Extradition under International Law: Principles, Procedure and Grounds for Refusal

Extradition under international law concerns the formal surrender of a person by one State to another State for criminal prosecution or for the enforcement of a sentence. It becomes necessary when a person accused or convicted of an offence is found outside the territory of the State that wishes to prosecute or punish that person.

The basic idea is straightforward, but the law is not. Extradition involves the sovereignty of two States, domestic criminal procedure, treaty obligations and the rights of the person whose surrender is requested. Questions may arise about double criminality, political offences, nationality, previous trials, limitation periods, torture, the death penalty, refugee protection and the fairness of the proceedings in the requesting State.

In brief: there is no single universal extradition code governing every country. Extradition normally operates through bilateral treaties, multilateral conventions and domestic legislation. Some States require a treaty before surrender can take place, while others permit extradition on another legal basis, including reciprocity or domestic legislation. The applicable law must therefore be identified before deciding whether a particular person can be extradited.

Extradition is also a useful example of the practical operation of treaties and other sources of international law. International obligations may arise from a treaty, but courts and executive authorities ordinarily carry those obligations into effect through national law.

What is extradition?

Extradition may be described as a formal legal process through which a State in whose territory a person is found surrenders that person to another State that seeks him or her for prosecution or for the execution of a criminal sentence.

The country asking for the person is generally called the requesting State. The country in which the person is located is the requested State. The individual concerned is often described as the person sought or requested person.

Suppose a person is accused of murder in State A and leaves for State B before trial. Police officers from State A cannot ordinarily enter State B and arrest the person merely because State A has criminal jurisdiction over the alleged offence. State A must use an appropriate form of international cooperation. If extradition is available, it may formally request State B to surrender the accused.

State B does not simply accept the accusation as proof of guilt. Its authorities apply the relevant treaty and domestic law. Depending upon that law, a court, executive authority, or both may examine whether the legal requirements for extradition have been fulfilled.

Extradition may also be requested after conviction. A person who has been convicted and sentenced but escapes before completing the sentence may be sought for the purpose of enforcing that sentence.

Why is extradition needed?

Criminal jurisdiction and enforcement jurisdiction are not the same thing. A State may have legal authority to prosecute conduct but ordinarily cannot exercise police powers freely within the territory of another sovereign State.

Without international cooperation, crossing a border could provide offenders with an easy means of avoiding prosecution or punishment. Extradition addresses that problem without allowing one State to disregard the territorial sovereignty of another.

The procedure therefore performs two functions. It facilitates criminal justice while requiring the requesting State to obtain the lawful cooperation of the State in which the person is found.

What is the legal basis of extradition?

There is no world extradition statute binding every State. The legal basis of an extradition request must be identified in the circumstances of the particular case.

Bilateral extradition treaties

Many extradition relationships are governed by bilateral treaties. These agreements commonly determine which offences are extraditable, what documents must accompany a request, what grounds permit or require refusal, whether nationals may be extradited, and what conditions apply after surrender.

The wording of the treaty is important. A principle frequently found in extradition law should not automatically be treated as an identical rule in every extradition relationship.

Multilateral conventions

A multilateral convention dealing with particular crimes may also contain extradition provisions. Article 16 of the United Nations Convention against Transnational Organized Crime, for example, contains an extensive extradition regime for offences falling within the Convention.

Article 44 of the United Nations Convention against Corruption deals with extradition in relation to Convention offences. Other treaties concerning terrorism, torture and particular forms of transnational crime contain their own rules.

Domestic extradition law

National legislation remains central to the process. Domestic law may regulate provisional arrest, detention, evidentiary requirements, court hearings, appeals, executive decisions and the actual surrender of the person.

A treaty may create an international obligation between States, while domestic legislation provides the machinery through which the requested State carries out that obligation.

