Starting with these premises, I shall first analyse which methods guide the collection of transnational evidence in national countries and what human rights protection they provide where interferences with fundamental rights are required. To this end, I have selected four European countries, i.e., Germany, Italy, Spain and Switzerland, that will be analysed first separately and then comparatively.

After the Lisbon Treaty, EU institutions immediately announced important innovations in the field of transnational investigations and taking evidence abroad. Shortly before the entry into force of the Lisbon Treaty, the European Commission had already launched an ambitious challenge for overcoming the limits of the FD EEW. In its Communication “An area of freedom, security, and justice serving the citizens”,³⁹ it proposed the setting up of a comprehensive means of collecting evidence and envisaged the establishment of minimum principles to facilitate the mutual admissibility of evidence between countries, including scientific evidence. This approach was confirmed by the Green Paper of 11 November 2009, in which the Commission launched an ambitious proposal, aimed at covering a much more complex area than that covered by the legal instruments existing at that time, i.e., both the obtaining of evidence in criminal matters by one Member State from another and the securing of its admissibility in the criminal process that makes use of the evidence. The Commission drafted a distinction between two types of dynamic evidence, i.e., (a) evidence that, although directly available, can be obtained only through procedural activities (interviews of witnesses or suspects, wiretapping, bank accounts, etc.) and (b) evidence that, though it exists, requires further investigation or examination (analysis of existing objects, documents or data or obtaining of bodily material, such as samples or fingerprints). Although this distinction clearly relates to intrusive investigative means, however, the Commission’s approach in dealing with these measures remained unclear and the focus seemed to be addressed to investigative non-coercive means only to exclude the application of some grounds for refusal of assistance.

After the entry into force of the Lisbon Treaty, the Stockholm Programme of 11 December 2009 re-affirmed the need to bring order to the fragmentary regime of the existing instruments.⁴⁰ And along these lines, the Commission proposed, in its Action Plan Implementing the Stockholm Programme, two legislative initiatives planned for 2011. These initiatives have, however, never been launched, since they were anticipated by eight member states, which in April 2010 presented the ambitious legislative proposal of setting up a comprehensive tool of overseas investigations aimed at gathering almost any type of evidence, including non-documentary and dynamic evidence, i.e., the proposal for a Directive on a new European investigation order (EIO).⁴¹ The genesis of this text has been slow and turbulent, however. Starting in April 2010, examination by the Council lasted more than 1 year; a general agreement on the proposal was not reached until December 2011.⁴² After the orientation vote of May 2012 by the European Parliament, furthermore, the Conference of Presidents decided in June 2012 that the European Parliament would suspend its cooperation with the Council, inter alia, on the EIO dossier until a satisfactory outcome was achieved on Schengen governance.⁴³ Cooperation re-commenced in 2012, but the negotiations among the Council, the Parliament and the European Commission lasted up to November 2013, thus ending up in a compromise text.⁴⁴ After its confirmation by the Permanent Representatives Committee on 3 December, the EP Committee on Civil Liberties, Justice and Home Affairs voted on the text on 5 December 2013 and on 7 March 2014, after almost 4 years of long examinations, the Directive was finally issued.⁴⁵

A short look at this long path clearly shows that the text has been largely amended. To be sure, the original draft was not entirely consistent with its ambitious goal of launching a new form of mutual recognition resulting from the combination of the order model with the flexibility of the traditional MLA system—a goal that, moreover, encompassed the achievement of a high level of protection both of state-related interests and individual rights. Despite these aims, the original proposal had drastically reduced the grounds for refusal, which significantly restricted the margins of discretion of the executing authority while threatening both national sovereignty and the sphere of human rights.⁴⁶ As has been observed, furthermore, the original proposal had already dropped the emergency brake, introduced by the FD EEW, concerned with the use of coercive means: the executing authority was not left free to decide whether to enforce compulsory measures and, even worse, the choice of which investigative means, including intrusive means, to apply was left, in line with the approach of the proposed instrument, to the issuing authority. Nor did the original draft reproduce the clause, introduced by the FD EEW, banning the issuing authority from compelling the executing authority, by requesting the fulfilment of procedures of its own law in the collection of evidence, to apply coercive methods.

