Judicial Cooperation in Criminal Matters: Mutual Recognition, Extradition, and the European Arrest Warrant

Judicial Cooperation in Criminal Matters: Mutual Recognition, Extradition, and the European Arrest Warrant

Introduction

Judicial cooperation in criminal matters is one of the most significant and sensitive dimensions of the European Union’s Area of Freedom, Security and Justice. It addresses a fundamental challenge of European integration: criminal activity, evidence, suspects, victims, and proceeds of crime can cross national borders, while criminal investigations, prosecutions, and trials remain largely organised within national legal systems.

A person suspected of committing an offence in one Member State may be found in another. Evidence relevant to a prosecution may be held by a bank, telecommunications provider, or public authority in a different country. Criminal proceeds may be transferred through several jurisdictions, while witnesses and victims may live far from the state conducting the investigation. If national authorities cannot cooperate effectively, offenders may exploit territorial boundaries, investigations may become fragmented, and criminal proceedings may be delayed or frustrated.

The European Union has responded by developing a framework of judicial and police cooperation based on mutual recognition, common minimum standards, and specialised legal instruments. Its most recognisable mechanism is the European Arrest Warrant (EAW), which replaced traditional extradition procedures between participating Member States with a system of judicial surrender. Other important instruments govern the freezing and confiscation of criminal assets, the gathering of evidence abroad, the transfer of prisoners, the recognition of judgments, and the protection of procedural rights.

This framework does not establish a single European criminal code, a unified prosecution service for all offences, or a general European criminal court. Member States retain their own criminal laws, courts, prosecutors, police forces, and penal systems. The EU instead creates mechanisms through which national authorities can cooperate, recognise one another’s judicial decisions, and address cross-border criminality within a shared legal framework.

The constitutional foundation is principally found in Articles 82–86 of the Treaty on the Functioning of the European Union (TFEU). These provisions establish the legal basis for judicial cooperation, approximation of selected criminal-law rules, Eurojust, and the possibility of establishing a European Public Prosecutor’s Office.

The central legal questions are therefore distinct but closely connected:

1. Mutual recognition: Under what conditions must a Member State recognise and execute a judicial decision issued by another Member State?
2. Surrender and extradition: How can a person sought for prosecution or the enforcement of a sentence be transferred between Member States?
3. Evidence and investigation: How can authorities obtain, preserve, and exchange evidence located abroad?
4. Criminal assets: How can property connected with criminal activity be frozen, confiscated, and recovered across borders?
5. Procedural rights: What safeguards protect suspects, accused persons, convicted persons, and victims during cross-border cooperation?

The challenge is to reconcile effective enforcement with legality, proportionality, judicial independence, and fundamental rights. Cooperation must be sufficiently efficient to prevent national borders from becoming obstacles to justice, but it must never turn mutual recognition into automatic acceptance of decisions that violate the essential guarantees of a fair criminal process.

1. Constitutional and Legal Foundations of EU Criminal Judicial Cooperation

The Treaty of Lisbon, which entered into force in December 2009, substantially reshaped the constitutional framework for EU action in criminal matters. It brought much of the former third-pillar cooperation within the ordinary EU legal framework and gave the Union clearer legislative powers, while preserving important limits on those powers.

1.1 Article 82 TFEU: Mutual recognition and procedural cooperation

Article 82 TFEU establishes mutual recognition of judgments and judicial decisions as the principal basis of judicial cooperation in criminal matters. It also authorises the adoption of measures designed to facilitate cooperation between judicial or equivalent authorities in relation to criminal proceedings and the enforcement of decisions.

Article 82(2) permits the European Parliament and the Council, acting through the ordinary legislative procedure, to establish minimum rules where necessary to facilitate mutual recognition and police and judicial cooperation in criminal matters having a cross-border dimension.

These minimum rules may concern:

• Mutual admissibility of evidence between Member States.
• The rights of individuals in criminal procedure.
• The rights of victims of crime.
• Other specific aspects of criminal procedure identified by the Council, subject to the Treaty conditions.

The provision does not require every Member State to adopt identical criminal procedures. It allows the Union to establish common minimum safeguards in areas where differences between national systems could undermine cooperation or the protection of individuals.

Article 82 therefore combines two ideas: national procedural autonomy and the need for a common foundation of trust. A judicial authority should be able to rely on decisions from another Member State, but that reliance is more legitimate when minimum procedural guarantees are respected throughout the Union.

1.2 Article 83 TFEU: Approximation of substantive criminal law

Article 83 TFEU provides the legal basis for the approximation of national criminal laws in defined areas.

For particularly serious crime with a cross-border dimension, Article 83(1) identifies areas in which the Union may establish minimum rules concerning the definition of criminal offences and sanctions. These include terrorism, trafficking in human beings, sexual exploitation of women and children, illicit drug trafficking, illicit arms trafficking, money laundering, corruption, counterfeiting of means of payment, computer crime, and organised crime.

The list may be extended by a unanimous Council decision, subject to the Treaty procedure, where developments in crime demonstrate a need for further harmonisation.

Article 83(2) provides a different basis for criminal-law approximation. Where the approximation of national laws and regulations in a particular policy area has been essential to the effective implementation of a Union policy, the EU may establish minimum rules concerning criminal offences and sanctions in that area.

This mechanism is particularly relevant to offences affecting the environment, financial interests, market regulation, and other fields in which the effective operation of EU policies may require criminal-law protection.

The distinction between Article 82 and Article 83 is important. Article 82 primarily concerns judicial cooperation and procedural rules, whereas Article 83 concerns minimum standards relating to criminal offences and penalties.

1.3 Article 84 TFEU: Crime prevention

Article 84 allows the Union to establish measures to promote and support Member States’ action in the field of crime prevention. It expressly excludes harmonisation of national laws and regulations under this provision.

The distinction reflects the limits of EU competence. The Union may support research, cooperation, exchange of good practices, and coordinated prevention policies without using Article 84 as a general authority to unify national criminal legislation.

1.4 Articles 85 and 86 TFEU: Eurojust and the European Public Prosecutor’s Office

Article 85 provides for Eurojust, the EU agency responsible for supporting and strengthening coordination and cooperation between national investigating and prosecuting authorities in relation to serious crime affecting two or more Member States or requiring prosecution on common bases.

Article 86 provides the Treaty basis for the establishment of the European Public Prosecutor’s Office (EPPO). The EPPO is a more integrated institution, empowered to investigate and prosecute offences affecting the financial interests of the Union, subject to its governing legal framework and the participation arrangements of Member States.

These institutions illustrate that EU criminal cooperation has developed beyond simple requests between national authorities. It now includes permanent structures designed to coordinate complex investigations and, in the EPPO’s case, conduct prosecutions within a defined field of EU competence.

The Treaty provisions can be consulted in the official consolidated text of the Treaty on the Functioning of the European Union.

2. The Principle of Mutual Recognition in Criminal Matters

Mutual recognition is the cornerstone of judicial cooperation in criminal matters. It requires Member States, subject to the conditions and safeguards established by EU law, to recognise and give effect to judicial decisions issued by competent authorities in other participating Member States.

The principle was developed to overcome the limitations of traditional international legal assistance. Under older extradition and mutual legal assistance systems, cooperation frequently depended on diplomatic channels, executive discretion, and extensive formal procedures. Requests could take considerable time, and differences between national legal systems sometimes made cooperation unpredictable.

Mutual recognition introduced a different approach. Instead of requiring the requested state to conduct a fresh examination of the entire case, the executing authority generally relies on the decision issued by the judicial authority of the issuing state. The executing authority examines whether the legal conditions for recognition or execution are satisfied and whether a recognised ground for refusal applies.

The principle is based on an assumption of mutual trust: Member States share a commitment to democracy, the rule of law, fundamental rights, and judicial protection. Their judicial systems are therefore expected to provide a sufficient common foundation for cross-border cooperation.

However, mutual recognition does not mean that every foreign judicial decision must be executed regardless of its circumstances. EU legislation contains refusal grounds, procedural guarantees, and proportionality requirements. The Court of Justice of the European Union has also clarified that mutual trust cannot be treated as an irrebuttable presumption where specific evidence indicates a serious risk to fundamental rights.

2.1 Mutual recognition and national sovereignty

Criminal law is traditionally one of the most sensitive expressions of state sovereignty. It defines prohibited conduct, establishes penalties, determines the conditions of criminal responsibility, and regulates the relationship between the state and individuals accused of wrongdoing.

The EU system does not eliminate this national authority. Member States continue to decide which conduct constitutes a criminal offence under their domestic laws, subject to applicable EU requirements. They retain their own prosecutors, courts, police authorities, prisons, and procedural systems.

Mutual recognition nevertheless requires states to accept certain consequences of decisions made elsewhere. A Member State may be required to surrender a person to another Member State even where its own authorities would have approached the underlying case differently, provided the applicable legal conditions are met.