The United Nations Model Treaty on Extradition

The United Nations General Assembly adopted the Model Treaty on Extradition in Resolution 45/116 of 14 December 1990 as a framework that could assist States when negotiating bilateral extradition arrangements. The Model Treaty was later complemented by provisions adopted in General Assembly Resolution 52/88 of 12 December 1997.

The Model Treaty is influential, but it is not itself a universal extradition treaty. Its provisions should not be cited as though every State is automatically bound by them.

Can extradition take place without a treaty?

Sometimes it can. The answer depends primarily upon the law of the requested State and any applicable international convention.

Some States make extradition conditional upon the existence of a treaty. Other States allow extradition without a bilateral treaty where domestic legislation permits surrender, sometimes on the basis of reciprocity.

A multilateral convention can also become relevant. UNTOC, for example, expressly distinguishes between States that require an extradition treaty and those that do not, and it permits certain States Parties to treat the Convention itself as a legal basis for extradition.

It is therefore too broad to say that extradition is impossible whenever two countries have no bilateral extradition treaty. The legislation of the requested State and any applicable multilateral instrument must also be examined.

Is there a general international duty to extradite?

There is no simple rule requiring every State to extradite every person accused of a serious crime.

An obligation to extradite usually has to be established under an applicable treaty or other legal rule. Even where a treaty applies, surrender remains subject to the conditions, procedures and grounds of refusal contained in that treaty and the relevant domestic law.

This point is particularly important when discussing serious international crimes. The existence of international criminal responsibility for particular conduct does not by itself prove that every State has an identical general duty to extradite the alleged offender.

What is an extraditable offence?

Older extradition treaties frequently listed particular offences for which extradition could be granted. Murder, kidnapping, robbery, forgery and serious fraud were typical examples.

Modern treaties often use a different approach. Instead of maintaining a fixed list, they define extraditable offences by reference to the seriousness of the conduct and the punishment available under the laws of both States.

A treaty may, for example, require that the conduct be punishable in each State by imprisonment above a specified minimum level. Where extradition is requested to enforce an existing sentence, the treaty may also prescribe a minimum portion of the sentence that remains to be served.

There is no universal minimum sentence applicable to all extradition arrangements. The relevant treaty or statute must be consulted.

The principle of double criminality

Double criminality, also called dual criminality, is one of the most familiar principles of extradition law. In general terms, the conduct for which extradition is sought must amount to an offence under the laws of both the requesting and requested States where the applicable legal instrument requires double criminality.

The principle prevents a State from being required to use its coercive powers to surrender a person for conduct that its own law does not treat as criminal.

The offences do not necessarily have to carry the same title. Nor must the criminal statutes of both States use identical language. The inquiry commonly focuses on the substance of the conduct.

For example, conduct classified as one form of fraud in the requesting State might satisfy a differently named dishonesty offence in the requested State. The important question is whether the underlying conduct meets the applicable double-criminality test.

The precise test nevertheless remains treaty- and jurisdiction-specific. It should not be assumed that every legal system applies double criminality in exactly the same manner.

The rule of specialty

The rule of specialty generally restricts the requesting State from obtaining extradition for one offence and then prosecuting the surrendered person freely for unrelated offences committed before extradition.

Suppose State A requests extradition from State B for a specified fraud offence. If State B grants extradition on that basis, State A ordinarily has to respect the terms upon which surrender was granted.

Prosecution for another pre-extradition offence may require the consent of the requested State or may be permitted under an exception contained in the applicable treaty.

Specialty protects the integrity of the extradition decision. The requesting State should not be able to secure surrender on one representation and then disregard the limits attached to it.

Previous trial and ne bis in idem

An extradition request may be barred where the person has already been finally tried for the same matter. This reflects the principle commonly expressed as ne bis in idem, or protection against being tried twice for the same matter.

Its application can be difficult. Authorities may have to determine whether the proceedings concern the same conduct, whether the previous decision was final, and whether the relevant treaty treats an acquittal, conviction, pardon or other final disposition as a bar to surrender.