To be sure, the intrusiveness of the investigation abroad clearly emerged from several provisions, and it is therefore no surprise that in the course of the Council examination not only were new grounds for refusal re-introduced (e.g., the principle of ne bis in idem), but furthermore article 10(1) was re-structured, and a two-tier list of grounds for refusal was set up just on the basis of the distinction between coercive and non-coercive measures.⁴⁷ Although the final text has not reproduced this solution in the same terms, it has maintained a two-track system, based on a distinction between “normal” investigative measures and (among others) non-coercive measures, which “always have to be available under the law of the executing State” [art. 10(2)] and to which two of the normal grounds for refusal do not apply, i.e., the dual criminality requirement (unless the EIO has been issued in relation to one of the serious crimes listed in Annex D) and the respect for the limitations provided for by the law of the executing state and concerned with certain punishment thresholds or types of crimes [art. 11(2)].

This approach still displays a complicated construction, which gives rise to many human rights concerns. The fact that the measures of article 10(2) are provided for in an exhaustive list and that the grounds for refusal have been re-unified in a comprehensive list clearly demonstrates that the new investigative tool—unlike the old EEW—can normally impinge on fundamental rights. However, the very different regulation applicable to cross-border investigations and especially the heterogeneous nature of the measures listed in article 10(2) still do not make it possible to clearly understand what is to be meant respectively by “coercive measures” and “non-coercive means” in modern transnational procedures and which principles must govern their use.⁴⁸ For instance, hearings of witnesses or experts, despite not being included among “non-coercive measures”, are subject to the same regulations: as a consequence, they can be conducted irrespective of whether the act constitutes a criminal offence also under the law of the executing state and therefore without the guarantees that this law provides for in cases of criminal investigations.⁴⁹ On the contrary, investigative orders concerned with hearings by videoconference or other forms of audio-visual transmission may seem to be subject to the conditions set out for normal investigative means: thus, they may be refused in (all) the cases provided for in article 11, and witnesses and experts must be granted, among others, the right not to testify, which they would have under the law of either the executing or the issuing State.

This example shows in very clear terms how outdated the notion of “coercion” is, since both in domestic and transnational procedures it is no longer able to display the multiple forms of interference with the sphere of individual rights, forms not necessarily concerned with the intrusion in, or restriction of, fundamental rights. In this light, the new instrument still lacks a coherent, comprehensive vision of investigative interferences with fundamental rights. Upon close examination, the topic of fundamental rights protection still appears in a negative manner as a limit to efficient transnational prosecutions⁵⁰ rather than as a balancing element and condition for the achievement of fair transnational prosecutions.

As has been noted, the insertion of non-coercive investigative measures into the provision allowing the recourse to another measure, i.e. as a limit to this power, leads to the result that these must always be available under the law of the executing state, even if they entail an interference with individual rights, albeit without the use of coercion in a strict sense. In this regard, a particularly worrying issue is the importance attached by the new legislative tool to the collection of evidence already available for the issuing authority. Since the Council general agreement of December 2011, this mode of gathering evidence has appeared among the main aims of the new instrument [art. 1(1)], which will therefore encompass the scope of application of the old EEW. It is noteworthy, moreover, that in the final text obtaining available information appears at the top of the list of the (non-intrusive) investigative activities that must always be available in the executing country. This approach means underestimating the repercussions of this way of collecting evidence on the individual rights sphere. The decision of the issuing authority to request the transfer of evidentiary information already obtained in the executing state excludes any form of control of the overseas investigation by the defence. The general acknowledgement of this mode of obtaining evidence, furthermore, entails the risk of leaving enormous leeway to the issuing authority in choosing whether to order foreign authorities to conduct overseas investigations by means of an EIO or to order them to transfer the information obtained there, often in response to an informal request to do so. However, the modes of obtaining evidence abroad clearly cannot depend upon the discretion of the competent authority, nor can they be chosen irrespective of the link of the involved countries with the alleged offence.

