This module is a resource for lecturers  


Criminal justice responses


To the extent that counter-terrorism activities are grounded in an efficient and transparent criminal justice process that respects the principles of the rule of law and human rights, they can offer a peaceful, accountable and legitimate response to terrorism. This kind of criminal justice response to terrorism can help avoid or mitigate the risk of unreasonable and/or unlawful use of force outside the protections and procedural guarantees offered by the due process of law. It can reinforce a society's commitment to the rule of law and human rights, even when living under terrorist threats.

The role of the criminal justice system in countering terrorism is a challenging one. Indeed, the primary objective of counter-terrorism strategies must be to prevent terrorist incidents from taking place, and in some cases law enforcement agencies are able to prevent terrorist attacks from occurring.  However, some existing criminal justice practices are less effective when it comes to preventing terrorist conspiracies from achieving their aim or a terrorist threat is too extensive for available resources to cope with. A forward-looking, preventive and well-funded criminal justice strategy against terrorist violence requires a comprehensive system of substantive offences, investigative powers and techniques, evidentiary rules and international cooperation. The goal is to proactively integrate substantive and procedural mechanisms to reduce the incidence and severity of terrorist violence, and to do so within the strict constraints and protections of the criminal justice system and the rule of law. There can be significant accompanying challenges, however, especially for less well-resourced States, to implement all the recommended measures for law enforcement and criminal justice systems together with the requisite levels of technical capacity.

Criminal justice systems have approached these challenges differently, depending on their legal tradition, their level of development, their relative institutional sophistication and their own cultural circumstances. In some instances, a perceived urgent need to respond to a specific threat has led States to improvise new criminal justice approaches, which risk contravening recognized international human rights instruments and normative standards. Furthermore, there is scope for strengthening the capacity and effectiveness of national legal and criminal justice systems in many States to cooperate at the international level with a variety of rule of law-based counter-terrorism initiatives. This has resulted in additional stress being placed on the already limited capacity of many criminal justice systems and has perhaps weakened or compromised their ability to function within basic rule of law and human rights principles.


Concepts of international criminal justice and international criminal law

Sometimes, in the context of prosecuting international crimes, the term "international criminal justice" is used. In terms of what this concept means, as the late Antonio Cassese observed: "The term international criminal justice is vague. What is contemporarily meant by it is the application of the principle of accountability for certain international crimes, whether before an international or national judicial body. Such a body must be duly constituted and impartial, and its legal processes must be fair and in accordance with international standards." (Cassese, 2009, p. 131).

For the current purposes, the term is used to refer to international crimes that terrorists may be prosecuted for, whether they are treaty-based crimes of terrorism - i.e. their legal source is an international treaty such as one of the universal conventions against terrorism or one of the core customary international crimes e.g. crimes against humanity. Although the latter do not expressly deal with terrorism related crimes, as will be explained below, in certain circumstances they can extend to terrorism-related crimes. Both of these international crimes form the basis of international criminal law, which is a body of public international law. Notably, in contrast to the other international legal regimes underpinning the United Nations CT Strategy discussed in Module 3, a fully coherent international criminal law regime, with accompanying mechanisms, governing terrorism and counter-terrorism does not yet exist.

In terms of its sources, whilst international criminal law is founded on article 38(1) of the Statute of the International Court of Justice (explained in Module 3), the exact legal source, scope and parameters of any international crime will often be determined by the legal instrument of the statute of the organ in which the crime is prosecuted. This can lead to some divergences in approach, including if and how terrorism-related crimes may be directly or indirectly prosecuted as international crimes. In turn, generally, an international crime attacks the fundamental values of the international community, such as peace and security, including due to the systematic or large scale violence involved.