The existence of the general principle does not remove the need to examine the language of the applicable extradition instrument.

The political offence exception

Political offences have historically occupied a special position in extradition law. States were reluctant to surrender individuals merely because they opposed another government or participated in genuinely political struggles.

A distinction developed between purely political offences and ordinary crimes connected in some way with political activity. The second category has always been more difficult. A violent offence does not become a protected political offence merely because the offender claims a political motive.

Modern treaty practice has considerably narrowed the political-offence exception for terrorism and certain other serious offences.

The position regarding genocide is especially clear. Article VII of the Convention on the Prevention and Punishment of the Crime of Genocide provides that genocide and the other acts listed in Article III are not to be considered political crimes for the purpose of extradition.

Other treaties likewise exclude specified crimes from treatment as political offences. It is safer, however, to identify the applicable treaty than to state that one universal political-offence rule applies to every international crime and every State.

Political persecution and discriminatory requests

A political offence should be distinguished from a politically motivated request.

Many extradition arrangements contain safeguards where there are substantial grounds for believing that an ordinary criminal charge has been used as a means of prosecuting or punishing a person because of political opinion, race, religion, nationality or another protected status.

This is a different inquiry from asking whether the offence itself is political.

A person accused of fraud does not automatically gain protection merely by being politically active. At the same time, a government cannot necessarily avoid extradition safeguards by placing an ordinary criminal label on what is actually a persecutory proceeding.

Military and fiscal offences

Some extradition treaties distinguish purely military offences from ordinary criminal offences. An offence that exists only because of a person's military status may therefore receive different treatment from conduct that is also criminal under ordinary law.

Fiscal offences were historically another area in which extradition was restricted. Modern international cooperation has reduced the importance of broad fiscal-offence exclusions.

UNTOC and UNCAC, for example, contain provisions intended to prevent extradition from being refused solely because an offence involves fiscal matters. Whether a particular tax, customs or financial offence is extraditable must still be determined under the governing legal instrument.

Can a State refuse to extradite its own nationals?

National approaches differ substantially.

Some States permit extradition of their own citizens when the normal treaty conditions are satisfied. Other States impose constitutional or statutory restrictions on surrendering nationals.

Modern international conventions often address the risk that a nationality restriction could create impunity. Where extradition is refused because the requested person is a national, the relevant convention may require the requested State to submit the matter to its own competent authorities for prosecution.

The rule does not mean that every refusal to extradite a national automatically creates universal jurisdiction. The jurisdictional basis and the precise obligation must be found in the applicable treaty and domestic law.

Limitation periods and passage of time

The passage of time can also affect extradition.

Some treaties permit or require refusal where prosecution or enforcement of the sentence has become barred by limitation. Difficult questions may arise because States do not always calculate limitation periods in the same way.

The law of one country may suspend the limitation period while the accused is a fugitive, while another legal system may apply a different rule. The treaty determines which law or combination of laws is relevant.

How much evidence is required?

An extradition proceeding is ordinarily different from the criminal trial that determines guilt.

That does not mean evidence is irrelevant. Extradition systems differ considerably in the evidential showing required from the requesting State.

Some legal systems require material capable of satisfying a specified evidentiary standard. Other treaty regimes have simplified the evidential requirements and place greater emphasis on the validity of the foreign warrant, conviction or supporting documents.

It is therefore inaccurate to say that every extradition court decides whether the accused is guilty. It is equally inaccurate to say that evidence is never considered. The function of the extradition court depends upon the governing law.

How does the extradition process work?

No single procedure applies worldwide, but a conventional extradition case commonly passes through several stages.

Locating the person

The requesting authorities must first determine where the wanted person is located. International police cooperation, immigration information and other lawful investigative mechanisms may assist in locating the person.

Provisional arrest

Where there is a risk that the person will flee before the complete extradition papers can be prepared, a treaty may allow the requesting State to seek provisional arrest.

