Legal Definitions - double criminality

Double criminality is a fundamental principle in international law, particularly relevant to the process of extradition. It means that for a country to extradite an individual to another country, the alleged act for which the person is sought must be considered a criminal offense in *both* the requesting country and the country where the person is currently located.

In essence, if an act is deemed a crime in Country A but is not recognized as a crime under the laws of Country B, then Country B will generally refuse to extradite the individual to Country A for that specific act. This principle ensures that a country does not assist in prosecuting someone for an act that it does not itself consider illegal.

Here are some examples to illustrate this concept:

• Example 1: International Financial Fraud

  Imagine a person commits a large-scale financial fraud in Germany, causing significant losses to investors, and then flees to the United States. German authorities issue an international arrest warrant and formally request the United States to extradite the individual to stand trial in Germany. Since financial fraud is a serious criminal offense under the laws of both Germany and the United States, the requirement of double criminality is met. This means that the U.S. can proceed with the extradition process, as the alleged act is considered a crime in both nations.

• Example 2: Differing Laws on Political Speech

  Consider an individual who is wanted by Country A for "insulting the head of state," an act that is a severe criminal offense in Country A. This person then travels to Country B, where such speech, while potentially controversial, is protected under robust free speech laws and is not considered a criminal act. If Country A requests extradition from Country B, Country B would likely deny the request based on the principle of double criminality. The alleged act, though criminal in Country A, is not a crime under Country B's jurisdiction, thus failing the double criminality test.

• Example 3: Evolving Drug Laws

  Suppose a person is wanted by Country X for possessing a significant quantity of a specific substance, which is classified as a serious felony in Country X. This individual is later located in Country Y, where that same substance has been legalized for recreational use, and possessing that quantity is no longer a criminal offense. If Country X requests extradition, Country Y would likely refuse. The reason is that while the act is criminal in Country X, it is not considered a crime in Country Y, thereby failing the double criminality requirement for extradition.