In terms of where these international crimes are prosecuted, with the exception of the Special Tribunal for Lebanon, there are no international criminal courts or tribunals with dedicated jurisdiction over terrorist crimes. Some of the most heinous and high profile cases may be heard by an international criminal court or tribunal, such as the International Criminal Court, the jurisdiction of which is sourced in the Rome Statute of the International Criminal Court 1998 (Rome Statute). Alternatively, an ad hoc criminal tribunal may be created, such as those for former Yugoslavia and Rwanda, which are sourced in special Statutes provided by Chapter VII Security Council resolutions. On occasion, a hybrid court may be created, such as the Special Court for Sierra Leone or the Extraordinary Chambers in the Courts of Cambodia, which are sourced in both international and domestic law.

Usually, however, terrorist crimes (as defined in the universal instruments against terrorism) fall into the category of national criminal law of international concern. As such, they will be prosecuted by a national court where these crimes have been incorporated into national law, whether under a monist or dualist system (see Module 3). For example, domestic legislation criminalizing genocide, war crimes and torture is often enacted to implement a State's obligations under the Genocide Act 1948, the Geneva Conventions 1949 or the Convention against Torture 1984. In addition, their respectively articulated crimes can exist under customary international law on which some national courts will rely directly without the need for further legislation.

As such, the criminal justice response to terrorism is therefore essentially framed by national law, which itself must comply with various aspects of international law. There are thus several components of international law that are directly relevant to the national criminal justice response to terrorism. In addition to treaty-based obligations stemming from their ratification of the universal legal instruments against terrorism and several legally binding obligations imposed through the relevant Security Council resolutions on counter-terrorism, States also have a number of legal obligations under other branches of international law, including international human rights, humanitarian, refugee and customary international law examined in Module 3. This includes the core international crimes considered below.


Elements of crime

Effective criminalization of various acts associated with terrorist activities is a prerequisite to intervention by the criminal justice system. Criminalization is not only a legal obligation for States parties to the various instruments against terrorism but is also a prerequisite for effective international cooperation. States parties are expected to establish under their domestic law a number of offences called for by the conventions and protocols relating to terrorism and other related forms of crime. They must also ensure that those offences are punishable by appropriate penalties that take into account the gravity of the offences.

In order to do this, States must define the elements of terrorist offences in accordance with their general criminal law. While doing so, they must also ensure that the new criminal law provisions comply with their other obligations under international law, in particular international human rights, refugee law and humanitarian law.

There are two key elements to any crime, including international crimes: a material element ( actus reus) and a mental element ( mens rea).

Material element

The objective actus reus element of international crimes is typically concerned with their conduct, consequences and circumstances. The conduct element can consist of an act or omission, as is provided for within the text of the instrument forming the legal basis for its prosecution, e.g. murder, mass killing, serious bodily harm,kidnapping, bombing or hijacking in the instance of terrorism-related offences.

The consequences of the commission of an international crime extend to all the effects of the criminal conduct, such as the harm caused (e.g., injury to persons or damage to property). In the case of international terrorism, the conduct must have a transnational element to it, i.e., the conduct is not limited to the territory of one State with no foreign element or link (see further discussion on jurisdiction below). Each international instrument against terrorism articulates this requirement in a different manner. For example, article 13 of the International Convention against the Taking of Hostages 1979 states that: "This Convention shall not apply where the offence is committed within a single State, the hostage and the alleged offender are nationals of that State and the alleged offender is found in the territory of that State." Similarly, see article 4 of the Convention for the Suppression of Unlawful Acts against the Safety of Maritime Navigation 1988. The requirement that a transnational element is present is consident with the objective of the instruments, to oblige States to investigate and prosecute crimes related to international acts of terrorism, and to facilitate related international cooperation. However, in practice, many States have established as criminal offences the acts required by the instruments, without express requirement for the transanational element provided in the instruments.