Provisional arrest is temporary. It does not itself decide the extradition request. The full request must ordinarily follow within the period prescribed by the applicable law.

The formal request

The extradition request is transmitted through the channel required by the treaty or domestic legislation. This may involve diplomatic channels, ministries, central authorities or another designated institution.

The request normally identifies the person, describes the alleged conduct, gives the applicable criminal provisions and supplies the warrant, judgment or other documents required under the governing law.

Judicial proceedings

In many States, a court determines whether the legal requirements for extradition have been satisfied. The court may examine identity, extraditability of the offence, double criminality, evidentiary requirements and statutory or human-rights bars.

The extradition hearing should not be confused with the eventual criminal trial in the requesting State.

Executive decision

Some extradition systems divide responsibility between the judiciary and the executive. A court may decide whether the person is legally eligible for extradition, after which a minister or other executive authority makes the surrender decision.

The allocation of functions varies among legal systems.

Surrender

When the available legal proceedings have concluded and extradition is authorized, the States arrange the physical surrender of the person. Conditions attached to extradition, including specialty or assurances concerning punishment, may continue to govern what happens after transfer.

What is the role of INTERPOL?

INTERPOL facilitates international police cooperation, but INTERPOL does not itself decide extradition cases.

A commonly misunderstood mechanism is the Red Notice.

According to INTERPOL, a Red Notice is a request to law-enforcement authorities worldwide to locate and provisionally arrest a person pending extradition, surrender or similar legal action.

A Red Notice is not an international arrest warrant.

The person is wanted by the requesting country or international tribunal, not by INTERPOL as an independent prosecuting authority. Each member country applies its own law when deciding what legal effect to give a Red Notice and whether an arrest can be made.

INTERPOL cannot compel a member State to arrest a person merely because a Red Notice exists.

Human rights and extradition

Extradition law cannot be separated from applicable human-rights obligations.

A treaty may provide a legal basis for extradition, but surrender may still be prohibited where another binding rule prevents the requested State from exposing the individual to certain forms of treatment.

Torture and Article 3 of the Convention against Torture

The clearest universal treaty rule is found in Article 3 of the Convention against Torture.

A State Party must not expel, return or extradite a person to another State where there are substantial grounds for believing that the person would be in danger of being subjected to torture.

This rule is important because extradition is expressly mentioned in the Convention. It is not merely an inference drawn from general humanitarian considerations.

The authorities must assess the risk faced by the particular person. The inquiry concerns whether the legal threshold under Article 3 has been met, not simply whether the requesting State has general human-rights problems.

Soering v. United Kingdom

The 1989 judgment of the European Court of Human Rights in Soering v. United Kingdom became one of the leading authorities on the relationship between extradition and protection against prohibited treatment.

The United Kingdom intended to extradite Jens Soering to the United States, where he faced capital murder charges in Virginia. The European Court examined whether the circumstances he was likely to face, particularly the so-called death-row phenomenon, would expose him to treatment contrary to Article 3 of the European Convention on Human Rights.

The Court concluded that extradition in the circumstances would engage the United Kingdom's responsibility under Article 3.

The decision should be stated carefully. Soering did not establish a rule that every extradition to a country retaining the death penalty is automatically unlawful under international law. The judgment arose under the European Convention and turned on the anticipated treatment and circumstances facing the applicant.

Extradition and the death penalty

Capital punishment creates particular difficulty where the requesting State retains the death penalty and the requested State has abolished it or is otherwise legally prohibited from exposing a person to execution.

There is no single universal extradition rule under which every State must refuse surrender whenever capital punishment is legally available in the requesting State.

Depending upon the requested State's law and treaty obligations, extradition may be refused or made conditional upon assurances that the death penalty will not be imposed or, if imposed, will not be carried out.

The reliability and legal effect of any assurance must be evaluated under the law governing the particular case.

