Double Jeopardy at the European level; Principle or Market Practicality?

8th Nov 2022


On Friday 28 October 2022 the European Court of Justice prevented the extradition of a Serbian national from Germany to the USA on the basis that he had previously been convicted and sentenced for the same offences in Slovenia. The court determined that Article 45 of the Convention Implementing the Schengen Agreement (CISA), regarding the ne bis idem (double jeopardy) principle, overrode the terms of an extradition treaty between Germany and the USA. The ECJ found this to be the case despite the requested person being a non-EU national.

The Facts

The Serbian citizen, identified as HF, was convicted in Slovenia in 2012 for the offence of “attacking information systems” between December 2009 and June 2010. He was sentenced to one year and three months’ imprisonment, later commuted to 480 hours of community service, which he served in full by 25 June 2015.

On 4 December 2018 the US District Court for the District of Columbia issued an arrest warrant against HF concerning charges of “conspiracy to participate in racketeer influenced corrupt organisations and conspiracy to commit bank fraud and fraud by means of telecommunication” and an INTERPOL Red Notice was issued.

HF was arrested in Munich on 20 January 2022, with the USA submitting an extradition request on 17 March 2022. A previous extradition request made by the US to Slovenia in 2020 was rejected by the District Court of Koper, Slovenia on the basis that a Slovenian court had delivered final judgment in respect of the relevant acts. The US warrant included acts carried out after 2010, however the Slovenian authorities stated that there was no suspicion that any offence had been committed in respect of these acts.

As a result of the previous conviction the German court was uncertain as to the lawfulness of the proposed extradition to the USA and referred the question to the European Court of Justice.

The Question

The US extradition request was made under the auspices of the “Treaty between the Federal Republic of Germany and the United States of America concerning extradition” of 20 June 1978 (the Extradition Treaty). Under Article 8 of the Extradition Treaty “Extradition shall not be granted when the person whose extradition is requested has been tried and discharged or punished with final and binding effect by the competent authorities of the Requested State for the offence for which his extradition is requested.” Thus, Article 8 appears to only permit extradition to be refused in a case of double jeopardy where the previous conviction and sentence were imposed by Germany, and not any other EU member state.

The German court was concerned that this conflicted (in conjunction with Article 50 of the “Charter of Fundamental Rights of the European Union”) with Article 54 CISA which states that “A person whose trial has been finally disposed of in one Contracting Party may not be prosecuted in another Contracting Party for the same acts provided that, if a penalty has been imposed, it has been enforced, is actually in the process of being enforced or can no longer be enforced under the laws of the sentencing Contracting Party.”

The court sought the ECJ’s guidance as to whether Article 54 CISA overrode the provisions agreed in the Extradition Treaty, particularly in the case where the requested person is not an EU citizen. The court also queried whether, if Article 54 CISA took precedence, the effect would be that Germany would be unable to extradite a third-country national whose case had finally been disposed of in another Member State.

The Judgement

The ECJ first found that a request for extradition falls within the scope of prosecution referred to in Article 54 CISA “where such execution constitutes an act of a member state contributing to the effective prosecution of a criminal offence in the third country concerned.

The reference to “person” in Article 54 CISA did not distinguish between EU and non-EU citizens, and was only concerned with the jurisdiction in which the prior conviction and sentence had been located, not the nationality of the individual. Therefore, the relevant rules would apply to third country nationals, a conclusion which supported the objectives pursued by the provision.

The objective of the CISA provision is intended, as described in Advocate General Collins’ opinion in the case, “to ensure legal certainty through respect for decisions of public bodies that have become final, in the absence of harmonisation or approximation of the criminal laws of the member states.” It is also important to ensure that “a person whose trial has been finally disposed of in one member state can travel within the Schengen area without having to fear prosecution for the same acts in another member state” per the Judgement of the ECJ. Thus, the driving principle behind the provision may be seen to be to ensure the proper mutual and co-operative functioning of the various jurisdictions of the European Union. As AG Collins writes, “were it possible, in the area of freedom, security and justice, to bring multiple prosecutions against the same person for the same acts, the purpose of such an area would be defeated and the principles of mutual trust and mutual recognition of judicial decisions in criminal matters would be infringed.