This creates a distinctive form of integration. National criminal justice systems remain separate, but they operate within a framework that makes their decisions capable of producing effects across borders.

2.2 Mutual recognition is not complete harmonisation

It is important to distinguish mutual recognition from harmonisation.

Harmonisation seeks to bring national laws closer together by establishing common rules or minimum standards. Mutual recognition allows national authorities to rely on decisions made under different national legal systems.

For example, an EU instrument may require a Member State to execute a judicial decision issued elsewhere without requiring both states to have identical procedural rules. Nevertheless, the executing state must respect the safeguards established by the relevant instrument and the fundamental rights protected by EU law.

The relationship between the two principles is complementary. A degree of harmonisation, particularly in procedural rights, strengthens the confidence needed for mutual recognition to function legitimately.

3. The European Arrest Warrant: The Central Mechanism of Judicial Surrender

The European Arrest Warrant is the most prominent instrument of EU judicial cooperation in criminal matters.

It was established by Council Framework Decision 2002/584/JHA of 13 June 2002 on the European arrest warrant and the surrender procedures between Member States. It became operational on 1 January 2004 and replaced the traditional extradition arrangements between participating EU Member States.

The EAW is a judicial decision issued by one Member State requesting another Member State to arrest and surrender a person for either:

• Criminal prosecution in the issuing state; or
• Execution of a custodial sentence or detention order already imposed.

The mechanism is based on direct cooperation between judicial authorities rather than the conventional diplomatic extradition model.

The European e-Justice Portal describes the EAW as a simplified surrender procedure that applies throughout the EU, replacing the lengthy extradition procedures previously used between Member States. European e-Justice Portal+1

3.1 Why the European Arrest Warrant was introduced

Before the EAW, extradition between EU Member States was governed by a combination of international conventions, national legislation, and bilateral arrangements. These systems frequently involved executive authorities and formal diplomatic procedures.

The traditional model could be slow and complicated. It also allowed significant differences between national approaches to affect the outcome of requests.

The EAW was introduced to make surrender more judicial, direct, and efficient. It replaced the conventional political extradition process with a system in which competent judicial authorities communicate directly and apply common EU rules.

This change reflects a broader constitutional development. The transfer of a person between Member States is treated primarily as a matter of judicial cooperation rather than a diplomatic decision concerning relations between sovereign states.

The Framework Decision nevertheless leaves important matters to national law. Member States designate the competent issuing and executing judicial authorities, regulate aspects of the procedure, and implement the Framework Decision within their domestic legal systems.

3.2 Issuing and executing judicial authorities

The EAW involves two principal authorities.

The issuing judicial authority is the competent authority in the Member State requesting the surrender. It issues the warrant on the basis of a national arrest warrant or another enforceable judicial decision having the required effect.

The executing judicial authority is the competent authority in the Member State where the requested person is located. It receives the warrant, determines whether the legal conditions for execution are satisfied, and decides whether surrender should take place.

The Framework Decision requires the participating states to designate their competent authorities. The precise institutional arrangements differ between national systems.

The concept of a judicial authority has also been examined by the Court of Justice. In its case law, the Court has distinguished independent judicial authorities from public prosecutors or other bodies that may be subject to directions or instructions from the executive in relation to issuing an EAW.

This is important because the EAW directly affects individual liberty. A decision initiating surrender must therefore satisfy the standards of judicial independence and effective judicial protection required by EU law.

3.3 The two principal purposes of an EAW

An EAW may be issued for prosecution or for the enforcement of a sentence.

First, an EAW may seek a person for prosecution. In this situation, the person is wanted to face criminal proceedings in the issuing Member State. The warrant is not a finding of guilt. The requested person remains entitled to the presumption of innocence and to the procedural guarantees applicable to criminal proceedings.

Secondly, an EAW may seek a person to serve a sentence or detention order. Here, a court in the issuing state has already imposed a custodial sentence or detention order, and the requested person is sought so that the decision can be enforced.

The distinction matters because the Framework Decision establishes different minimum thresholds for issuing warrants depending on their purpose.

3.4 Thresholds for issuing a European Arrest Warrant

Under Article 2 of the Framework Decision, an EAW may be issued for prosecution where the offence is punishable under the law of the issuing Member State by a custodial sentence or detention order with a maximum duration of at least 12 months.

For the execution of an already imposed custodial sentence or detention order, the remaining sentence must be at least four months.

These thresholds are intended to prevent the EAW from becoming a disproportionate mechanism for pursuing very minor offences or negligible custodial penalties.

The thresholds do not mean that every offence punishable by a maximum sentence of 12 months must result in an EAW. The issuing authority must still consider whether surrender is necessary and proportionate in the circumstances. The seriousness of the alleged conduct, the likely sentence, the availability of less intrusive measures, and the practical purpose of the warrant are relevant considerations.

3.5 The 32 categories of offences and the abolition of double criminality

One of the most important innovations of the EAW is the partial abolition of the double-criminality requirement.

Traditionally, extradition generally required the conduct for which surrender was sought to constitute a criminal offence in both the requesting and requested states. This was known as the principle of double criminality.

Article 2(2) of the Framework Decision identifies 32 categories of offences for which verification of double criminality is not required, provided the offence is punishable in the issuing Member State by a custodial sentence or detention order with a maximum duration of at least three years.

The categories include:

• Participation in a criminal organisation.
• Terrorism.
• Trafficking in human beings.
• Sexual exploitation of children and child pornography.
• Illicit trafficking in narcotic drugs and psychotropic substances.
• Illicit trafficking in weapons, munitions, and explosives.
• Corruption.
• Fraud, including fraud affecting the financial interests of the European Communities.
• Money laundering.
• Counterfeiting currency.
• Computer-related crime.
• Environmental crime.
• Facilitation of unauthorised entry and residence.
• Murder and grievous bodily injury.
• Illicit trade in human organs and tissue.
• Kidnapping, illegal restraint, and hostage-taking.
• Racism and xenophobia.
• Organised or armed robbery.
• Illicit trafficking in cultural goods.
• Swindling.
• Racketeering and extortion.
• Counterfeiting and piracy of products.
• Forgery of administrative documents and trafficking in them.
• Forgery of means of payment.
• Illicit trafficking in hormonal substances and other growth promoters.
• Illicit trafficking in nuclear or radioactive materials.
• Trafficking in stolen vehicles.
• Rape.
• Arson.
• Crimes within the jurisdiction of the International Criminal Court.
• Unlawful seizure of aircraft or ships.
• Sabotage.

For these categories, the executing state does not normally examine whether the conduct also constitutes an offence under its own criminal law.

For offences outside the list, the executing authority may apply the double-criminality requirement, subject to the conditions and exceptions in the Framework Decision.

The abolition of double criminality for specified categories is one of the clearest examples of mutual recognition in practice. It does not mean that the executing state agrees with the criminal policy of the issuing state in every respect. Rather, it accepts the common legislative decision that the listed categories are sufficiently serious to justify surrender without a separate comparison of offence definitions.

The full list and applicable conditions appear in Article 2 of Framework Decision 2002/584/JHA.

3.6 The form and content of the warrant

An EAW must contain the information required by Article 8 of the Framework Decision. This includes the identity and nationality of the requested person, the name and address of the issuing judicial authority, the legal basis for the warrant, details of the enforceable judicial decision, the nature and legal classification of the offence, and a description of the circumstances in which it was committed.

The warrant must also indicate the penalty imposed or the maximum penalty available under the law of the issuing state.

The information must be sufficiently precise to enable the executing authority to identify the person, understand the legal basis of the request, and assess whether the conditions for surrender are met.

The EAW is transmitted through the channels established by the Framework Decision. The Schengen Information System (SIS) can be used to circulate alerts concerning persons wanted for arrest for surrender purposes. The alert enables authorities in another Member State to identify and provisionally arrest a person sought under an EAW.

The SIS alert is not itself a substitute for the legal requirements of the warrant. It is an operational mechanism supporting the identification and location of the requested person.

3.7 Arrest and judicial examination in the executing state

When a requested person is located in another Member State, the competent authorities may arrest that person in accordance with the applicable national procedure and the EAW framework.

The person must be informed of the warrant and the possibility of consenting to surrender. They must also be informed of their procedural rights, including access to a lawyer and, where necessary, interpretation and translation.

The executing judicial authority examines the warrant and determines whether surrender should be authorised. It does not conduct a full trial of the alleged offence and does not ordinarily reassess the evidence supporting the prosecution.

This limitation is essential to the system. The executing authority is not acting as an appellate court reviewing the issuing state’s case. Its task is to determine whether the legal conditions for surrender are satisfied and whether any applicable ground for refusal or postponement exists.

3.8 Consent to surrender

A requested person may consent to surrender. Consent must be given voluntarily and with full awareness of its consequences, in accordance with the safeguards laid down by the Framework Decision and national implementing law.

Where consent is validly given, the executing judicial authority should take its decision on surrender within ten days after consent has been given.