Extradition, refugees and non-refoulement

Extradition may also intersect with refugee law.

Article 33 of the 1951 Refugee Convention contains the principle of non-refoulement. In general terms, a refugee must not be returned to a territory where his or her life or freedom would be threatened for a Convention reason, subject to the qualifications contained in the Convention.

UNHCR has consistently treated non-refoulement as relevant to extradition and other forms of forcible removal. A State should therefore not assume that calling a transfer “extradition” removes its refugee-law obligations.

Refugee protection and the Convention against Torture should nevertheless be kept legally distinct.

The Refugee Convention contains qualifications, including Article 33(2), and some persons may be excluded from refugee status under Article 1F. Article 3 of the Convention against Torture creates a separate prohibition where the required danger of torture exists. A person who cannot rely upon refugee status may therefore still have a separate claim under applicable human-rights law.

Nor does refugee law provide immunity from prosecution for ordinary crime. The question is whether surrender to the particular destination is lawful, not whether the person can never be prosecuted.

Diplomatic assurances

A requesting State may sometimes provide assurances intended to address a legal obstacle to extradition.

An assurance might concern the death penalty, detention conditions, prosecution only for specified offences, or another matter relevant to surrender.

The mere existence of an assurance does not necessarily resolve the legal issue. Its adequacy may depend upon the nature of the risk, the precision of the undertaking, the requesting State's ability and willingness to comply, previous practice and any available monitoring mechanism.

The controlling question remains whether extradition would comply with the requested State's legal obligations.

What does aut dedere aut judicare mean?

The expression aut dedere aut judicare is commonly used to describe an obligation to extradite or prosecute.

The expression must be used carefully. It does not establish a universal rule automatically applicable to every crime merely because the words are Latin or because the alleged conduct is serious.

Numerous multilateral treaties contain extradite-or-prosecute provisions, but their wording and operation differ.

The International Law Commission completed its work on the topic in 2014. Its final report examined the extensive treaty practice and the question whether a broader customary rule exists. The Commission did not settle the matter by declaring that one general customary obligation applies universally to all serious crimes. It expressly avoided treating the existence of criminal prohibitions as automatically proving a corresponding customary obligation to extradite or prosecute.

For legal writing, the safer method is therefore to identify the treaty or other rule from which the particular obligation arises.

The Convention against Torture and the duty to submit a case for prosecution

The Convention against Torture provides an important example.

Article 7 requires a State Party in whose territory an alleged offender is found, in the circumstances contemplated by the Convention, to submit the case to its competent authorities for the purpose of prosecution if it does not extradite that person.

This does not mean that conviction is compulsory. The competent authorities must make their decision in the same manner as in an ordinary case of a serious offence under the law of that State.

The important point is that the duty to submit the case cannot simply be avoided by doing nothing.

Belgium v. Senegal: how the rule operates

The International Court of Justice considered this issue in Questions relating to the Obligation to Prosecute or Extradite (Belgium v. Senegal), decided on 20 July 2012.

The proceedings concerned former Chadian President Hissène Habré, who was living in Senegal and was accused of serious acts of torture committed during his rule.

Belgium relied upon the Convention against Torture and sought Habré's extradition. The International Court of Justice examined Senegal's obligations under the Convention.

The Court held, among other things, that Senegal had failed to fulfil its obligation under Article 7(1) to submit the case to its competent authorities for prosecution.

An important aspect of the judgment is the relationship between prosecution and extradition under the Convention. The obligation to submit the case for prosecution is not dependent upon a prior extradition request. Extradition is an option available within the Convention regime; the State cannot simply leave the alleged offender unprosecuted merely because no extradition has taken place.

The case demonstrates why aut dedere aut judicare must be examined within the particular treaty from which the obligation arises rather than treated as an undefined universal slogan.

Extradition and asylum are different

Extradition and asylum may arise in the same factual situation, but they answer different legal questions.

Extradition asks whether one State may or must surrender a person to another State for criminal proceedings or punishment.