As to the conflict with the Extradition Treaty, the ECJ found that member states must exercise their power in compliance with EU law and principles. The Court considered the Extradition Treaty to be subject to the separate extradition treaty between the EU, as a whole, and the US. Whilst that treaty does not specifically set out the ne bis idem principle as a reason to refuse extradition, it places an obligation on member states to follow EU law and principles, rendering them unable to conclude any treaty terms that conflict with these principles. AG Collins makes it clear that “member states are required to [act] in compliance with EU law and, more specifically, with the fundamental rights guaranteed by the Charter, including the principle ne bis in idem enshrined in Article 50 thereof, and cannot therefore enter into obligations which are incompatible with those arising under EU law

The ECJ’s focus on legal consistency throughout the EU area creates an interesting difference between the scope and application of double jeopardy rules at the EU level as opposed to national level, such as that applied in the UK.

Double jeopardy in the UK

The rule against double jeopardy in the UK is set out at sections 12 and 80 of the Extradition Act 2003 covering both EU member states and other countries respectively. Following Brexit the application of Part 1 of the Extradition Act may be reviewed, as has been discussed in this blog before, however the UK courts have upheld the applicability of this act as concerns member states to this date. Both s12 and s80 of the Extradition Act bar extradition “by reason of the rule against double jeopardy if (and only if) it appears that he would be entitled to be discharged under any rule of law relating to previous acquittal or conviction” by a UK court in purely domestic circumstances.

The UK rules, so engaged, fall into two categories; that of autrefois convict (or acquit) and the prevention of an abuse of process. Both principles apply where the original conviction was in a foreign jurisdiction as is set out in R v Thomas [1985] QB 604, where the accused had previously been convicted in Italy (although the UK court permitted that extradition as there was no prospect of punishment by the Italian court). Both principles were held to apply in extradition cases in Fofana & Belize v Deputy Prosecutor Thubin [2006] EWHC 744.

The autrefois bar applies where the accused is charged with the same offence in fact and law as the previous conviction (or acquittal). This is a narrow bar focussed on the legal basis of the charges brought, which must be the same, rather than merely arising from the same incidents. As Lord Morris of Borth-y-Gest states in Connelly v DPP [1964] AC 1254 “The test is […] whether such proof as is necessary to convict of the second offence would establish guilt of the first offence or of an offence for which on the first charge there could be a conviction.

The bar for abuse of process is somewhat broader, preventing extradition where the request arises out of the same or similar facts as the prior conviction. As Lord Devlin states in ConnellyAs a general rule a judge should stay an indictment [or per Fofana an extradition] when he is satisfied that the charges therein are founded on the same facts as the charges in a previous indictment on which the accused has been tried, or form or are a part of a series of offences of the same or a similar character as the offences charged in the previous indictment.

However, Lord Devlin did identify that not every second trial [or extradition] would always be an abuse of process. “The judge must then, in all the circumstances of the particular case, exercise his discretion as to whether or not he applies the general rule.” Therefore while the application of this bar may be broader, it might be challenged, for example where the previous sentence was unable to be applied, where new evidence has emerged or where new victims have been identified.

Principle v Politics

The differing approaches of the UK and EU courts lead to different effects. UK law is grounded in preventing the injustice or abuse of a second trial brought for the same offence or incident, while the European principle seeks to maintain a common legal framework and area within the community and to support the principle of freedom of movement.

While the double jeopardy principle is applied equally to all foreign jurisdictions with which the UK has an extradition treaty, the EU level principle in CISA only protects requested persons whose cases have finally disposed of in other member states, making it narrower in scope.

Similarly, whereas the application of the EU rule is as broad as the abuse of process bar in the UK, requiring only that the extradition be for “the same acts”, it is much more restrictive in the exceptions to that bar. Under Article 55 CISA, member states declare that they are not bound by Article 54 where:

  • The incident took place in whole or in part in their own territory
  • The offences constitute an offence against national security or equally essential interests of the member state
  • The acts were committed by officials of the member state in violation of the duties of their office.

Once again, the focus here is on mediating between the interests of member states, in creating a common legal area, rather than the UK focus on empowering  judges to decide whether it would be unjust to order extradition.


The recent ECJ judgement has further developed the EU wide ne bis idem rule at community level. However, being based on the international market rules framework of the EU, this principle is guided by the need to maintain integrity in the community rather than the application of the double jeopardy principle itself. As a result, this bar to extradition is limited in scope to convictions arising from other EU member states and assumes those convictions to be a complete bar to further prosecution save where to do so would create friction between member states.

Jasvinder Nakhwal
Tel: +44 (0) 20 7822 7753

Nick Vamos
Tel: +44 (0) 20 7822 7776