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What is Conspiracy to Commit Murder?

Even if you were not the one pulling the trigger, you could receive a punishment as severe as the hitman. Strange, right? Well, that is the offence of conspiracy to commit murder. If you are alleged to be part of the group of individuals who planned the death of another person, you may find yourself being prosecuted for the serious criminal offence of conspiracy to commit murder. Conspiracy law is drafted widely to enable the courts to punish organised criminals and gang members who operate together in order to take the life of others. Therefore, in some cases, even if you were not part of the murder incident itself but were involved in planning it, you could face a hefty custodial sentence. If you have been charged with conspiracy to commit murder, you may be wondering what the prosecution will need to prove in order to convict you and trying to figure out the defences that you could rely upon. This article aims to answer all your questions, and more.

What is the offence of conspiracy to commit murder?

Conspiracy to commit murder is an offence under Section 1(1) of the Criminal Law Act 1977, which relates to conspiracy generally and provides that the sentence for a charge of conspiracy is tied to the sentence of the relevant offence. This means that because murder is punishable by way of a life sentence, if you are convicted of conspiracy to commit murder, you could face a life sentence for that, too.

In order to be found guilty of conspiracy to commit murder, the prosecution must find that you:

  • agreed with any other person or persons that a course of conduct shall be pursued
  • which, if the agreement is carried out in accordance with the plan either
    • will amount to one or more of the parties committing murder
    • or would amount to one or more of the parties committing murder were it not for facts which render the commission of the offence impossible.

There are other, more complicated, parts of that law that essentially say that you cannot be convicted of conspiracy if you are not aware of key information that would make committing the offence possible at the time of concocting the conspiracy. For example, say that you were discussing the idea of murdering the President of the United States of America if he ever visits Buckingham Palace. In order for the discussion to become a conspiracy, it would need to relate to an actual plan of the President to visit Buckingham Palace on a particular date; it couldn’t just be a vague statement that ‘sort of’ sounds like a plan.

It is possible to be prosecuted for conspiracy to commit murder in a jurisdiction outside of England and Wales pursuant to Section 1A of the Criminal Law Act. This law enables the Crown Prosecution Service (CPS) to prosecute an offence that is planned at least in part in the UK, but would be committed elsewhere, provided that the act is also prohibited in the country where it would be committed. Murder is a criminal offence in all countries of the world. Therefore, conspiracy to commit a murder abroad could be prosecuted under this legislation.

Conspiracy to commit murder is different from attempted murder. Attempted murder relates to an unsuccessful effort to murder someone. By contrast, conspiracy to murder relates to a plan to murder someone. You can be prosecuted for making the plan, even if no murder attempt actually ever takes place.

Examples of conspiracy to commit murder

Here are some examples of conspiracy to commit murder:

  • You and your brother agree to kill your sister because you do not agree with her choice of husband. Your sister discovers your plan and informs the police.
  • Two police officers in an undercover drug operation realise that their cover has been blown and their life is at risk. They agree to kill the person who has discovered them in order to protect themselves, regardless of whether anyone is actually coming after them.
  • Three members of a far-right political group hatch a plot to assassinate the Mayor of London. The idea is that one of them will shoot him as he attends a public event. The mayor withdraws from the event at the last moment because he is unwell. The plot is discovered by another member of the political party, who reports them to the police.
  • You and your cousin agree to murder your father so that you claim insurance money for his death. Your cousin makes the plan with you but then at the last moment, he changes his mind and telephones you to inform you that he does not want to go ahead with it. Another family member overhears the conversation and reports it to the police. Even though your cousin later retracted from the plan, both you and your cousin could be prosecuted for conspiracy to murder.

What are the defences to conspiracy to commit murder?


Not all agreements to commit a crime can be charged under the offence of conspiracy. Agreements cannot be a conspiracy where they are between a person and one of other person who is:

  • their spouse or civil partner
  • their intended victim, or
  • a child under the age of criminal responsibility (10 years old)

However, the person could still be charged with conspiracy if the agreement is between them, say, a spouse, and another person.

For example, a man could not be charged with conspiracy for making a plan to kill his neighbour with his wife, and eight-year-old son. That said, the same man could be charged with conspiracy if he also made the plan with his adult son. These exemptions might seem illogical. Why should a person be relieved of committing a criminal offence because their co-conspirator was a child, or their spouse? Some years ago, the Law Commission published a paper recommending that these exemptions be abolished. However, to date, they remain in law.

Defences could include:

  • Negotiations: a common defence to conspiracy is to argue that you had not made a plan to commit the offence. A ‘substantial reservation’ to the plan, i.e. a key piece of information that is missing, could mean that the plan is still at the stage of negotiations.
  • Intoxication by drugs or alcohol: if you were involuntary intoxicated at the time of events, it may be found that you did not have the necessary mental intention to conspire to commit a murder.
  • Self-defence: the law says that if you are attacked, you may use force that is reasonably necessary to defend yourself. You may also use reasonable force to defend another person, property, to prevent crime, or to conduct a lawful arrest. In practice, this defence would be tough to apply to conspiracy to commit murder because self-defence usually only applies to your reaction in the spur of the moment, not a pre-meditated plan.
  • Automatism: if you were not aware of your actions when planning the murder, in some rare circumstances, you may be able to rely upon the defence of automatism. If you were under the voluntary influence of alcohol or illicit drugs, you will not be able to rely on this defence.
  • Insanity: if you were suffering from a mental illness at the time of forming the conspiracy and the court finds that because of it you lacked the ability to reason such that you did not know that the act that you were planning was against the law, you may be acquitted on the grounds of insanity.
  • Mistake: there is a general defence of mistake where you were mistaken as to certain circumstances and would not have committed the offence if you had known otherwise. This may also be difficult to prove in conspiracy cases, but it could happen.

Other scenarios:

  • Prevention of crime: it is not a defence to enter into a conspiracy for the purpose of preventing crime. For example, a police officer who enters a conspiracy in order to expose a drug deal could be guilty of conspiracy if the drugs are delivered before the other participants in the deal are arrested.
  • Suicide pact: a suicide pact would not be a conspiracy to murder because the agreement is with the victim only. Note that if you entered into a suicide pact where you killed the other person and the court is satisfied that you had the settled intention to die yourself, this could be a defence to murder.

Where to get further help?

If you have been charged with conspiracy to murder, you are probably aware that this is a very serious offence. Make sure that you have the best possible legal team on your side. At Stuart Miller Solicitors, our defence team has successfully secured the acquittal of thousands of defendants at the Crown Court. We will give you nuanced and realistic advice on your case. Contact us for a no obligation consultation today.

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