Similiarly, as is explained in more detail below, in relation to the universal instruments against terrorism, in the absence of international agreement on a definition of terrorism, the approach adopted by States traditionally was to criminalize specific objective material elements of conduct within each of the treaties, which could then be prosecuted within national courts, normally without using the term "terrorist". In a nutshell, Cassese summarizes these as follows (Cassese, 2006, p.939):

  • (i) [A]cts that, whether or not they are offences under national law, may or do jeopardize the safety of aircraft, or of persons or property therein or which jeopardize good order and discipline aboard (article 1(b) Tokyo Convention 1963).
  • (ii) Unlawfully taking control, by force or threat thereof or by any other form of intimidation, of an aircraft in flight (article 1(a) Hague Convention 1970).
  • (iii) Acts of violence against persons on board an aircraft in flight or against the aircraft (article 1(1) Montreal Convention 1971).
  • (iv) Murder and other violent acts against internationally protected persons or their official premises, private accommodation or means of transport (article 2(1) Internationally Protected Persons Convention 1973).
  • (v) Unlawful possession, use, transfer or theft of nuclear material as well as threat to use it (article 7 Vienna Convention 1979).
  • (vi) Taking control of a ship by force or threat thereof or any other form of intimidation or acts of violence against persons aboard or against the ship (article 3(1) Rome Convention 1988).
  • (vii) Taking control over a fixed platform by force or threat thereof or any other form of intimidation,or acts of violence against persons on board or against the platform (article 2 Rome Protocol 1988).
  • (viii) Acts of violence against persons at an airport serving international civil aviation or against the facilities of the airport (article II Montreal Protocol 1988).
  • (ix) The manufacture, or the movement into or out of a territory, of unmarked plastic explosives (article II and III Montreal Convention 1991).
  • (x) The delivery, placing, discharging or detonation of explosive or other lethal device in a place of public use, a state or government facility, a public transportation system or an infrastructure facility (article 2(1) Suppression of Terrorist Bombings Convention 1998).

Mental element

The subjective mens rea element refers to the state of mind of the accused person at the time of the commission of the alleged international crime, i.e., his or her intent or purpose. Whereas all crimes require the presence of general intent, i.e., that the prohibited conduct occurs, as with the crime of genocide, or, less often that the accused was so grossly reckless as not to care whether certain consequences would be likely to occur, international terrorist crimes require that a specified intent is proved. Normally, in the case of terrorism, the instrument will specify that this specific intent is to spread terror among the population or to compel a government or international organization to perform or abstain from a particular act. As Antonio Cassese observed, a further unique element for terrorism relates to the underlying motive for the commission of the crime:

The criminal conduct must not be taken for a personal end (for instance, gain, revenge or personal hatred). It must be based on political,ideological or religious motivations. Motive is important because it serves to differentiate terrorism as a manifestation of collective criminality from criminal offences (murder, kidnapping and soon) that are instead indicative of individual criminality. Terrorist acts are normally performed by groups or organizations, or by  individuals acting on their behalf or somehow linked to them ... It is this factor that transforms the murderous action of an individual into a terrorist act. (Cassese, 2006, p. 937).

Examples are the 1979 International Convention Against the Taking of Hostages (article 1(1)) and 1999 Suppression of Terrorist Financing Convention (article 2(1)(b)), both of which characterize the terrorist actions they deal with as intended to compel a State or an international organization to do or to abstain from doing any act; in addition, the latter Convention contemplates the purpose of intimidating a population.

Prior to the national counter-terrorism legislative action triggered by Security Council Resolution 1373 (2001), although terrorism was considered to represent a significant threat to national security, within many domestic legal systems it was still framed as an ordinary crime, with no special mens rea requirement (such as a political element). Consequently, it was commonly prosecuted in terms of the associated criminal acts (especially murder, assault, damage to property, and arson), or within the parameters of conventional national security or public order offences (e.g. treason, rebellion, sedition, and treachery, or by resort to offences under emergency laws in exceptional cases).


Common law and civil/continental systems

One further issue, which should be mentioned, is that important differences can exist in the implementation, formulation and enforcement of terrorist crimes between common law and civil/continental law systems, even within them. This can add a further layer of tension, which can also be translated across to the prosecution of such crimes in international fora. (See further Fletcher, 2009, pp. 104-110).