On a deeper level, furthermore, the choice to exclude, in relation to this mode of obtaining evidence, the assessment of dual criminality and the respect for the criminal law requirements established by the law of the executing state shows that the incorrect application of the logic of division of labour, typical of the mutual recognition era, can give rise to serious lacunas in the protection of fundamental rights. This is principally because here the order is concerned with the taking of evidence rather than with the conduction of an investigative measure, which consists in the simple movement of evidence from one state to another—evidence, moreover, collected prior to, and independently from, the EIO procedure and possibly in the context of proceedings with a different subject and often of a different nature. Although evidence was taken in the executing state by means of an investigative measure (e.g., interception of telecommunications) in compliance with the legal requirements provided for by its procedural law in the proceedings for offence A, the free transfer of this evidence to another state by means of the EIO procedure, initiated in the proceedings for offence B, which does not even constitute a criminal offence in the executing state, exposes defendants to the risk of a criminal liability that they would not have run if the prosecuting authority had required the same measure to be conducted abroad. The same applies where the act in respect of which the EIO has been issued, albeit constituting a criminal offence under both legal systems, allows the investigative measure under the law of the issuing state but not under that of the executing state. In both cases, the failure to give relevance to these fundamental requirements will allow for the national authority receiving investigative orders to ignore the repercussions that the simple transfer of evidence can entail upon the sphere of individual rights in the criminal proceedings carried out in another member state.

To this end, it can be doubted that respect for individual rights can be ensured by the general provision allowing for the executing authority to refuse the execution of the EIO that would be incompatible with the executing state’s obligations under article 6 TEU and the EU FRCh [art. 10(1)(g)]. The introduction of fundamental rights clauses seems to be a rather programmatic way of acknowledging their value, which does not entirely correspond to specific regulations, especially on the methods of obtaining transnational evidence.

Upon close examination, the general duty to refuse assistance in the event of a breach of a fundamental right (or defence rights) may seem to be subject to the discretion that inspires all the situations listed in article 11(1), some of which, moreover, entail clear risks for individual rights. As a consequence, the executing authority is entitled to carry out the sought investigation, thus eventually impinging upon the fundamental rights either of the defendant or of third parties, notwithstanding the accused has been finally judged in the issuing state or in another country of the EU area. Even the fact that the act in respect of which the EIO has been issued was committed outside the issuing state and wholly in the executing country does not ban the executing authority from carrying out a (coercive) measure against the defendant, who may be a citizen of, or permanently resident in, the executing country and have legitimately trusted the lack of criminal relevance of their action—a conclusion that endangers both the requirement of legal certainty and EU principle of non-discrimination.

Furthermore, although the final text has dropped the proposed recital 12aaa, according to which member states “should ensure cooperation without endeavouring themselves to assess the respect of Union law and fundamental rights by the other Member States”, the commitment required from the cooperating authorities in ensuring respect for individual rights in transborder inquiries still appears to be generic. Starting with “a presumption of compliance by other Member States with Union law and, in particular, with fundamental rights”, a presumption rebuttable only where there are substantial grounds for believing that the execution of the EIO would entail the breach of a fundamental right as established in the EU FRCh,⁵¹ the Directive shows that EU institutions are still far from the idea of shared responsibility in ensuring full respect for individual rights in transnational investigations.⁵² This is probably because they are far from conceiving international cooperation as part of a comprehensive transnational prosecution, which therefore entails an overall protection of the defendants and all individuals involved.⁵³ In order not to abandon the requirements of the mutual recognition system, this way of realising a division of labour—far from granting individuals a level protection of their rights similar to that they enjoy in national cases⁵⁴—is still conceived as a means for offloading onto the cooperating authorities the burden of ensuring respect for individual rights within their own sphere of competence.⁵⁵