The person may also waive the application of the speciality rule, which otherwise restricts the ability of the issuing state to prosecute or detain the surrendered person for certain offences committed before surrender other than the offence for which the person was surrendered.

Consent can therefore accelerate the procedure, but it must not be treated as a purely administrative signature. The requested person must understand the legal consequences of agreeing to surrender.

3.9 Time limits for surrender

The Framework Decision establishes strict time limits intended to prevent surrender proceedings from becoming unnecessarily prolonged.

Where the requested person consents to surrender, the final decision on execution of the EAW should generally be taken within ten days after consent.

Where the person does not consent, the final decision should generally be taken within 60 days of arrest. In specific cases where the warrant cannot be executed within that period, the executing judicial authority may extend the deadline by a further 30 days, provided that the issuing authority is informed and reasons are given.

Once the final decision to execute the warrant has been taken, surrender should normally take place within ten days. The Framework Decision provides for postponement in certain circumstances, including serious humanitarian reasons, and establishes arrangements for temporary surrender where appropriate.

These deadlines distinguish the EAW from traditional extradition procedures, which could involve extensive administrative and diplomatic stages. They are designed to make surrender predictable without removing the need for judicial examination.

3.10 The speciality rule

The speciality rule protects a person who has been surrendered under an EAW from being prosecuted, sentenced, or deprived of liberty in the issuing state for certain offences committed before surrender other than the offence for which surrender was granted.

The rule prevents the issuing state from using a warrant for one offence as a general means of obtaining a person for unrelated proceedings without respecting the executing state’s decision.

There are exceptions. These include circumstances in which the person has had an opportunity to leave the issuing state but has not done so within the prescribed period, has returned voluntarily, or has consented to prosecution for additional offences. The Framework Decision also permits certain exceptions subject to the executing authority’s consent.

The speciality principle is an important procedural protection because surrender is granted for a defined legal purpose, not as an unrestricted transfer of the person to the issuing state’s jurisdiction.

4. Grounds for Refusing Execution of a European Arrest Warrant

Although the EAW is based on mutual recognition, the executing judicial authority does not have an unconditional obligation to surrender every requested person. Articles 3, 4, and 4a of Framework Decision 2002/584/JHA establish mandatory and optional grounds for non-execution.

These grounds are deliberately limited. They preserve the effectiveness of the surrender system while ensuring that serious legal obstacles and fundamental rights concerns can be considered.

4.1 Mandatory grounds for refusal

Article 3 identifies circumstances in which the executing judicial authority must refuse to execute the warrant.

The first concerns amnesty. If the offence is covered by an amnesty in the executing Member State, and that state had jurisdiction to prosecute the offence under its own criminal law, surrender must be refused.

The second concerns ne bis in idem. This principle prevents a person from being prosecuted or punished twice for the same acts where the relevant legal conditions are satisfied. If the executing authority is informed that the requested person has already been finally judged by a Member State for the same acts, and the sentence has been served, is being served, or can no longer be enforced under the law of that state, the warrant must not be executed.

The third concerns age. A warrant must not be executed where the requested person cannot, because of their age, be held criminally responsible for the acts on which the warrant is based under the law of the executing Member State.

These mandatory grounds protect fundamental principles of criminal justice. They recognise that mutual recognition cannot require a state to disregard its own legally established protections in circumstances expressly identified by EU law.

4.2 Optional grounds for refusal

Article 4 identifies circumstances in which the executing judicial authority may refuse execution.

These include situations in which the conduct does not constitute an offence under the law of the executing state, subject to the exceptions applicable to the 32 listed categories of offences. Other grounds concern ongoing or discontinued proceedings in the executing state, limitation periods, final judgments in certain third-country proceedings, and the territorial circumstances in which the offence was committed.

A further important ground concerns the requested person who is a national or resident of the executing Member State, or who is staying there, where the executing state undertakes to enforce the sentence in accordance with its domestic law.

The precise application of these grounds depends on the relevant provision and the national law implementing the Framework Decision. An executing authority must not treat an optional ground as an unrestricted political discretion to refuse cooperation.

4.3 Judgments delivered in absentia

Article 4a addresses the execution of an EAW where the requested person was convicted following proceedings at which they did not appear in person.

The provision reflects a difficult balance. A person should not be able to avoid surrender merely because a trial took place in their absence, but neither should a Member State be required to enforce a conviction where the defendant was denied a meaningful opportunity to participate in the proceedings.

Execution may be refused in specified circumstances, particularly where the person was not properly informed of the trial or did not have an adequate opportunity to arrange their defence. The provision also recognises circumstances in which the person was represented by a lawyer instructed by them, or was informed of the right to a retrial or appeal that allows the merits of the case to be re-examined.

The objective is to ensure that convictions in absentia satisfy minimum standards of defence rights and procedural fairness.

4.4 Guarantees required from the issuing state

Article 5 allows execution to be made subject to particular guarantees in certain cases.

One example concerns a sentence imposed for an offence punishable by life imprisonment or a life sentence. The executing state may require sufficient guarantees that the issuing state’s legal system provides for a review of the penalty or a measure of clemency that may prevent the sentence from being executed.

Another guarantee concerns nationals or residents of the executing state who are surrendered for prosecution. Under the conditions of the Framework Decision, the executing authority may require that the person, after being heard, be returned to the executing state to serve any custodial sentence imposed in the issuing state.

These provisions demonstrate that surrender is not necessarily an irreversible transfer of every aspect of the person’s legal position. The Framework Decision permits specified guarantees to protect the interests of the requested person and the legal order of the executing state.

5. Fundamental Rights and the Limits of Mutual Trust

The most important legal limitation on mutual recognition is the obligation to respect fundamental rights.

Article 1(3) of Framework Decision 2002/584/JHA expressly states that the EAW framework does not modify the obligation to respect fundamental rights and fundamental legal principles as enshrined in Article 6 of the Treaty on European Union.

The Charter of Fundamental Rights is particularly relevant. The following provisions frequently arise in surrender proceedings:

• Article 4 prohibits torture and inhuman or degrading treatment or punishment.
• Article 6 protects the right to liberty and security.
• Article 47 guarantees an effective remedy and a fair trial.
• Article 48 protects the presumption of innocence and the rights of the defence.
• Article 49 establishes principles concerning legality and proportionality of criminal offences and penalties.
• Article 50 protects the right not to be tried or punished twice for the same criminal offence.

The European Convention on Human Rights also remains an essential source of protection, particularly through Article 3, which prohibits torture and inhuman or degrading treatment, and Article 6, which guarantees the right to a fair trial.

5.1 Aranyosi and Căldăraru: detention conditions

One of the leading judgments is Aranyosi and Căldăraru v Generalstaatsanwaltschaft Bremen (Joined Cases C-404/15 and C-659/15 PPU, 5 April 2016).

The case concerned EAWs issued by Hungary and Romania. The executing German court received information indicating that detention conditions in the issuing states could expose the requested persons to a real risk of inhuman or degrading treatment.

The Court of Justice held that mutual trust does not require surrender where there is a real risk of treatment contrary to Article 4 of the Charter.

However, the Court did not establish a general power to refuse EAWs whenever concerns about prison conditions are raised. It developed a structured assessment.

First, the executing judicial authority must determine whether there is objective, reliable, specific, and properly updated evidence indicating systemic or generalised deficiencies in detention conditions, or deficiencies affecting certain groups of people or particular detention facilities.

Secondly, it must assess whether substantial grounds exist for believing that the specific person concerned would face a real risk of inhuman or degrading treatment if surrendered.

The executing authority must seek additional information from the issuing judicial authority where necessary. If the risk cannot be excluded within a reasonable period, the executing authority must decide whether the surrender procedure should be brought to an end.

The judgment established that fundamental rights are not suspended by mutual recognition. At the same time, it preserved the principle that concerns must be assessed individually rather than used as a general justification for refusing cooperation.

The judgment is available through the official Court of Justice case record.

5.2 Judicial independence: LM

Another major judgment is Minister for Justice and Equality v LM (Case C-216/18 PPU, 25 July 2018), often referred to as the LM or Celmer judgment.

The case concerned concerns about the independence of the judiciary in the issuing Member State and the possible effect on the requested person’s right to a fair trial.

The Court of Justice accepted that serious deficiencies affecting judicial independence could, in principle, justify further examination of whether surrender would expose a person to a real risk of violation of the essence of the right to a fair trial under Article 47 of the Charter.

It nevertheless required an individual assessment. General evidence concerning institutional problems is relevant, but the executing judicial authority must also examine whether the particular person would face a genuine risk of a breach of the right to an independent tribunal established by law.

The authority may need to consider the nature of the offence, the factual context, the personal circumstances of the requested person, and any relevant information concerning the courts likely to hear the case.

This approach reinforces the distinction between generalised concerns and a specific, individual risk. It also demonstrates that mutual trust depends on the actual functioning of judicial institutions rather than a purely formal assumption that all national systems are necessarily equivalent in every respect.