For example, the offences of conspiracy and criminal association are obvious models for preventive intervention against the planning and preparation of criminal acts. Criminalizing conspiracies to commit a terrorist act (even when the terrorist act has not yet been carried out), however, depending on the national law and the legal tradition, may raise all kinds of evidentiary difficulties. Indeed, negotiations for the 1998 Rome Statute rejected the crime of conspiracy even in the context of such a grave crime as genocide although conspiracy is provided for within the text of the 1948 Convention on the Prevention and Punishment of the Crime of Genocide and included as a basis of criminal liability in the founding Statutes of the ad hoc tribunals for former Yugoslavia and Rwanda. This is reflective of the view of a number of States, which reject the notion of a crime of conspiracy.

That said, there are ways around such difficulties. Criminal responsibility at a time preceding actual violence can be established in law through the civil/continental law concept of association de malfaiteurs and/or the common law concept of "conspiracy", both of which prohibit agreements to commit crime. For these offences to be complete, the intended harmful act need not be attempted or accomplished, although some laws require the commission of a preparatory step to carry out the group's purposes. It is also possible to criminalize financial preparations of terrorist acts, as now required of States parties to the 1999 International Convention for the Suppression of the Financing of Terrorism. This relatively new approach introduces a deliberate strategy to permit intervention before a terrorist atrocity has been committed or attempted, which is in everyone's interest. Instead of defining a violent offence that can be punished only if it succeeds or is attempted, article 2 of the 1999 Convention requires the criminalization of the (non-violent) financial preparations that precede nearly every terrorist attack.



In order to prosecute an international crime, it is also necessary to establish jurisdiction. This is the power of each State under international law to prescribe and enforce its domestic laws or the power of an international tribunal to enforce its statute. In terms of States, however, as O'Keefe has articulated: "A state's 'jurisdiction'....refers to its authority under international law to regulate the conduct of persons, natural and legal, and to regulate property in accordance with its municipal law. Jurisdiction can be civil or criminal." (O'Keefe, 2004, p. 736).

A State's jurisdiction is exercised in three forms, corresponding to the three branches of government:

  • Legislative (or prescriptive) jurisdiction  refers to the competence to prescribe the scope of domestic law.
  • Judicial jurisdiction  refers to the ability of courts to apply domestic laws (e.g. in the case of the international instruments against terrorism).
  • Enforcement jurisdiction  refers to the ability of States to enforce their laws. Unlike the two others, this form of jurisdiction may not always benefit from extraterritorial reach. (UNODC, 2010, p. 46).

The "establishment" should be clearly distinguished from the actual "exercise" of jurisdiction. Under the universal counter terrorism instruments (which differ to the notion of 'universal' jurisdiction, which is something different and is discussed below), States parties are expected to ensure that their domestic judicial systems are capable of trying certain offences committed under certain circumstances (based on grounds such as the place of commission, nationality of the offender, etc.). This is important since, despite the Security Council and wider international community regarding terrorist activities as posing a signficant threat to international peace and security, there are currently no international criminal courts or tribunals with dedicated jurisdiction over the treaty-based crimes of the universal instruments against terrorism; such a proposition was rejected during the later negotiations on the 1998 Rome Statute when determining the jurisdiction of the International Criminal Court, even though the original intent had been for the court to prosecute such crimes as international terrorism and drug offences. This means that the ability to prosecute terrorist offences must be provided for in national criminal justice systems, whether or not this leads to a State actually carrying out a criminal prosecution or trial. Without adequate domestic capacity to discharge that duty, international counter-terrorism efforts could certainly fail although such capacity issues are, at least to some extent, mitigated by the principle of prosecute or extradite embedded within the universal counter terrorism instruments.

