Which Law Applies to Crimes Committed by Dual Citizens?

1. Introduction

Dual citizenship has become increasingly common due to migration, international marriages, investment-based citizenship programs, global mobility and large diaspora communities. As a result, dual nationality is not only a matter of citizenship law but also a significant issue in criminal law. When a person is both a Turkish citizen and a citizen of another state, several questions arise: Which country’s criminal law applies? Which court has jurisdiction? Can the person be tried in Turkey? Does a foreign judgment prevent Turkish prosecution? Can the person be extradited?

Under Turkish law, the legal term commonly used is “multiple citizenship.” Turkish Citizenship Law defines multiple citizenship as a Turkish citizen’s simultaneous possession of more than one nationality. It also defines a Turkish citizen as a person connected to the Republic of Türkiye by the bond of citizenship, while a foreigner is a person who does not have such a citizenship bond with Türkiye.

Therefore, if a dual citizen has Turkish nationality, Turkish law treats that person as a Turkish citizen, even if the person also holds another passport. Dual citizenship does not create criminal immunity. On the contrary, it may create situations where more than one state claims criminal jurisdiction over the same act.

2. If the Crime Is Committed in Türkiye, Turkish Law Applies

The first and most important question is where the crime was committed. Turkish criminal law primarily follows the principle of territoriality. Under Article 8 of the Turkish Criminal Code, Turkish law applies to crimes committed in Türkiye. A crime is deemed to have been committed in Türkiye if the act is wholly or partly committed in Türkiye or if the result occurs in Türkiye. Turkish land territory, airspace, territorial waters, Turkish ships and aircraft, and certain platforms are also included within this jurisdictional framework.

This means that the offender’s nationality is not decisive when the crime is committed in Türkiye. Whether the offender is Turkish, German, French, American or a dual citizen, Turkish criminal law applies if the offence is committed within Turkish jurisdiction.

For example, if a person who is both a Turkish and German citizen commits fraud, assault, theft, defamation, drug trafficking or another criminal offence in Istanbul, the applicable law will be Turkish criminal law. The person’s second nationality does not remove the jurisdiction of Turkish courts.

This is particularly important for cybercrime, online fraud, social media offences and cross-border financial crimes. A person may act from abroad while the criminal result occurs in Türkiye. In such cases, Turkish authorities may still have jurisdiction if the legal result of the crime occurred in Türkiye.

3. If a Turkish Dual Citizen Commits a Crime Abroad

The more complex issue arises when a dual citizen commits a crime outside Türkiye. For example, if a person who is both a Turkish and British citizen commits an offence in Germany, can Türkiye prosecute that person? The answer depends on several factors: the type of offence, the minimum penalty under Turkish law, whether the suspect is present in Türkiye, whether a foreign judgment has already been rendered, and whether prosecution is legally possible under Turkish law.

Article 11 of the Turkish Criminal Code regulates offences committed abroad by Turkish citizens. According to this provision, except for offences listed under Article 13, if a Turkish citizen commits abroad an offence punishable under Turkish law by imprisonment with a lower limit of not less than one year, and if that person is present in Türkiye, the person may be punished under Turkish law provided that no judgment has been rendered abroad and prosecution is possible in Türkiye. For offences punishable by imprisonment of less than one year, prosecution depends on the complaint of the injured party or the foreign government, and the complaint must be filed within six months from the citizen’s entry into Türkiye.

This is known as the active personality principle. A state may prosecute its own citizens for certain crimes committed abroad. For dual citizens, the key point is clear: as long as the person has Turkish nationality, Türkiye may treat the person as a Turkish citizen for the purposes of Article 11.

For instance, if a person who is both a Turkish and American citizen commits aggravated fraud in France and later comes to Türkiye, Turkish jurisdiction may arise if the legal requirements are met. However, prosecution in Türkiye is not automatic. The statutory penalty, complaint requirement, foreign proceedings and procedural conditions must be examined in detail.

