Conspiracy to Commit Terrorism

What is a Criminal Conspiracy? The Legal Definition

In England and Wales, a criminal conspiracy is defined by Section 1 of the Criminal Law Act 1977. It is, at its core, an agreement between two or more people to commit a criminal offence. The conspiracy is complete the moment the agreement is made, regardless of whether the intended crime is ever carried out.

This means you can be charged with conspiracy to commit a terrorist act even if no violence occurs and no concrete steps are taken beyond the planning stage.

There are important exceptions to this rule. A person cannot be guilty of a conspiracy if the only other party to the agreement is:

• Their spouse or civil partner.
• A child under the age of 10.
• An undercover police officer or agent provocateur.

Terrorism conspiracy charges are often brought alongside specific offences under the Terrorism Act 2000 and the Terrorism Act 2006, creating a complex and layered prosecution case.

The Wide Range of Terrorism Offences

The law defines terrorism as the use or threat of action designed to influence a government, intimidate the public, or advance a political, religious, racial, or ideological cause, which involves serious violence or creates a grave risk to public safety. A conspiracy charge can relate to an agreement to commit any of the numerous offences within this framework, including:

• Acts of Violence: Planning acts causing serious physical harm, endangering life, or using explosives.
• Preparation for Terrorism (Section 5, Terrorism Act 2006): Engaging in any conduct in preparation for giving effect to an intention to commit acts of terrorism. This is an extremely broad offence.
• Fundraising and Financial Support (ss. 15–18, TA 2000): Raising, providing, or possessing money or property that you know or have reasonable cause to suspect will be used for the purposes of terrorism.
• Weapons Training (s. 54, TA 2000): Providing or receiving instruction in the making or use of firearms, explosives, or chemical, biological, or nuclear weapons.
• Membership and Support for Proscribed Organisations (ss. 11–12, TA 2000): Belonging to, or inviting support for, an organisation that the Home Secretary has banned. This also includes displaying articles (s.13) in a way that suggests membership or support.
• Possession of Articles and Information (ss. 57–58, TA 2000): Possessing an article or collecting/possessing information in circumstances which give rise to a reasonable suspicion that it is for a purpose connected with terrorism. The Counter-Terrorism and Border Security Act 2019 extended this to include viewing terrorist material online (s.58A).
• Encouragement and Dissemination (ss. 1–2, TA 2006): Publishing statements that are likely to be understood as directly or indirectly encouraging acts of terrorism, including the glorification of such acts.
• Travelling Overseas: Making plans to travel abroad for the purpose of engaging in terrorist activity.
• Online Extremist Content: Hosting, creating, or systematically sharing extremist content online.

Police Powers and Investigation Procedures

Terrorism investigations are conducted by specialist Counter Terrorism Policing units and often involve coordination with intelligence agencies like MI5, MI6, and GCHQ. They are granted exceptional powers, including:

• Arrest: A constable can arrest a person without a warrant whom they reasonably suspect to be a terrorist (s. 41, TA 2000).
• Pre-Charge Detention: Suspects can be held for up to 28 days without charge, subject to judicial approval, far exceeding the normal limits for other criminal offences.
• Stop and Search: Police have powers to stop and search individuals and vehicles without suspicion in areas designated by a senior officer (s. 47A, TA 2000).
• Port and Border Powers (Schedule 7): Examining officers at ports, airports, and border areas can stop, question, and detain individuals to determine if they are involved in terrorism. This can be done without suspicion.
• Warrants, Searches, and Seizure: Police can obtain warrants to search premises and seize vast amounts of material, including all digital devices.
• Use of Intelligence: Investigations rely heavily on intelligence, which may include covert surveillance, informants, and communications intercepts. This evidence is often highly sensitive and subject to special court procedures like Public Interest Immunity (PII) hearings or Closed Material Procedures, where the defendant and their legal team may not see all the evidence against them.

Real-World Examples of Terrorism Conspiracies

The Crown Prosecution Service has brought conspiracy charges in a wide variety of scenarios. Examples illustrating the breadth of the offence include:

1. A Logistics and Funding Cell: A group of individuals coordinating the purchase of camping equipment, vehicles, and mobile phones for an organisation operating overseas. They also raise funds through collections and transfer the money abroad through complex routes. Even with no direct involvement in violence, their agreement to provide material support constitutes a conspiracy.
2. An Online Propaganda Network: Several individuals across the country agree to systematically disseminate extremist propaganda videos and literature via social media and encrypted chat groups. Their aim is to recruit new members and encourage lone-wolf attacks. The agreement to disseminate these materials is a conspiracy to encourage terrorism.
3. A Local Attack Planning Group: A small group of radicalised students use online manuals to research the creation of improvised explosive devices. They scout a local school as a potential target and agree on a plan to carry out an attack. The conspiracy is formed at the point of their agreement, long before any device is built or any physical harm is caused.

Sentencing for Terrorism Offences

A conviction for a terrorism-related offence almost invariably results in a long custodial sentence. The maximum sentence depends on the specific offence. Below is a list of potential offences, alongside their expected maximum sentences.

Preparation of Terrorist Acts (s.5 TA 2006)

Life Imprisonment

Explosives Offences (with terrorist intent)

Life Imprisonment

Encouragement of Terrorism (s.1 TA 2006)

Up to 15 Years

Membership of a Proscribed Organisation (s.11 TA 2000)

Up to 14 Years

Inviting Support for a Proscribed Organisation (s.12 TA 2000)

Up to 14 Years

Terrorist Fundraising/Funding Arrangements (ss.15–18 TA 2000)

Up to 14 Years

Possession of an Article for Terrorist Purposes (s.57 TA 2000)

Up to 15 Years

Collection/Possession of Terrorist Information (s.58/58A TA 2000)

Up to 15 Years

How Courts Determine Sentences

When passing sentence, judges follow strict guidelines issued by the Sentencing Council. The court will assess:

• Culpability: The offender's role in the conspiracy (e.g., leader, significant participant, or lesser role), the level of planning and sophistication, and their motivation.
• Harm: The potential for harm that the conspiracy created, including the risk of mass casualties, psychological harm, or inciting public fear.
• Aggravating and Mitigating Factors: The sentence can be increased by factors like previous convictions or targeting vulnerable people. It may be reduced by factors such as youth, coercion, vulnerability, genuine remorse, or demonstrable efforts towards de-radicalisation.

The court may also impose extended sentences or "serious terrorism sentences" for offenders deemed to be a significant future risk.

The Critical Need for an Expert Defence Strategy

Defending against a terrorism conspiracy allegation requires a legal team with highly specialised knowledge. The prosecution's case often relies on vast amounts of digital evidence, complex intelligence, and expert testimony.

A robust defence strategy involves:

• Early Engagement: Intervening at the earliest stage to advise during police interviews, challenge pre-charge detention, and formulate a bail strategy.
• Scrutinising the Evidence: Meticulously analysing digital forensics, communications data, and surveillance evidence to identify weaknesses in the prosecution's case.
• Challenging Intelligence: Questioning the reliability and interpretation of secret intelligence and, where necessary, engaging robustly in closed material procedures.
• Addressing Legal Arguments: Arguing points of law on issues such as entrapment (where an undercover officer may have induced the offence), the definition of terrorism, or whether an organisation is legitimately proscribed.
• Instructing Experts: Engaging leading independent experts in forensics, digital analysis, psychology, or religious/political matters to counter the prosecution’s narrative.