There can be differing approaches to the issue of immunity from criminal jurisdiction for State officials in relation to the alleged commission of international crimes such as genocide, crimes against humanity as well as war crimes. For instance, under article 27 of the 1998 Rome Statute of the International Criminal Court, there is no immunity in such circumstances; whereas the International Court of Justice has expressed a different view, such as in the Case Concerning the Arrest Warrant of 11 April 2000  discussed below.

Establishment of jurisdiction under the universal counter terrorism instruments

It would not be sufficient for States parties to the universal counter terrorism instruments to simply criminalize the conduct set forth therein. Provisions also need to be made with regard to which court or courts, in which State(s), are competent to prosecute the alleged perpetrators of terrorism-related offences. The main aim of the universal instruments is to ensure that as many States parties as is possible are competent to prosecute alleged terrorists, in order to deny terrorists safe havens and resultant impunity.

One potential risk with this approach is that a number of States parties may simultaneously assert their competence to prosecute. This situation is known as a positive conflict of jurisdiction. Short of creating a strict binding mechanism to address this type of situation, some treaties, such as the International Convention for the Suppression of the Financing of Terrorism, encourage States parties to coordinate action to fulfil this purpose. It is not stated how coordination should be carried out, or criteria provided to determine which State should exercise jurisdiction. This type of provision aims to offer a general framework for cooperation, leaving States parties with ample room to manoeuvre, and to decide whether to prosecute or extradite a suspect.

There are a number of different bases of jurisdiction for States. When an offence covered by the instruments is committed in the territory of a certain State, it is usually clear that this State should prosecute. This type of jurisdiction is based on the 'territoriality principle': States generally must not tolerate the use of their territory for criminal or terrorist purposes. Thus, when the instruments require States to establish their competence over offences committed on their territory, this requirement coincides with what all States already do in practice. As an extension of the territoriality principle, it is expected that States are able to prosecute offences committed on board vessels and aircrafts registered by them.

However, many of the universal counter terrorism instruments go further than the territoriality principle and require that States are able to prosecute certain offences committed outside of their territory by their own nationals, regardless of the place of commission. This type of jurisdiction is based on the 'active nationality principle, where a State asserts jurisdiction over a criminal offence committed outside its territory by one of its nationals.  Alternatively, under the 'passive nationality' principle, a State asserts jurisdiction over a criminal offence committed outside its territory when its nationals are among the victims of the terrorism-related crime.

Additional extraterritorial grounds for jurisdiction are set forth in specific instruments only. For example, the International Convention against the Taking of Hostages mandates State parties to establish jurisdiction over the proscribed conducts when these are committed in order to compel their Government to do or abstain from doing any act. As a general principle: "While jurisdiction to prescribe can be extraterritorial, jurisdiction to enforce is strictly territorial. A State may not enforce its criminal law in the territory of another State without the latter's consent." (O'Keefe, 2004, p. 740; there can be exceptions, however, such as the interception of weapons of mass destruction). As such, jurisdiction to prescribe and jurisdiction to enforce are technically independent of each other, although in practice they are interrelated.

Universal jurisdiction

Of the different legal bases for establishing jurisdiction, undoutedly the most politically sensitive and contentious one is that of universal jurisdiction. In essence, the concept of universal jurisdiction provides that States have the capacity to assert jurisdiction over certain alleged grave crimes, regardless of the place of their alleged commission, or the nationality of the perpetrator, etc. The sensitivities associated with universal jurisdiction are not assisted by the fact that the exact meaning and parameters of the term are unclear. As ad hoc Judge Van den Wyngaert observed in her dissenting opinion in the Arrest Warrant case:

"There is no generally accepted definition of universal jurisdiction in conventional or customary international law", noting that: "Many views exist as to its legal meaning" and that "uncertainties ... may exist concerning the definition [of the concept]" (paras. 44-46).