4. If the Victim Is Turkish

Dual citizenship may also matter from the victim’s perspective. Article 12 of the Turkish Criminal Code regulates offences committed abroad by foreigners. If a foreigner commits abroad an offence against Türkiye, or against a Turkish citizen or a private legal entity established under Turkish law, Turkish jurisdiction may arise under certain conditions. These include the presence of the offender in Türkiye, the seriousness of the offence, the absence of a foreign judgment in certain cases, and, depending on the situation, a complaint or request by the Ministry of Justice.

This provision is particularly relevant in cases of fraud, threats, blackmail, assault, sexual offences or economic crimes committed abroad against Turkish citizens. However, if the offender also has Turkish nationality, Article 11 may become the primary provision rather than the rules applicable to foreigners.

5. Some Crimes May Be Prosecuted Regardless of Nationality

Article 13 of the Turkish Criminal Code provides a broader jurisdictional basis for certain serious crimes committed abroad, whether by a Turkish citizen or by a foreigner. These include crimes against state security, crimes against the constitutional order, torture, intentional environmental pollution, drug manufacturing and trafficking, counterfeiting, prostitution, bribery and certain offences against transportation vehicles.

This provision is highly relevant for dual citizens. If a dual citizen commits abroad an offence such as drug trafficking, bribery, counterfeiting or a crime against Türkiye’s security, Turkish law may apply depending on the specific circumstances of the case.

The central point is that nationality is not the only criterion. Turkish criminal jurisdiction depends on the place of the offence, the nationality of the offender, the nationality of the victim, the nature of the offence, the harm caused to Türkiye and the procedural requirements for prosecution.

6. Does a Foreign Judgment Matter in Türkiye?

A dual citizen may already have been investigated, prosecuted or convicted abroad for the same act. Whether Türkiye may still prosecute depends on where the crime was committed and which provision applies.

If the offence was committed in Türkiye, Article 9 of the Turkish Criminal Code provides that a person may be retried in Türkiye even if a foreign judgment has been rendered. However, for offences committed abroad by Turkish citizens under Article 11, Turkish prosecution generally requires that no judgment has been rendered abroad. Article 16 further provides that periods spent abroad in custody, detention or imprisonment for the same offence shall be deducted from the sentence imposed in Türkiye.

This means that foreign proceedings must always be carefully reviewed. The content of the foreign case file, the finality of the decision, the time already served abroad and the nature of the offence may directly affect the Turkish criminal process.

7. Can a Dual Citizen Be Extradited?

Extradition is one of the most sensitive issues in dual citizenship cases. In Türkiye, extradition is mainly governed by Law No. 6706 on International Judicial Cooperation in Criminal Matters, applicable treaties, international custom and reciprocity. The Turkish Ministry of Justice also refers to the constitutional principle that a citizen cannot be extradited to a foreign country for a criminal offence.

Law No. 6706 provides that an extradition request shall not be accepted if the requested person is a Turkish citizen, except for obligations arising from membership in the International Criminal Court system.

Accordingly, if a dual citizen also holds Turkish nationality, that Turkish nationality may create strong protection against extradition from Türkiye. However, this does not mean that the person cannot be prosecuted. If the legal conditions are satisfied, Türkiye may conduct its own criminal proceedings.

8. Conclusion

The question “Which law applies to crimes committed by dual citizens?” cannot be answered simply by looking at which passport the person used. In criminal law, the decisive factors are the place of the offence, the nationality of the offender, the nationality of the victim, the type of crime and the jurisdictional interests of the states involved.

If the crime is committed in Türkiye, Turkish criminal law applies. If the crime is committed abroad by a Turkish dual citizen, Article 11 of the Turkish Criminal Code may apply. If the offence is committed against Türkiye, a Turkish citizen or a Turkish legal entity, Article 12 may become relevant. For certain serious crimes such as drug trafficking, bribery, torture, counterfeiting or crimes against state security, Article 13 may allow Turkish law to apply regardless of nationality.

Dual citizenship does not eliminate criminal liability. On the contrary, it may cause overlapping jurisdiction between different states. Therefore, every case involving dual citizens must be assessed together with Turkish criminal law, international judicial cooperation rules, extradition law, foreign court decisions, sentence deduction rules and procedural requirements.