5.3 The importance of individual assessment

The case law on detention conditions and judicial independence reveals a fundamental constitutional principle: mutual recognition cannot override the Charter.

Nevertheless, the executing authority must apply a rigorous legal test. It cannot substitute its own general assessment of another Member State’s legal system for the specific inquiry required by EU law.

This balance is important for two reasons. First, it protects individuals against serious fundamental rights violations. Secondly, it prevents political disagreement or broad institutional criticism from becoming a routine obstacle to judicial cooperation.

The result is a framework in which mutual trust remains the general rule, but the executing judicial authority retains a carefully defined responsibility to examine exceptional risks.

6. Extradition and the European Arrest Warrant: Understanding the Difference

The terms extradition and surrender are sometimes used interchangeably in everyday language, but they have different legal meanings within the EU framework.

Traditional extradition is a process through which one state requests another state to transfer a person for prosecution or punishment. It is generally governed by international treaties, domestic extradition legislation, and, in some systems, executive or diplomatic procedures.

The EAW is different. It is a judicial surrender mechanism operating between participating Member States under a common EU instrument.

Traditional extradition	European Arrest Warrant
Primarily based on international treaties and national extradition law	Based on Framework Decision 2002/584/JHA
May involve diplomatic or executive authorities	Direct cooperation between judicial authorities
Often requires extensive formal documentation	Uses a standardised warrant form
Double criminality is generally important	Not required for the 32 listed categories if the applicable penalty threshold is met
May involve broader political or national-law grounds for refusal	Refusal is governed by specific EU grounds and applicable safeguards
Procedures may be lengthy	Strict decision and surrender deadlines apply

The EAW is therefore not simply an accelerated form of traditional extradition. It represents a change in the legal relationship between Member States: surrender is based on judicial recognition rather than the conventional extradition relationship between sovereign states.

6.1 Extradition to and from third countries

The EAW operates within the EU framework. Where a person is sought by or located in a non-EU country, different legal rules may apply.

Extradition between a Member State and a third country may be governed by the European Convention on Extradition of 1957, bilateral extradition treaties, other multilateral conventions, and national legislation.

The position of the United Kingdom is an important example. Following Brexit, the UK no longer participates in the EAW system as a Member State. Surrender between the UK and EU Member States is principally governed by the extradition arrangements in the EU–UK Trade and Cooperation Agreement, together with the relevant national implementing law and applicable safeguards.

The Trade and Cooperation Agreement retains a surrender mechanism inspired by the EAW, but it is not legally identical to the intra-EU system. It includes specific grounds for refusal and arrangements concerning nationality, political offences, and fundamental rights.

Relations with Norway and Iceland are also governed by a separate surrender agreement between those countries and the EU. This agreement draws on the principles of the EAW but operates as an international arrangement rather than as an application of the Framework Decision itself.

The applicable legal basis must therefore be identified before a surrender request is assessed. The fact that a country is geographically European, or has close institutional relations with the EU, does not automatically make the EAW applicable.

7. The European Investigation Order: Obtaining Evidence Across Borders

The surrender of suspects is only one part of cross-border criminal cooperation. Investigations also depend on the ability to obtain evidence located in another Member State.

A criminal investigation may require witness testimony, banking records, telephone data, surveillance material, searches of premises, expert examinations, or the preservation of digital information. If the evidence is located abroad, the investigating authority must use an appropriate mechanism to obtain it lawfully.

The principal EU instrument is Directive 2014/41/EU regarding the European Investigation Order in criminal matters.

The European Investigation Order (EIO) is a judicial decision issued or validated by a judicial authority in one Member State, requesting another Member State to carry out one or more specific investigative measures to obtain evidence.

The EIO is based on mutual recognition. The executing state is, in principle, required to recognise and execute the order in accordance with the Directive, subject to the prescribed grounds for refusal or postponement.

The instrument creates a comprehensive framework for cross-border evidence gathering and replaces several earlier, more fragmented mechanisms for the participating states. It has applied since 22 May 2017. Denmark and Ireland are not bound by the Directive.

The European Commission explains that the EIO may be used for a wide range of investigative measures, including hearing witnesses, telephone interception, covert investigations, and obtaining information about banking operations. European Commission+2

7.1 Scope and issuing authorities

An EIO may be issued in criminal proceedings by a judicial authority or another competent authority, provided the decision is validated by a judicial authority where the Directive requires validation.

It may be used in proceedings initiated by judicial authorities concerning criminal offences, or in certain proceedings conducted by administrative authorities where their decisions may give rise to proceedings before a court having jurisdiction in criminal matters.

The order must identify the investigative measure requested, the purpose of the investigation, and the relevant information concerning the offence and the person concerned.

Importantly, the EIO is not restricted to evidence that must be created through a new investigative measure. It may also be issued to obtain evidence that is already in the possession of the executing state’s competent authorities.

7.2 Recognition and execution

The executing authority must generally recognise the EIO without requiring additional formalities and ensure its execution in the same way, as far as possible, as if the investigative measure had been ordered by an authority of the executing state.

The executing authority should observe the formalities and procedures expressly indicated by the issuing authority, provided that they are not contrary to fundamental principles of the law of the executing state.

This allows evidence to be gathered in a manner that can be used effectively in the proceedings for which it is required, while respecting the legal framework of the state carrying out the measure.

The Directive establishes deadlines for recognition and execution. As a general rule, a decision on recognition or execution should be taken as soon as possible and no later than 30 days after receipt of the EIO. The investigative measure should normally be carried out within 90 days of that decision, subject to the conditions and exceptions in the Directive.

7.3 Grounds for refusal

Recognition and execution are not unconditional. The Directive establishes grounds on which an executing state may refuse an EIO.

These include circumstances in which execution would be incompatible with the principle of ne bis in idem, would conflict with certain immunities or privileges, or would harm essential national security interests. Refusal may also arise where the conduct does not constitute an offence under the law of the executing state, subject to exceptions for specified categories of serious offences.

The executing authority must also consider proportionality. An investigative measure should not be authorised merely because it is technically possible. Its necessity, suitability, and impact on the rights of the persons affected must be assessed.

7.4 Defence rights and the European Investigation Order

An important feature of the EIO framework is that it is not exclusively an instrument for prosecutors or investigating authorities.

Under Article 1 of the Directive, an EIO may also be requested by a suspected or accused person, or by their lawyer, within the framework of the applicable rights of the defence and national criminal procedure.

This matters because cross-border cooperation should not be understood solely as a means of increasing the powers of the state. It can also enable the defence to obtain evidence located abroad, identify witnesses, and establish facts relevant to the accused person’s case.

The EIO therefore contributes to a more balanced system of transnational criminal procedure.

7.5 The modernisation of evidence cooperation

The European Commission adopted a proposal on 23 June 2026 to recast Directive 2014/41/EU. The proposed reform seeks to modernise evidence-gathering cooperation and establish clearer common rules for remote participation by suspects, accused persons, and victims in criminal proceedings through videoconferencing from another Member State.

As a legislative proposal, it must be distinguished from the rules already in force. Its eventual effect depends on the EU legislative process and the final text adopted by the co-legislators.

This development illustrates the growing importance of digital evidence and remote judicial participation in cross-border criminal cases. European Commission+1

8. Electronic Evidence and the European E-Evidence Package

Modern criminal investigations increasingly depend on digital information. Emails, messaging records, subscriber details, internet protocol addresses, cloud-stored files, and other electronic data may be essential to identifying suspects and reconstructing criminal conduct.

The difficulty is that electronic information is often held by a service provider established in a different country from the one investigating the offence. Traditional mutual legal assistance procedures can be too slow where data are vulnerable to deletion or alteration.

The EU has therefore adopted a dedicated e-evidence framework consisting of:

• Regulation (EU) 2023/1543 on European Production Orders and European Preservation Orders for electronic evidence in criminal proceedings and for the execution of custodial sentences.
• Directive (EU) 2023/1544 establishing harmonised rules on the designation of designated establishments and the appointment of legal representatives for gathering electronic evidence.

The Regulation applies from 18 August 2026. It is therefore an operational part of the EU criminal justice framework as at November 2026. EUR-Lex+2

8.1 European Production Orders

A European Production Order allows a competent authority in one Member State to require a service provider offering services in the Union to produce specified electronic evidence.

The order is directed at obtaining data that may be relevant to a criminal investigation or prosecution. Depending on the type of data and the circumstances, the order may be subject to different issuing and validation requirements.

The framework distinguishes between subscriber data, access data, transactional data, and content data. This distinction matters because different categories of information have different levels of sensitivity and implications for privacy.

The Regulation establishes safeguards concerning the competence of issuing authorities, the legal conditions for orders, the rights of service providers, and remedies available to affected persons.

8.2 European Preservation Orders

A European Preservation Order requires a service provider to preserve specified electronic evidence so that it is not deleted or altered while the authorities arrange for its lawful production.