While the UN's 19 counter terrorism instruments, known as universal (they are open to adoption and accession by all UN Member States), oblige States parties to establish criminal offences and legal jurisdiction (often referred to as "extraterritorial jurisdiction") for certain acts beyond their territories, this does not extend to universal jurisdiction, as the term is generally understood. Under the instruments, in order to establish jurisdiction over crimes committed outside their territories, certain specified links must exist before a State party can assert jurisdiction over criminal offences whioch are alleged to have occurred beyond their territories (e.g. one of their nationals is an alleged perpetrator, or a victim). Moreover, the instruments generally adopt a measure short of the universality principle, embodied by the aut dedere aut judicare principle, which provides that whenever a person accused of a specified crime is present on a State's territory, that State must investigate and either prosecute that person or extradite the accused to another requesting State.

By comparison, under 'the universality principle', a State acquires jurisdiction over a certain offence even if there is no link with the State itself, solely because the alleged offence is perceived as being so grave that it cannot go unpunished. The principle is utilized by the 1949 Geneva Conventions for perpetrators of "grave breaches" alone, which is a small sub-set of the most serious war crimes.  Such jurisdiction can exist for core international crimes too, whether sourced in customary international law and/or in international treaties such as the 1949 Geneva Conventions and the 1984 Convention against Torture. This form of jurisdiction is premised on the fundamental idea that those guilty of the most egregious crimes should not escape justice.

There can be national variations regarding if and how universal jurisdiction is provided for within domestic legal systems. When a provision is made, this tends to take one of two forms. The first is the narrow notion known as the "conditional universal jurisdiction". Under this approach, the ability of a State to prosecute an accused person is conditional on the suspect having been apprehended and being physically present on the State's territory. This approach exists under customary international law, e.g., in relation to crimes of piracy, crimes against humanity, most war crimes, genocide and torture. (See e.g. Schachter, 1991; Scharf, 2001). It has been found to exist as well in relation to a number of international crimes contained in treaty instruments, notably for the commission of most war crimes arising out of the four Geneva Conventions 1949 and their Additional Protocol I of 1977, the commission of torture (article 7 of the 1984 Convention against Torture), and as specified under universal instruments against terrorism as described earlier. Notably too, as part of the implementation process of the 1998 Rome Statute, a number of States enacted universal jurisdiction legislation in relation to its core crimes of genocide, crimes against humanity and war crimes which they did not have previously. (See e.g. International Crimes and International Criminal Court Act 2000 (New Zealand); and Crimes against Humanity and War Crimes Act 2000 (Canada)).

The other form is the broad notion, also known as "absolute universal jurisdiction". In contrast with the narrow notion, this approach does not require the physical apprehension or even the physical presence of the accused person within the State for the latter to be able to prosecute the suspect. It has also been found to exist for far fewer international treaty crimes, notably for the commission of the subset of the most serious war crimes termed "grave breaches" of the 1949 Geneva Conventions and their Additional Protocol I (see e.g. the Arrest Warrant case, where jurisdiction pursuant to international arrest warrant refused on grounds of immunity). In practice, however, since many domestic legal systems do not permit in absentia legal proceedings, the accused person will need to be physically in the prosecuting State's territory before trial proceedings may begin, though preliminary work such as criminal investigation and the gathering of evidence can commence without the physical presence of the suspect.

Notably, universal jurisdiction in its "purest" form (i.e. exercised absent any nexus to the nationality of the accused or that of the victims, the territory on which the crimes were committed, or the nationality of the victims) has been heavily criticized and States have at times changed their laws to account for the concept's inherent flaws (e.g., Belgium, Spain and England have all narrowed their universal jurisdiction laws in recent years) (see Yee, 2011). Indeed, in the International Court of Justice Arrest Warrant case of 2000 noted earlier, the Court asked Belgium to cancel the arrest warrant issued by a Belgium court against the former Democratic Republic of the Congo Foreign Minister Yerodia (at para. 73)

Significantly, this means that any terrorism-related crimes, which cross the threshold of core international crimes, such as war crimes and crimes against humanity, may attract universal jurisdiction on many levels and could be prosecuted by any State, which has adopted "universal" jurisdiction within its national law.

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