where you are the only other party to the agreement, withdrawal terminates the conspiracy but you may still face liability for acts already committed pursuant to the agreement.
Penalties for Conspiracy
Under Commonwealth law (s11.5), conspiracy to commit an offence carries the same maximum penalty as the substantive offence.
For example:
- Conspiracy to murder: life imprisonment
- Conspiracy to import commercial quantity of drugs: life imprisonment
- Conspiracy to commit fraud: 10 years imprisonment
State jurisdictions have similar penalty structures.
Frequently Asked Questions
Can I Be Charged Even if the Crime Didn’t Happen?
Yes. Conspiracy is a complete offence once the agreement is formed and there is intent to carry it out. The planned offence does not need to be completed. not even an attempted offence needs to reach its conclusion for a conspiracy charge to apply. This is why conspiracy is such a powerful prosecutorial tool, police can intervene and charge alleged conspirators before any harm occurs.
How do I withdraw from a conspiracy?
You must clearly communicate your withdrawal to co-conspirators, take reasonable steps to prevent the crime where possible, and withdraw on your own accord before any substantial acts in furtherance of the conspiracy occur. A private change of mind is not sufficient.
What’s the difference between conspiracy and being an accessory?
An accessory helps someone commit a crime after the fact, for example, helping them hide or flee. Conspiracy is different: it’s about conspiring, agreeing beforehand, to commit a crime together. Conspiracy charges are generally more serious because they target the planning itself, not just what happened afterwards.
Can I be charged with conspiracy even if I didn’t know all the details of the plan?
Yes. You don’t need to know every detail of what was planned. As long as prosecutors can prove you knew the general nature of the alleged conspiracy and intended for the crime to be carried out, that’s enough. Being kept in the dark about specifics is not a complete defence.
What penalties you face when conspiring to commit offences depend on the circumstances of your case, the jurisdiction, the nature of the criminal conduct, and your level of involvement. This is a complex legal matter in which you require legal advice as early as possible.
What if I was pressured or threatened into joining the conspiracy?
Duress can be a defence to conspiracy charges. If you can show you only agreed to participate because you were threatened with serious harm and had no reasonable way to escape the situation, this may be available to you. However, duress is a difficult defence to run and requires strong evidence. Whether this or any other legal matter involving criminal conduct applies to your situation is exactly the kind of question experienced lawyers need to assess early.
Contact Our Conspiracy Lawyers
Conspiracy and joint criminal enterprise charges are legally complex and require expert representation to challenge the prosecution’s evidence of agreement and intent. To be found guilty of a conspiracy offence, the prosecution must prove each element beyond reasonable doubt.
At O’Brien Criminal and Civil Solicitors, our experienced lawyers understand how to defend conspiracy charges, establish withdrawal defences, and contest extended JCE liability. We build a strong defence strategy tailored to your criminal law matter and the specific circumstances of your case.
Call O’Brien Criminal and Civil Solicitors on 02 9261 4281 or fill in the form below.