Preservation does not automatically mean disclosure. It secures the availability of data for a subsequent lawful request or order.

This distinction is particularly important in investigations involving organised crime, cybercrime, terrorism, and online financial fraud, where electronic information may be held in several jurisdictions and can be lost quickly.

8.3 Service providers and legal representatives

Directive (EU) 2023/1544 requires service providers offering services in the EU to designate establishments or appoint legal representatives in the Union for the purposes of receiving and complying with orders for electronic evidence.

The aim is to ensure that competent authorities can identify a legally responsible point of contact, even where the provider is established outside the EU.

The framework also seeks to balance the effectiveness of criminal investigations with data protection, privacy, confidentiality, and the rights of individuals affected by the requested information.

The e-Evidence Regulation is available through EUR-Lex, while the corresponding Directive is available at Directive (EU) 2023/1544.

9. Eurojust: Coordination of Cross-Border Criminal Investigations

Eurojust is the European Union Agency for Criminal Justice Cooperation. It supports and strengthens coordination and cooperation between national authorities responsible for investigating and prosecuting serious crime involving two or more Member States or requiring prosecution on common bases.

It was established to address the practical difficulties arising when several national authorities investigate related criminal conduct.

A complex criminal network may operate through several countries, with different groups of suspects, victims, financial transactions, and evidence located in different jurisdictions. Without coordination, national investigations may overlap, compete, or fail to share essential information.

Eurojust provides a platform for judicial authorities to coordinate their work.

9.1 Legal foundation and institutional role

Article 85 TFEU provides the Treaty basis for Eurojust. Its current legal framework is principally Regulation (EU) 2018/1727.

Eurojust is not a general European criminal court and does not replace national prosecutors. Its role is to facilitate cooperation, coordinate investigations and prosecutions, support the resolution of jurisdictional conflicts, and assist competent authorities in dealing with cross-border procedural difficulties.

Its work may involve:

• Coordinating parallel investigations and prosecutions.
• Facilitating the exchange of information between national authorities.
• Supporting the execution of EAWs and EIOs.
• Helping authorities establish joint investigation teams.
• Assisting with conflicts of jurisdiction.
• Facilitating the freezing and confiscation of criminal assets.
• Supporting cooperation with third countries and international judicial networks.

Eurojust may convene coordination meetings involving prosecutors, judges, and other competent national authorities. These meetings help participants agree on investigative priorities, sequencing of procedural steps, and the most appropriate jurisdiction for prosecution.

9.2 Joint Investigation Teams

A Joint Investigation Team (JIT) is an arrangement established between competent authorities of two or more states for a specific criminal investigation.

Rather than relying exclusively on separate requests for assistance, the participating authorities work together within a common investigative framework.

A JIT can facilitate the exchange of information, coordinated investigative measures, and the participation of officers from different jurisdictions in a shared investigation, subject to the applicable legal arrangements.

Joint investigation teams are particularly useful in cases involving organised criminal groups, trafficking networks, terrorism, cybercrime, and complex financial offences.

Eurojust can provide legal, practical, and logistical support for establishing and operating JITs. It may also assist with funding in accordance with its rules.

9.3 Eurojust and conflicts of jurisdiction

Cross-border criminal conduct may give rise to legitimate jurisdictional claims by several Member States.

For example, a criminal organisation may be based in one country, carry out operations in a second, transfer proceeds through a third, and cause harm in several others. Each state may have grounds to investigate or prosecute.

The existence of multiple possible jurisdictions can produce duplicated proceedings, conflicting investigative decisions, and uncertainty for defendants and victims.

Eurojust helps national authorities assess which jurisdiction is best placed to prosecute. Relevant considerations may include the location of the principal criminal conduct, the residence of suspects and victims, the availability of evidence, the interests of justice, and the possibility of conducting a comprehensive prosecution.

Its role is principally coordinative. Decisions concerning the exercise of national criminal jurisdiction remain governed by the applicable legal rules and the powers of national authorities.

The official Eurojust website provides information about its structure, casework, and judicial cooperation instruments. European Commission+2

10. The European Public Prosecutor’s Office

The European Public Prosecutor’s Office (EPPO) represents a deeper form of integration in EU criminal justice.

Unlike Eurojust, which coordinates national investigations and prosecutions, the EPPO is an independent prosecution office with authority to investigate and prosecute certain criminal offences affecting the financial interests of the Union.

Its legal basis is Article 86 TFEU and its institutional framework is established by Regulation (EU) 2017/1939.

The EPPO began operating on 1 June 2021. As of November 2026, 25 Member States participate, including Bulgaria. Denmark and Ireland do not participate, while the other non-participating Member State is outside the enhanced-cooperation arrangement.

10.1 Material competence

The EPPO’s central responsibility is to investigate, prosecute, and bring to judgment offences affecting the financial interests of the EU.

These offences include serious fraud involving EU funds, corruption affecting the Union budget, money laundering connected with offences affecting the Union’s financial interests, and certain serious cross-border VAT fraud.

The substantive offences are defined principally through Directive (EU) 2017/1371, commonly known as the PIF Directive, as implemented in national law.

The EPPO also has competence in relation to certain offences concerning participation in a criminal organisation where the criminal activity of that organisation is focused on committing offences within its material competence.

The VAT fraud threshold is particularly relevant. For the cross-border VAT fraud category identified in Article 22(1) of Regulation 2017/1939, the EPPO’s competence applies where the intentional conduct involves the territory of at least two Member States and causes total damage of at least €10 million.

The EPPO does not have general jurisdiction over every form of fraud, corruption, or organised crime. Its competence is limited to the offences and conditions established by EU law.

10.2 Structure and operation

The EPPO is organised around a central office and decentralised European Delegated Prosecutors operating in participating Member States.

The central level includes the European Chief Prosecutor, the College of European Prosecutors, and permanent chambers responsible for supervising and directing cases.

European Delegated Prosecutors conduct investigations and prosecutions in the Member States under the Regulation, applying national law where required and operating within the EPPO’s institutional framework.

This structure combines European-level coordination with the practical involvement of prosecutors familiar with national criminal procedure and court systems.

10.3 Relationship with national authorities and Eurojust

The EPPO works with national police, customs, tax, and judicial authorities. National authorities are required to report relevant criminal conduct affecting the Union’s financial interests to the EPPO in accordance with the Regulation.

Where the EPPO exercises its competence, it may conduct investigations and bring cases before national courts. It is therefore different from Eurojust, which does not itself conduct criminal prosecutions.

The two bodies may nevertheless cooperate where their respective mandates overlap or where a case involves both offences within EPPO competence and other serious cross-border crimes.

The EPPO’s institutional framework is established by Regulation (EU) 2017/1939. The Commission’s official EPPO overview explains its mission and institutional role. EUR-Lex+3

11. Recognition of Criminal Judgments and the Transfer of Prisoners

Mutual recognition extends beyond arrest and investigation. EU law also provides mechanisms for recognising criminal judgments and facilitating the enforcement of sentences in another Member State.

These instruments address a practical problem: a person convicted in one country may have strong social, family, or rehabilitation connections with another. Serving a sentence in a state where the person has established residence or maintains meaningful ties may facilitate reintegration and reduce the difficulties associated with imprisonment far from home.

11.1 Framework Decision 2008/909/JHA

Council Framework Decision 2008/909/JHA applies the principle of mutual recognition to judgments imposing custodial sentences or measures involving deprivation of liberty for the purpose of their enforcement in another Member State.

It allows a Member State to transmit a judgment and certificate to another Member State for recognition and enforcement under the prescribed conditions.

The transfer is not simply a matter of administrative convenience. The Framework Decision seeks to facilitate the social rehabilitation of the sentenced person while protecting the rights of the individual and ensuring that the sentence is effectively enforced.

The executing state generally continues enforcement under its own law, subject to the rules governing adaptation and recognition. It cannot ordinarily increase the nature or duration of the sentence imposed by the issuing state.

11.2 Other mutual recognition instruments

Other Framework Decisions address specific aspects of criminal judgments and supervision:

• Framework Decision 2008/947/JHA concerns the recognition of judgments and probation decisions with a view to supervising probation measures and alternative sanctions.
• Framework Decision 2009/829/JHA establishes the European Supervision Order, allowing certain pre-trial supervision measures to be recognised and monitored in another Member State.
• Framework Decision 2005/214/JHA concerns the application of mutual recognition to financial penalties.

These instruments extend cooperation beyond imprisonment. They recognise that criminal justice decisions may involve community-based sanctions, supervision, financial penalties, and pre-trial measures.

11.3 Transfer of criminal proceedings

A separate development is Regulation (EU) 2024/3011 on the transfer of proceedings in criminal matters.

The Regulation establishes common rules for requests to transfer criminal proceedings from one Member State to another where the proper administration of justice would be better served by conducting the proceedings in the requested state.

It is intended to reduce fragmented or duplicative proceedings and provide greater legal certainty about how such transfers should be requested and assessed.