Asylum and refugee law concern international protection against persecution and unlawful return.

Applying for asylum does not automatically defeat a genuine extradition request. Conversely, an extradition request cannot be used to avoid a State's applicable non-refoulement obligations.

The requested State may therefore have to consider extradition law and international protection law at the same time.

Extradition and deportation

Extradition should also be distinguished from deportation.

Extradition ordinarily takes place because another State seeks a person for criminal prosecution or punishment. Deportation ordinarily arises from immigration law because a person is liable to removal from the State in which he or she is present.

The powers, procedures and legal safeguards may therefore differ.

The distinction does not mean that governments are free to use immigration procedures merely to evade legal protections that would otherwise apply to a criminal transfer.

Extradition and rendition

“Rendition” is sometimes used broadly to describe the transfer of a person from one jurisdiction to another.

The expression “extraordinary rendition,” however, became associated particularly with transfers carried out outside ordinary judicial extradition procedures in the context of counter-terrorism operations.

Such a transfer should not be treated as legally equivalent to extradition. Formal extradition is conducted through an established legal process. A transfer outside that process may raise independent questions concerning sovereignty, arbitrary detention, torture and other international obligations.

Extradition and mutual legal assistance

Mutual legal assistance and extradition are related forms of international criminal cooperation but they perform different functions.

Extradition concerns the transfer of a person.

Mutual legal assistance concerns cooperation in obtaining evidence or carrying out investigative and judicial measures. A State may seek bank records, witness evidence, search and seizure assistance, asset information or other evidence from another country without asking for the surrender of a suspect.

Both mechanisms may be used in the same investigation.

Extradition and surrender to an international criminal court

Extradition between States should also be distinguished from surrender to an international criminal court.

The Rome Statute of the International Criminal Court expressly distinguishes “surrender” from “extradition.” In the Statute's terminology, surrender concerns delivery of a person by a State to the Court, while extradition concerns delivery of a person by one State to another under treaty, convention or national legislation.

This distinction matters when discussing the International Criminal Court. A request from the ICC is governed by the Rome Statute and applicable implementing law rather than simply being an ordinary bilateral extradition request.

Is an INTERPOL Red Notice enough for extradition?

No.

A Red Notice may assist in locating a person and, depending upon national law, may support provisional arrest. It does not itself replace the extradition request, treaty requirements, judicial proceedings or other domestic procedures required for surrender.

Nor does a Red Notice establish that the person is guilty of the alleged offence.

The requesting country must still pursue the legal mechanism necessary to obtain extradition.

When can extradition be refused?

The answer depends upon the applicable treaty and domestic legislation.

Recurring grounds include failure to satisfy double criminality, the political character of an offence under the relevant treaty, discriminatory or persecutory prosecution, a previous final trial for the same matter, limitation rules, nationality restrictions, purely military offences, insufficient seriousness, failure to provide required documents or evidence, and applicable human-rights restrictions.

Some grounds are mandatory under a particular treaty, meaning extradition must be refused. Others are discretionary and allow the requested State to decide whether surrender should occur.

Refusal does not necessarily amount to a declaration that the person is innocent. The criminal allegations and the legal permissibility of extradition are different questions.

What happens if extradition is refused?

The consequences depend upon the reason for refusal and the governing legal framework.

A requesting State may sometimes correct a procedural defect, submit additional documents, provide an assurance or pursue an available appeal.

In other circumstances, the requested State may itself have jurisdiction to prosecute. Certain treaties require the matter to be submitted to domestic authorities where surrender does not take place.

A refusal based on a human-rights risk may also prevent transfer to the particular requesting State without necessarily preventing lawful prosecution elsewhere.

Extradition in modern international criminal cooperation

International mobility has made extradition increasingly important. A person may commit an offence in one country, hold assets in another, communicate through systems located elsewhere and reside in a fourth jurisdiction.

