International Criminal Law

International criminal law also consists of procedures for cooperation between states in the execution of their national criminal law.

Under international law, one state cannot exercise its jurisdiction on the territory of another without the agreement of that state. This means that when suspects or evidence relating to a criminal trial in one country are found on the territory of another, cooperation between them is often indispensable. The most common, and most important, of these cooperative procedures are extradition and mutual legal assistance in cases of criminal law. Other important procedures include the transfer of prisoners, the seizure and forfeiture of the illicit proceedings of crime, the recognition of foreign penal judgments, and the transfer of penal proceedings.

Extradition. Extradition is by far the most important of these cooperative procedures. When a person charged with a criminal violation of the law in one state is physically present on the territory of another, it is via the extradition procedure that the former may request the surrender of the accused from the latter. There is no general obligation of states to extradite under international law, and treaties, bilateral or multilateral, provide the basis for extradition in almost all cases. Extradition treaties establish the reciprocal agreement of the states-parties to extradite, set out the procedures for requesting extradition, and outline the conditions under which it may be granted or refused.

These treaties define a range of extraditable offenses. To form the basis of a request for extradition, an offense must generally be punishable under the laws of both countries. This is known as the principle of double-criminality. Among the more controversial provisions commonly found in these treaties is the traditional rule that no person should be extradited for a political offense. This rule severely complicated efforts by the United Kingdom to extradite accused terrorists from the United States until a 1985 US-UK Supplementary Extradition Treaty clarified that such offenses were not to be regarded as offenses of a political nature.

States choose their extradition partners carefully, and need not enter into such treaties with a country if they lack faith in its judicial system. In Europe, a multilateral extradition treaty has been successful in creating a regional regime of extradition. Supplementing bilateral and multilateral extradition treaties are provisions appearing in various multilateral treaties on subjects such as hijacking and the drug traffic, which may also serve as the legal basis for the extradition process. These generally incorporate the obligation to extradite or prosecute, as discussed elsewhere in this entry.

In one prominent 1992 case, the U.S. Drug Enforcement Administration (DEA) attempted to circumvent extradition procedures by kidnapping a suspect in Mexico and bringing him directly to trial in the United States. Mexico strongly objected, arguing that this act violated Mexican sovereignty as well as the U.S.-Mexico extradition treaty. Lawyers for the accused, a Mexican national named Hector Alvarez-Machain, argued that his abduction violated the extradition treaty and that, as a result, he could not be legally tried in the United States. The U.S. Supreme Court, in a very controversial opinion (United States v. Alvarez-Machain, 504 U.S. 655 (1992)), ruled 6–3 that the fact of his forcible abduction did not prohibit his trial in a United States court for violations of this country's criminal laws. The decision was based in part on their finding that "the Treaty says nothing about either country refraining from forcibly abducting people from the other's territory or the consequences if an abduction occurs." Mexico, and a number of other countries, reacted by expressing their desire to include an explicit ban on forcible abduction in their extradition treaties. In response, the U.S. government announced that, in the future, it would not be the policy of the U.S. to carry out such forcible abductions in lieu of extradition.

Mutual legal assistance. Technically extradition is a form of mutual legal assistance, but the term generally refers to mechanisms for the securing of evidence from a foreign state. This was traditionally done by means of letters rogatory (requests by the court of one country for evidence to be taken by the court of another country), which left cooperation within the discretion of the requested state. To remedy this problem, the United States has entered into several bilateral conventions that make the execution of such requests by the treaty partners a matter of course.