The Regulation includes safeguards for suspects, accused persons, and victims. These include opportunities to express views on a transfer request, access relevant documents, and seek a legal remedy in the requested state against a decision accepting the transfer.

Importantly, the Regulation is not yet applicable as at November 2026. It applies to requests transmitted from 1 February 2027, with the decentralised IT provisions subject to a separate timetable. EUR-Lex+2

This future framework is significant because the location of proceedings can affect access to evidence, witnesses, legal representation, victims, and the accused person’s practical ability to participate in the case.

12. Freezing and Confiscation of Criminal Assets

Cross-border criminal activity frequently involves the movement of money, property, and other assets between jurisdictions. A criminal investigation may identify proceeds of crime in one Member State even though the investigation and prosecution are taking place in another.

Effective cooperation therefore requires mechanisms to preserve assets before they disappear and to enforce confiscation decisions across borders.

Regulation (EU) 2018/1805 governs the mutual recognition of freezing orders and confiscation orders in criminal matters. It has applied since 19 December 2020.

A freezing order prevents property from being destroyed, transformed, transferred, or disposed of where the purpose is to preserve it for possible confiscation. A confiscation order involves the permanent deprivation of property following the relevant criminal proceedings or other qualifying legal basis.

The Regulation requires Member States to recognise and execute qualifying orders issued by another Member State, subject to the grounds for refusal and safeguards contained in the instrument.

It also provides rights of legal remedy for persons affected by freezing and confiscation measures. The substantive reasons for issuing an order are generally not reconsidered by the executing state, but affected persons may challenge recognition and execution before the competent courts in that state in accordance with the Regulation.

The framework is complemented by Directive 2014/42/EU on the freezing and confiscation of instrumentalities and proceeds of crime in the European Union, as well as Directive (EU) 2024/1260 on asset recovery and confiscation.

The latter Directive strengthens the EU framework for identifying, tracing, freezing, managing, and confiscating criminal assets. It also seeks to improve the institutional capacity of national asset recovery and asset management offices.

The policy objective is not merely to punish offenders. It is also to deprive criminal organisations of the economic resources that enable them to operate, expand, and reinvest unlawful profits.

The relevant instruments are available through Regulation (EU) 2018/1805, Directive 2014/42/EU, and Directive (EU) 2024/1260. EUR-Lex+1

13. Procedural Rights in Cross-Border Criminal Proceedings

The legitimacy of mutual recognition depends on more than efficient cooperation between authorities. It also depends on the protection of individuals whose liberty, property, privacy, and procedural position may be affected by cross-border decisions.

The EU has therefore adopted a series of directives establishing minimum procedural safeguards for suspects and accused persons.

These measures are especially important in EAW proceedings, where a person may be arrested in one country and transferred to another in order to face prosecution or serve a sentence.

13.1 The right to interpretation and translation

Directive 2010/64/EU establishes the right to interpretation and translation in criminal proceedings.

A suspect or accused person who does not speak or understand the language of the proceedings must be provided with interpretation where necessary to safeguard fairness. The Directive also establishes rights to translation of essential documents, including documents necessary for exercising the right of defence.

The purpose is to ensure that language does not prevent an individual from understanding the accusation, communicating with counsel, or participating effectively in the proceedings.

13.2 The right to information

Directive 2012/13/EU establishes the right to information in criminal proceedings.

A suspect or accused person must be informed of the criminal act they are suspected or accused of having committed. Where a person is arrested or detained, they must receive information concerning their procedural rights and the reasons for deprivation of liberty.

The Directive also requires access to essential materials in the case file where necessary to challenge effectively the lawfulness of an arrest or detention.

These guarantees are important in EAW proceedings because the requested person must understand the nature of the warrant, the reasons for arrest, and the available legal remedies.

13.3 Access to a lawyer

Directive 2013/48/EU establishes the right of access to a lawyer in criminal proceedings and in European Arrest Warrant proceedings.

A person subject to an EAW has the right to a lawyer in the executing Member State and may also appoint a lawyer in the issuing Member State to assist the lawyer in the executing state.

The Directive also provides safeguards concerning communication with third persons and consular authorities following deprivation of liberty.

The possibility of representation in both states is particularly important because the legal issues arising in surrender proceedings may involve different national procedural systems.

13.4 Presumption of innocence and the right to be present at trial

Directive (EU) 2016/343 strengthens certain aspects of the presumption of innocence and the right to be present at trial in criminal proceedings.

The presumption of innocence requires public authorities to refrain from presenting suspects or accused persons as guilty before their guilt has been established according to law.

The Directive also regulates the burden of proof, the right to remain silent, the privilege against self-incrimination, and safeguards concerning trials in absentia.

These guarantees are directly relevant to the operation of Article 4a of the EAW Framework Decision.

13.5 Procedural safeguards for children

Directive (EU) 2016/800 establishes procedural safeguards for children who are suspects or accused persons in criminal proceedings.

Children require additional protection because of their age, maturity, and particular vulnerability within criminal proceedings.

The Directive addresses assistance by a lawyer, individual assessment, medical examination, limitation of deprivation of liberty, privacy, and the right to be accompanied by a person with parental responsibility or another appropriate adult, subject to its provisions.

The safeguards also matter where a child is subject to an EAW. Cross-border surrender must take account of the special procedural position of children and the requirements of applicable EU and national law.

13.6 Legal aid

Directive (EU) 2016/1919 establishes common rules on legal aid for suspects and accused persons in criminal proceedings and for requested persons in EAW proceedings.

Its purpose is to ensure that individuals who lack sufficient resources can obtain legal assistance where the interests of justice require it, subject to the conditions laid down in the Directive and national implementation.

Legal aid is particularly important in surrender proceedings because the requested person may need to challenge the warrant, raise a ground for refusal, or obtain advice about the consequences of consent.

The Commission’s overview of the rights of suspects and accused persons summarises the main EU safeguards. European Commission+2

14. Victims of Crime and Their Position in Cross-Border Proceedings

Judicial cooperation must also account for the rights and interests of victims.

Directive 2012/29/EU establishes minimum standards on the rights, support, and protection of victims of crime. It applies regardless of whether the victim resides in the Member State where the crime occurred.

Victims may require information about proceedings, access to support services, protection against intimidation or retaliation, and opportunities to participate in criminal proceedings in accordance with national law.

Cross-border cases can make these rights difficult to exercise. A victim may live in one country while the investigation or prosecution takes place in another. They may be required to provide evidence abroad, attend hearings remotely, or communicate with authorities in a language they do not understand.

The EU framework therefore seeks to facilitate access to information, interpretation, protection, and support. The precise procedural rights available to a victim continue to depend on the applicable EU instrument and the national law governing the proceedings.

The interests of victims are also relevant to the proportionality of an EAW. The Commission’s guidance on the warrant identifies victims’ interests among the factors that issuing judicial authorities should consider when deciding whether a warrant is justified.

Victim protection and effective prosecution should not be treated as competing objectives. A fair and effective criminal justice system must take both seriously.

15. Territorial Scope and the Position of Denmark and Ireland

The territorial application of EU criminal justice instruments is not completely uniform.

Denmark and Ireland have special positions under the Treaties in relation to the Area of Freedom, Security and Justice. Their participation in individual measures must therefore be examined separately.

Denmark does not participate in the EU’s criminal judicial cooperation measures in the same manner as other Member States. It has, however, entered into international arrangements that preserve certain forms of cooperation, including arrangements connected with the European Arrest Warrant.

Ireland has exercised its right to opt into a number of EU criminal justice instruments, but it does not participate in all measures. Its position must therefore be checked instrument by instrument.

The European Investigation Order, for example, does not bind Denmark or Ireland. The EAW, by contrast, operates within the EU surrender framework, subject to the applicable participation arrangements.

The EPPO has a different territorial scope. It operates under enhanced cooperation and, as of November 2026, includes 25 Member States. Denmark and Ireland remain outside it.

These distinctions are not merely technical. They affect the legal basis, competent authorities, forms, deadlines, and available remedies in individual cases. A cross-border request should never be assessed solely on the assumption that every EU Member State participates in every criminal justice instrument.

16. Practical Operation: How the Instruments Work Together

The different mechanisms of EU judicial cooperation are most easily understood through a cross-border criminal investigation.

Imagine that an organised criminal group operates in three Member States. Its members are suspected of money laundering, fraudulent transactions, and trafficking in persons. The principal organiser is located in one country, financial transactions are processed through banks in a second, and victims and witnesses are located in a third.

Several legal instruments may become relevant.

First, national police and prosecution authorities investigate the alleged offences under their respective domestic laws. If the investigation requires coordinated action, Eurojust may assist in organising cooperation between the national authorities. A Joint Investigation Team may be established where the conditions are satisfied.

Secondly, if the authorities in one state need to obtain bank records, witness statements, or other evidence from another participating Member State, they may issue a European Investigation Order. Where electronic evidence is held by a service provider, the e-Evidence Regulation may provide the relevant mechanism for obtaining or preserving that information.

