Extradition law is essentially governed by individual treaties put in place between nations. Although exceptions to extradition may vary from treaty to treaty, there is a fair amount of overlap and an exhaustive list of what may be considered as the most common exceptions to extradition.
Nationality
Political offenses. These provisions are aimed at crimes such as treason, espionage, and other offenses that could be used to target political opponents or otherwise cause the requested state to become entangled in the domestic politics of the requesting state. To clarify and limit the contours of the “political offense” exception, most U.S. bilateral treaties now exempt violent conduct such as bombings and hostage-taking from the exception, even if the individual sought for extradition asserts that the conduct in question was political in nature.
Nationality. Many countries refuse to extradite their own nationals, and where that position prevails in negotiations, an extradition treaty may include an exception for this policy. The U.S. government has long held the view that nationality should not operate as a bar to extradition, since the requesting state should have the right to pursue criminal charges against persons who violate its laws regardless of nationality. The U.S. government accordingly extradites its nationals and seeks to limit nationality-based denials of its outgoing requests. In addition, U.S. statutory law expressly permits the Secretary of State to surrender a U.S. citizen to a foreign country when the extradition judge has issued a certification of extraditability and “the other requirements of [the applicable] treaty or convention are met.”
Prior proceedings (non bis in idem). These provisions, which appear in most extradition treaties, bar extradition where the person has already been convicted or acquitted in the requested state of the offense for which extradition is requested. The concept is similar to the U.S. doctrine of “double jeopardy.”
Capital offenses. Although the United States tries to limit the application of this exception in its bilateral extradition treaties, many treaties contain provisions permitting the requested state to demand assurances that the death penalty will not be sought or imposed. For example, the U.S.-South Africa treaty provides that “[w]hen the offence for which extradition is sought is punishable by death under the laws in the Requesting State, and is not punishable by death under the laws in the Requested State, the Requested State may refuse extradition unless the Requesting State provides assurances that the death penalty will not be imposed, or if imposed, will not be carried out.”
Rule of specialty. The doctrine of specialty provides that “the requesting state may, after the fugitive has been surrendered to it, prosecute or punish the fugitive only for the crime or crimes for which extradition was granted, subject to certain exceptions.” A common modern formulation of this doctrine, as explained by the U.S. Senate Committee on Foreign Relations in its report on the U.S. extradition treaty with Cyprus, is that “a person extradited under the Treaty may only be detained, tried, or punished in the Requesting State for: (1) the offense for which extradition was granted or a differently denominated offense based on the same facts, provided the offense is extraditable or is a lesser included offense; (2) an offense committed after the extradition; or (3) an offense for which the executive authority of the Requested State consents.”
Procedural and documentation requirements. Extradition treaties generally contain provisions that specify the documents and information required to support an extradition request, along with any translation and authentication requirements. Typically, the requesting state must provide information about the identity of the person sought (including specific descriptive information); the text of relevant laws; information about the facts and procedural history of the case; documentation relating to the charges or convictions; and any other information the parties have deemed necessary to evaluate the request. With respect to requests for extradition for a person sought from the United States, U.S. extradition judges have interpreted U.S. extradition treaties and statutory law as requiring evidence sufficient to, at minimum, support a finding of “probable cause” that the person is guilty of the charges pending in the requested state.
Statute of limitations. Because statutes of limitations for particular offenses vary by country, many treaties include provisions specifying which country’s statute of limitations will apply or, in some cases, providing that the passage of time is no bar to extradition. U.S. extradition treaties typically provide that the statute of limitations in the requesting state should be the only relevant limit.
