Immunity from prosecution (international law)
Immunity from prosecution is a doctrine of international law that allows an accused to avoid prosecution for criminal offences. Immunities are of two types. The first is functional immunity, or immunity ratione materiae. This is an immunity granted to people who perform certain functions of state. The second is personal immunity, or immunity ratione personae. This is an immunity granted to certain officials because of the office they hold, rather than in relation to the act they have committed.
Functional immunity arises from customary international law and treaty law and confers immunities on those performing acts of state (usually a foreign official). Any person who in performing an act of state commits a criminal offence is immune from prosecution. This is so even after the person ceases to perform acts of state. Thus it is a type of immunity limited in the acts to which it attaches (acts of state) but will only end if the state itself ceases to exist. This type of immunity is based on respect for sovereign equality and state dignity.
The offices usually recognised as attracting this immunity are Head of State or Head of Government, senior cabinet members, Foreign Minister, and Defence Minister. Such officers are immune from prosecution for everything they do during their time in office. For example, an English court held that a warrant could not be issued for the arrest of Robert Mugabe on charges of international crimes on the basis that he was a presently serving Head of State at the time the proceedings were brought. Other examples are the attempts to prosecute Fidel Castro in Spain and Jiang Zemin in the USA.
However, the moment accused leaves office, they are liable to be prosecuted for crimes committed before or after their term in office, or for crimes committed whilst in office in a personal capacity (subject to jurisdictional requirements and local law). Pinochet was only able to come to trial because Chile and the UK had both signed and ratified the UN Convention Against Torture through which such immunities were waived.
It may be the case that functional immunity is itself being eroded. In 2004 the Appeals Chamber of the Special Court for Sierra Leone held that indicted Liberian president Charles Taylor could not invoke his Head of State immunity to resist the charges against him, even though he was an incumbent Head of State at the time of his indictment. However, this reasoning was based on the construction of the court's constituent statute, that dealt with the matter of indicting state officials. In any case, Taylor had ceased to be an incumbent Head of State by the time of the court's decision so the arresting authorities would have been free to issue a fresh warrant had the initial warrant been overturned. Nevertheless, this decision may signal a changing direction in international law on this issue.
Recent developments in international law suggest that this type of immunity, whilst it may be available as a defence to prosecution for local or domestic crimes or civil liability, is not a defence to an international crime. (International crimes include crimes against humanity, war crimes, and genocide). This has developed in the jurisprudence of the International Criminal Tribunal for the Former Yugoslavia, particularly in the Karadzic, Milosevic, and Furundzija cases (though care should be taken when considering ICTY jurisprudence due to its Ad-hoc nature). This was also the agreed position as between the parties in their pleadings in the International Court of Justice Case Concerning the Arrest Warrant of 11 April 2000 (Democratic Republic of the Congo v. Belgium). The reasons commonly given for why this immunity is not available as a defence to international crimes is straight forward: (1) that is genocide, war crimes and crimes against humanity are not acts of state. Criminal acts of the type in question are committed by human actors, not states; and (2) we cannot allow the jus cogens nature of international crimes, i.e. the fact that they are non-derogable norms, to be eroded by immunities.
However, the final judgment of the ICJ regarding immunity may have thrown the existence of such a rule limiting functional immunities into doubt. See in this respect the criticism of the ICJ's approach by Wouters, Cassese and Wirth among others, though some such as Bassiouni claim that the ICJ affirmed the existence of the rule.
Regarding claims based on the idea that a senior state official committing International crimes can never be said to be acting officially, as Wouters notes “This argument, however, is not waterproof since it ignores the sad reality that in most cases those crimes are precisely committed by or with the support of high-ranking officials as part of a state’s policy, and thus can fall within the scope of official acts.” Academic opinion on the matter is divided and indeed only the future development of International Customary law, possibly accelerated by states exercising universal jurisdiction over retired senior state officials, will be able to confirm whether state sovereignty has now yielded partially to internationally held human rights values.
In November 2007, French prosecutors refused to press charges against former US Secretary of Defense Donald Rumsfeld for torture and other alleged crimes committed during the course of the US invasion of Iraq, on the grounds that heads of state enjoyed official immunity under customary international law, and they further claimed that the immunity exists after the official has left office.
- See also Diplomatic immunity
This type of immunity arises from customary international law and confers immunity on people holding a particular office from the civil, criminal, and administrative jurisdiction. This immunity is extended to diplomatic agents and their families while posted abroad (and is also valid for their transfer to or from that post, and is only valid for the country to which they are posted). Under personal immunity, private residence, papers, correspondence, and property of an official enjoying personal immunities are inviolable.
According to Cassese (2005), personal immunities are extended to cover personal activities of an official, including immunity from arrest and detention (though the host state may declare the person persona non grata), immunity from criminal jurisdiction, immunity from the civil and administrative jurisdiction of the host state. No immunities hold for private immoveable property unless held on behalf of the sending state for the purposes of the mission, issues of succession, professional or commercial activity exercised outside of official functions, or where the official has voluntarily submitted to the proceedings. Example in the case of Miles Agha, Mazen Agha who is currently residing in Dallas TX. Personal immunities cease with the cessation of the post.
This type of immunity is not for the official’s personal benefit but is based on the need for states to function effectively and hence not be deprived of their most important officials: Arrest Warrant Case.
Cases of overlap
When a person, who enjoys a personal immunity and has committed a criminal act covered also by functional immunity, leaves office, the personal immunity is removed as usual. This is what happened in the Pinochet case before the House of Lords. Senator Pinochet was only able to be extradited to face charges that were not caught by the functional immunity (and also met the separate tests for extradition under English law).
- Amnesty law
- Command responsibility
- Diplomatic immunity
- International law
- State immunity
- see the Arrest Warrant Case, Pinochet Case (R v Bow Street Magistrates; ex parte Pinochet Ugarte (No 3)  1 AC 147, House of Lords)
- Mugabe, reported at (2004) 53 ICLQ 789
- French prosecutors throw out Rumsfeld torture case, Reuters Fri Nov 23, 2007
- "French prosecutors throw out Rumsfeld torture case". Reuters.com. November 23, 2007.
- In Re Pinochet (1999) 93 AJIL 690
- R v Bow Street Magistrates, ex parte Pinochet (Nos 1 & 3),  1 AC 147
- Arrest Warrant of 11 April 2000 Case (Democratic Republic of the Congo v Belgium), ICJ Rep, 2002
- Akande, “International Law Immunities and the International Criminal Court”, (2004) 98 AJIL 407
- Cassese, International Criminal Law (OUP, Oxford 2003), Chapter 14
- Cassese, “When May Senior State Officials be Tried for International Crimes? Some Comments on the Congo v. Belgium Case”, (2002) 13 EJIL 853
- Fox, The Law of State Immunity, (OUP, Oxford 2003), Chapter 12
- Warbrick, “Immunity and International Crimes in English Law”, (2004) 53 ICLQ 769