Thirdly, if a suspect is located in another Member State, the issuing judicial authority may issue an EAW, provided the legal conditions and proportionality requirements are satisfied. The executing judicial authority then examines the warrant and decides whether surrender should take place.

Fourthly, if the investigation identifies property or funds derived from criminal activity, a freezing order may be issued and transmitted for recognition and execution under Regulation 2018/1805. A confiscation order may follow where the relevant legal conditions are met.

Finally, the authorities must determine which state or states should conduct the prosecution. If the case concerns offences affecting the financial interests of the EU, the EPPO may exercise its competence in participating Member States. In other cases, national prosecutors may coordinate through Eurojust.

This example demonstrates that EU judicial cooperation is not based on a single instrument. It is a network of complementary mechanisms designed to address different stages of criminal proceedings: investigation, evidence gathering, arrest, surrender, prosecution, judgment, and enforcement.

17. Continuing Challenges and Critical Issues

The EU framework has significantly improved the ability of national authorities to address cross-border crime. Nevertheless, its effectiveness depends on conditions that are not always equally present across Member States.

17.1 Differences between national criminal justice systems

Member States retain different criminal codes, procedural rules, evidential standards, sentencing practices, and institutional arrangements.

A conduct classified as a serious offence in one jurisdiction may be defined differently in another. National rules may also differ concerning pre-trial detention, the admissibility of evidence, prosecutorial discretion, and the availability of alternative sanctions.

Mutual recognition does not eliminate these differences. It creates a framework in which decisions can circulate despite them.

This can produce tension, particularly where an executing authority must surrender a person even though the underlying offence, procedure, or potential sentence differs significantly from domestic practice.

17.2 Proportionality and overuse of the European Arrest Warrant

The EAW was designed to facilitate surrender in serious criminal cases. Its use for minor offences or cases in which the likely penalty is limited can impose disproportionate consequences.

A requested person may be arrested far from home, deprived of liberty, required to obtain legal representation in two countries, and separated from family or employment. These consequences may be excessive where a less intrusive measure could achieve the same legitimate objective.

The European Commission has therefore emphasised the importance of proportionality checks before issuing an EAW.

Issuing authorities should consider the seriousness of the offence, the likely sentence, the likelihood that detention will follow surrender, and the interests of victims. The availability of alternative methods of cooperation should also be considered.

The legal thresholds in Article 2 are necessary conditions, not an instruction to issue a warrant in every eligible case.

17.3 Detention conditions and judicial independence

The EAW framework relies on confidence in national judicial systems. Serious deficiencies in detention conditions or judicial independence can undermine that confidence.

The Court of Justice has attempted to preserve mutual recognition while allowing individual protection where a genuine risk to fundamental rights is established.

This approach is legally demanding. Executing authorities must assess the available evidence carefully, request relevant information, and avoid both automatic surrender and unjustified generalised refusals.

The challenge is particularly significant because the effectiveness of the EAW depends on predictable cooperation, while the legitimacy of that cooperation depends on effective fundamental rights protection.

17.4 Electronic evidence and privacy

Digital evidence has become central to criminal investigations, but obtaining it raises questions concerning privacy, confidentiality, data protection, and the rights of third parties.

Electronic information may contain personal communications, sensitive financial details, professional information, and data belonging to individuals who are not suspected of any offence.

The e-Evidence framework must therefore be implemented in a manner consistent with the Charter, the applicable data protection rules, and the requirements of necessity and proportionality.

The speed of electronic production must not become a reason to bypass independent judicial oversight or appropriate safeguards.

17.5 Conflicts of jurisdiction and duplicated proceedings

Where several Member States have jurisdiction over the same criminal conduct, the authorities may disagree about which state should prosecute.

Parallel proceedings can create unnecessary expense, inconsistent decisions, and difficulties for defendants and victims. They may also increase the risk of conflicting judgments.

Eurojust helps resolve these difficulties through coordination, while the new Regulation on the transfer of proceedings will establish a more structured framework from February 2027.

Nevertheless, decisions about jurisdiction must continue to respect national law, the rights of the accused, and the interests of victims.

17.6 Unequal institutional capacity

The effectiveness of judicial cooperation also depends on resources. National authorities differ in staffing, technical infrastructure, specialist expertise, language capacity, and experience with cross-border investigations.

A sophisticated legal framework cannot function properly if requests are delayed, electronic systems are incompatible, or competent authorities lack the resources to process them.

Continued judicial training, institutional cooperation, digitalisation, and practical guidance are therefore essential.

18. Facts: The Principal EU Instruments and Institutions

Instrument or institution	Principal function
Articles 82–86 TFEU	Treaty framework for criminal judicial cooperation
Framework Decision 2002/584/JHA	European Arrest Warrant and surrender
Directive 2014/41/EU	European Investigation Order
Regulation (EU) 2023/1543	Production and preservation of electronic evidence
Directive (EU) 2023/1544	Legal representatives and designated establishments for e-evidence
Regulation (EU) 2018/1727	Eurojust
Regulation (EU) 2017/1939	European Public Prosecutor’s Office
Framework Decision 2008/909/JHA	Recognition and enforcement of custodial sentences
Framework Decision 2008/947/JHA	Recognition of probation measures and alternative sanctions
Framework Decision 2009/829/JHA	European Supervision Order
Framework Decision 2005/214/JHA	Mutual recognition of financial penalties
Regulation (EU) 2018/1805	Mutual recognition of freezing and confiscation orders
Directive (EU) 2024/1260	Asset recovery and confiscation
Regulation (EU) 2024/3011	Transfer of criminal proceedings, applicable from 1 February 2027
Directive 2010/64/EU	Interpretation and translation
Directive 2012/13/EU	Right to information
Directive 2013/48/EU	Access to a lawyer
Directive (EU) 2016/343	Presumption of innocence and right to be present at trial
Directive (EU) 2016/800	Procedural safeguards for children
Directive (EU) 2016/1919	Legal aid in criminal proceedings and EAW proceedings
Directive 2012/29/EU	Rights, support, and protection of victims

19. Key Takeaways

• Articles 82–86 TFEU provide the constitutional foundation for EU judicial cooperation in criminal matters, including mutual recognition, procedural harmonisation, Eurojust, and the EPPO.
• Mutual recognition is the central organising principle. National authorities are expected to recognise and execute qualifying judicial decisions from other participating Member States, subject to EU law and fundamental rights safeguards.
• The European Arrest Warrant replaced traditional extradition procedures between participating Member States with a judicial surrender mechanism based on Framework Decision 2002/584/JHA.
• An EAW may be issued for prosecution or enforcement of a custodial sentence. The general thresholds are a maximum penalty of at least 12 months for prosecution and a remaining sentence of at least four months for enforcement.
• Double criminality is not required for 32 listed categories of offences where the relevant maximum custodial penalty is at least three years in the issuing state.
• The executing judicial authority has a limited but important role. It does not retry the case or ordinarily reassess the evidence, but it must examine the legal conditions for surrender and applicable grounds for refusal.
• Mandatory and optional refusal grounds are established by Articles 3, 4, and 4a of the Framework Decision. They include amnesty, ne bis in idem, age, certain limitation issues, and safeguards relating to convictions in absentia.
• Fundamental rights constrain mutual recognition. The CJEU’s judgments in Aranyosi and Căldăraru and LM demonstrate that serious risks concerning detention conditions or judicial independence may require individual examination.
• The European Investigation Order facilitates the gathering of evidence in another participating Member State and can be used for a broad range of investigative measures.
• The e-Evidence package provides European Production Orders and Preservation Orders for electronic evidence. Regulation 2023/1543 applies from 18 August 2026.
• Eurojust coordinates national investigations and prosecutions and helps resolve practical difficulties and conflicts of jurisdiction.
• The EPPO investigates and prosecutes offences affecting the financial interests of the EU within its defined competence. It is not a general European prosecution authority for all serious crime.
• Regulation 2018/1805 facilitates cross-border freezing and confiscation of criminal assets, while Directive 2024/1260 strengthens the broader asset recovery framework.
• Prisoner transfer and recognition of criminal judgments are governed by separate mutual recognition instruments, including Framework Decision 2008/909/JHA.
• Regulation 2024/3011 on the transfer of criminal proceedings applies from 1 February 2027.
• Procedural rights are indispensable. Interpretation, information, legal representation, legal aid, the presumption of innocence, and special safeguards for children form part of the EU criminal justice framework.
• The territorial application of EU instruments varies. Denmark and Ireland do not participate in every measure, and the legal position must be checked instrument by instrument.

20. Frequently Asked Questions

1. What is judicial cooperation in criminal matters in the EU?

It is the system through which Member States cooperate in investigating, prosecuting, and enforcing criminal decisions in cases involving more than one jurisdiction. It includes the surrender of suspects, gathering of evidence, recognition of criminal judgments, freezing of assets, and coordination between national authorities.