Extradition now operates alongside mutual legal assistance, asset recovery, international police cooperation, transfer of sentenced persons and cooperation with international criminal tribunals.

These mechanisms are especially relevant to organized crime, corruption, terrorism, cybercrime, trafficking and other offences that frequently cross national borders.

Greater international cooperation does not remove legal safeguards. The existence of a serious allegation does not permit States to disregard the requirements of the applicable treaty, domestic law or binding human-rights obligations.

Conclusion

Extradition under international law is the formal legal process through which one State seeks the surrender of a person from another State for prosecution or for the enforcement of a criminal sentence.

Its legal basis is usually found in bilateral extradition treaties, multilateral conventions and domestic legislation. There is no single universal extradition procedure, and apparently familiar principles must often be applied through the wording of a particular treaty.

Double criminality, specialty, ne bis in idem, political-offence rules, nationality restrictions and limitation periods frequently shape extradition proceedings. Modern law also requires close attention to the treatment the requested person may face after surrender.

Article 3 of the Convention against Torture provides a particularly clear rule against extradition where there are substantial grounds for believing that the person would be in danger of torture. Refugee non-refoulement, regional human-rights law and other applicable protections may impose further restrictions.

The law also distinguishes extradition from related mechanisms. A Red Notice is not an international arrest warrant; deportation is principally an immigration measure; mutual legal assistance concerns evidence rather than surrender; and transfer to the International Criminal Court is treated as surrender rather than ordinary State-to-State extradition.

The result is a system in which States cooperate against cross-border crime while retaining legal control over the circumstances in which a person may be removed from their territory. Whether extradition is lawful in a particular case ultimately depends upon the specific treaty, the requested State's domestic law and any other international obligations that apply.

Primary authorities and further reading

The law of extradition is drawn from treaties, domestic legislation and other applicable rules of international law. Readers who wish to examine the subject in greater depth may consult the following primary authorities and institutional materials:

• United Nations Model Treaty on Extradition — adopted by the UN General Assembly in Resolution 45/116 of 14 December 1990, with complementary provisions adopted in Resolution 52/88 of 12 December 1997. It provides a model framework for extradition treaties but is not itself a universal extradition convention.
• United Nations Convention against Transnational Organized Crime — Article 16 contains detailed provisions governing extradition in relation to offences covered by the Convention.
• United Nations Convention against Corruption — Article 44 deals with extradition for offences falling within the Convention.
• Convention against Torture and Other Cruel, Inhuman or Degrading Treatment or Punishment — Article 3 prohibits extradition where there are substantial grounds for believing that the person would be in danger of torture. Articles 7 and 8 are also relevant to prosecution and extradition obligations concerning offences under the Convention.
• Convention on the Prevention and Punishment of the Crime of Genocide — Article VII provides that genocide and the other acts listed in Article III are not to be regarded as political crimes for the purpose of extradition.
• International Law Commission, Final Report on the Obligation to Extradite or Prosecute (aut dedere aut judicare) — the Commission's 2014 work examines treaty practice and the legal questions surrounding extradite-or-prosecute obligations.
• Questions relating to the Obligation to Prosecute or Extradite (Belgium v. Senegal) — the International Court of Justice's 2012 judgment provides an important interpretation of Senegal's obligations under the Convention against Torture.
• Soering v. United Kingdom — the 1989 judgment of the European Court of Human Rights remains an important authority on extradition where surrender may expose a person to treatment contrary to Article 3 of the European Convention on Human Rights.
• UNHCR materials on extradition and non-refoulement — useful for understanding the relationship between extradition proceedings and the protection of refugees against unlawful return.
• INTERPOL materials on Red Notices — these explain the nature and legal function of a Red Notice, including the important distinction between a Red Notice and an international arrest warrant.

These materials should be read together with the extradition treaty and domestic law applicable to the States concerned, since extradition rules and procedures vary considerably between jurisdictions.