2. What is the legal basis for judicial cooperation in criminal matters?

The principal Treaty provisions are Articles 82–86 TFEU. Article 82 establishes mutual recognition and procedural cooperation, Article 83 concerns the approximation of substantive criminal law, Article 84 addresses crime prevention, Article 85 provides for Eurojust, and Article 86 establishes the legal basis for the EPPO.

3. What is the European Arrest Warrant?

An EAW is a judicial decision issued by one Member State requesting another Member State to arrest and surrender a person for prosecution or the execution of a custodial sentence or detention order. It is governed by Framework Decision 2002/584/JHA and has operated since 1 January 2004.

4. Is a European Arrest Warrant the same as extradition?

No. Traditional extradition generally operates through international treaties and national extradition law, often involving diplomatic or executive authorities. The EAW is a judicial surrender mechanism based on mutual recognition and direct cooperation between judicial authorities in participating Member States.

5. Can a person be surrendered for an offence that is not a crime in the executing country?

Yes, in certain circumstances. For the 32 categories of offences listed in Article 2(2) of the EAW Framework Decision, double criminality does not have to be verified if the offence satisfies the applicable maximum penalty threshold of at least three years in the issuing state. For other offences, double criminality may remain relevant.

6. Can an EAW be refused?

Yes. The executing judicial authority must refuse execution in the mandatory circumstances specified by Article 3 and may refuse it on the grounds listed in Articles 4 and 4a. These include certain cases involving amnesty, previous final judgments, age, limitation periods, territorial jurisdiction, and convictions in absentia.

7. Can a person challenge an EAW on human rights grounds?

Yes. The EAW must be applied consistently with the Charter of Fundamental Rights and the European Convention on Human Rights. A person may raise relevant fundamental rights concerns, including a real risk of inhuman or degrading treatment or a serious threat to the right to a fair trial. The executing authority must assess the matter according to the applicable EU law and CJEU case law.

8. What happens if the requested person consents to surrender?

If the person gives valid and informed consent, the executing judicial authority should generally decide on surrender within ten days. Consent may accelerate the procedure, but it must be voluntary and given with awareness of its legal consequences.

9. How long can EAW proceedings take?

The Framework Decision generally requires a final decision within ten days of valid consent or within 60 days of arrest where the person does not consent. An extension of up to 30 additional days is possible in specified circumstances. The actual duration depends on the complexity of the case and applicable procedural requirements.

10. What is the European Investigation Order?

The EIO is a judicial decision under Directive 2014/41/EU requesting another participating Member State to carry out a specific investigative measure or provide existing evidence. It can be used for witness interviews, banking information, certain forms of surveillance, and other measures permitted by the Directive.

11. What is the difference between an EAW and an EIO?

An EAW seeks the arrest and surrender of a person for prosecution or enforcement of a custodial sentence. An EIO seeks evidence from another Member State. Both are based on mutual recognition, but they address different stages and purposes of criminal proceedings.

12. What is Eurojust?

Eurojust is the EU Agency for Criminal Justice Cooperation. It supports coordination between national prosecutors and judicial authorities, particularly in serious cross-border cases. It facilitates joint investigations, assists with EAWs and EIOs, and helps resolve conflicts of jurisdiction. It does not replace national prosecution services.

13. What is the European Public Prosecutor’s Office?

The EPPO is an independent EU prosecution office responsible for investigating and prosecuting offences affecting the financial interests of the Union. It operates in participating Member States and has powers to bring cases before national courts within its defined competence.

14. Does the EPPO prosecute all serious crimes in the EU?

No. Its competence is limited principally to offences affecting the financial interests of the EU, as defined by Regulation 2017/1939 and the PIF Directive. Other serious crimes remain primarily within the competence of national authorities, although Eurojust and other EU mechanisms may support cross-border cooperation.

15. Can criminal assets be frozen in another Member State?

Yes. Regulation (EU) 2018/1805 establishes mutual recognition of freezing and confiscation orders in criminal matters. It enables a Member State to request the recognition and execution of qualifying orders in another participating Member State, subject to legal safeguards and limited grounds for refusal.

16. Does the EU have common rules protecting suspects and accused persons?

Yes. Several directives establish minimum procedural safeguards, including rights to interpretation and translation, information, access to a lawyer, legal aid, the presumption of innocence, and special protection for children. These safeguards apply within the scope and conditions of the relevant instruments.

17. Does the EAW apply between the EU and the United Kingdom?

No. The UK is no longer part of the intra-EU EAW system as a Member State. Surrender between the UK and EU Member States is governed principally by the extradition arrangements in the EU–UK Trade and Cooperation Agreement and the relevant national implementing laws.

18. Does the European Investigation Order apply in every EU Member State?

No. Denmark and Ireland are not bound by Directive 2014/41/EU. Other forms of international legal assistance may be required in relations involving those countries.

19. What is the transfer of criminal proceedings Regulation?

Regulation (EU) 2024/3011 establishes common rules for transferring criminal proceedings from one Member State to another where the proper administration of justice would be better served by conducting proceedings in the requested state. It applies from 1 February 2027.

20. Does mutual recognition mean that national courts must always trust foreign judicial decisions?

No. Mutual recognition is the general principle, but it is subject to the safeguards established by EU law and fundamental rights. The Court of Justice has confirmed that specific evidence of a real risk of serious rights violations may require further examination before surrender or execution takes place.

Conclusion

Judicial cooperation in criminal matters is one of the most ambitious expressions of the European Union’s legal integration. It seeks to address the reality that criminal conduct increasingly crosses national borders, while the institutions responsible for investigating and prosecuting offences remain predominantly national.

The European Arrest Warrant transformed the traditional relationship between extradition and national sovereignty by replacing much of the conventional diplomatic process with direct judicial surrender. The European Investigation Order and the e-Evidence framework extend cooperation to the collection and preservation of evidence. Eurojust provides a permanent structure for coordinating national investigations, while the European Public Prosecutor’s Office represents a more integrated model of prosecution within the specific field of offences affecting the Union’s financial interests.

The mutual recognition of freezing, confiscation, custodial sentences, and other criminal decisions further demonstrates that European cooperation extends beyond the arrest of suspects. It encompasses the practical enforcement of criminal justice across jurisdictions.

Yet the effectiveness of this system depends on a principle that cannot be reduced to administrative efficiency: the protection of fundamental rights. Mutual trust must be earned through functioning independent courts, fair proceedings, lawful detention conditions, and effective remedies. The judgments of the Court of Justice concerning detention conditions and judicial independence demonstrate that mutual recognition is not an absolute obligation detached from constitutional guarantees.

The European Union has not created a single criminal justice system. It has developed something more complex: a legal framework in which national criminal justice systems remain distinct but are increasingly interconnected through common rules, judicial cooperation, and institutional coordination. The balance between national autonomy and European integration is therefore central to the future development of this field.

Ultimately, the legitimacy of EU criminal cooperation depends on achieving two objectives simultaneously. Criminal activity must not be able to exploit national borders to escape investigation or punishment, but neither should the pursuit of effective enforcement weaken the rights of the individual. A European area of justice can be genuinely secure only when cooperation is accompanied by legality, proportionality, judicial independence, and respect for human dignity.

Primary Legal Sources and Further Reading

Treaty and constitutional foundations

• Treaty on the Functioning of the European Union – Articles 82–86
• Charter of Fundamental Rights of the European Union

European Arrest Warrant and surrender

• Council Framework Decision 2002/584/JHA – European Arrest Warrant
• European Commission – European Arrest Warrant
• EU–UK Trade and Cooperation Agreement

Evidence and digital cooperation

• Directive 2014/41/EU – European Investigation Order
• Regulation (EU) 2023/1543 – European Production and Preservation Orders
• Directive (EU) 2023/1544 – E-Evidence Legal Representatives

Institutions and asset recovery

• Regulation (EU) 2018/1727 – Eurojust
• Regulation (EU) 2017/1939 – European Public Prosecutor’s Office
• Regulation (EU) 2018/1805 – Freezing and Confiscation Orders
• Directive (EU) 2024/1260 – Asset Recovery and Confiscation

Procedural rights and transfer of proceedings

• Directive 2010/64/EU – Interpretation and Translation
• Directive 2012/13/EU – Right to Information
• Directive 2013/48/EU – Access to a Lawyer
• Directive (EU) 2016/343 – Presumption of Innocence
• Regulation (EU) 2024/3011 – Transfer of Criminal Proceedings

Judicial institutions and case law

• European e-Justice Portal – Criminal Cases
• Eurojust
• European Public Prosecutor’s Office
• CJEU – Aranyosi and Căldăraru, Joined Cases C-404/15 and C-659/15 PPU
• CJEU – LM, Case C-216/18 PPU

This article is intended for educational and informational purposes. The application of a particular instrument depends on its material, temporal, and territorial scope, the national implementing legislation, and the circumstances of the individual case.