These conclusions also apply to the methods of conducting the investigation and taking evidence in another member state. In this regard, the EIO Directive, by reproducing the typical combined mode of obtaining evidence, demonstrates the need for a multicultural approach in the application of criminal procedural law in the field of transnational inquiries. What EU legislation still lacks, however, is a virtuous interaction between the national systems of human rights protection involved in the transnational procedure—a deficiency that the order model has surely inherited from the last phase of the MLA system. As we will see, the solution of combining lex loci and lex fori upon the condition of consistency with the fundamental principles of the executing country cannot ensure a harmonised complementation of the two procedural laws, since it can seriously alter the balances of interests pursued by the domestic laws. This applies firstly to lex loci due to the obligation of the executing authority to comply with foreign requirements that might even be “unfamiliar”⁵⁶ with its own law. Nor does this solution, which is clearly aimed at fulfilling the needs of lex fori to facilitate the admissibility at trial of evidence in the relevant proceedings,⁵⁷ ensure a proper application of lex fori. Despite the fact that suspected or accused persons (as well as their lawyers on their behalf) are entitled to request the execution of an investigation order (moreover within the limits and where provided for by national procedural law) [art. 1(3)] and despite the explicit reference to the need to respect the right to defence among the states’ obligations that the new instrument cannot modify [art. 1(4)], there is still no trace of any possibility for private parties to take part in investigative activities in a manner remotely comparable to participation allowed to (prosecution) authorities of the executing country. Thus, departing from the approach of the old MLA instruments, the Directive has failed to provide for any form of participation of private parties of the relevant proceedings in the execution of the requested measure—a lacuna that does not only impinge on defence rights but also shows the underestimation of the defence’s contribution to securing the correct application of its own law.

There is little doubt that a clear acknowledgement of the new mode of transnational evidence gathering has derived from the enactment of legal regulations for setting up joint investigation teams and obtaining evidence by means of them. It has been observed that this model has not developed in the context of the order model, surprising as it might be that the free movement of judgements and judicial products has not led to establishing a free flow of law enforcement officials from one member state to another.⁵⁸ As we have seen, joint inquiries clearly developed from the model of extraterritorial inquiries,⁵⁹ and it is noteworthy that the first international instrument that provided a general legal framework for joint investigation teams in Europe was the EUCMACM, which, moreover, marked a significant cultural change in the way extraterritorial investigations can be carried out. As a consequence of this approach, albeit still based on the request model rather than on the order model,⁶⁰ the authorities of more than one member state could ordinarily carry out joint investigative activities clearly affecting fundamental rights.⁶¹

Concerning the modes of taking evidence, all the international and supranational legislation that has regulated the conduction of joint investigations over the last two decades,⁶² while reproducing the approach of the EUCMACM, has returned to a rather strict application of the (procedural) law of the State in whose territory the team operates.⁶³ This has marked a highly territorial conception of procedural law—a conception only mitigated in the first instruments that governed the conduction of joint investigations, such as the EUCMACM and the FD JIT, by providing for the possibility that members of the team other than its leader can, when carrying out their tasks, take into account the conditions set by their own authorities in the agreement on setting up the team.⁶⁴

This approach, which entrusts the establishment of investigative methods to case-by-case agreements, entails many risks both for the efficiency of cross-border prosecution and for the rights of the individuals involved in transnational inquiries. Thus, provisions such as those of the EUCMACM and the FD JIT manifestly leave great uncertainty as to the procedures that must be followed and the limits to the investigative powers, since they neither allow for the addressees of the investigative activities to know exactly what conditions may be required nor clarify how these can be made compatible with lex loci.

To avoid these shortcomings, a second generation of international instruments, while decoupling the joint inquiries from the mode of legal assistance, has tightened the application of lex loci, thus requiring the application of the same standards of obtaining evidence to domestic procedures.⁶⁵ At a national level, some domestic legislation has adopted a similar solution,⁶⁶ while other regulations have posed legal limits on the power to agree conditions on evidence gathering in the context of joint investigations, in the sense that the national law of the member of the team in a secondary position provides a limit to the tasks that can be required of them.⁶⁷ Nevertheless, the application of lex loci as basis for any activity conducted by the team can give rise to a plethora of evidential laws in all cases in which the team operates in the territory of more than one Member State.⁶⁸ This solution constitutes neither an efficient nor a proper solution in a common area of freedom, security and justice, since it not only multiplies the risk of incompatibility of the evidence collected with lex fori and therefore the risk of its inadmissibility in one or more national procedures,⁶⁹ but it can also expose individuals to similar investigative powers interfering with their rights in a possibly different manner according to the State in whose territory the team operates, thus undermining the individuals’ trust in legal certainty.

In sum, both these approaches (free agreements on the forms of taking evidence and the application of the sole lex loci) give rise to serious concerns from a human rights perspective. Not only does the mode of joint inquiries not satisfy the need for legal certainty as to the evidentiary procedure, but it likewise returns to an even more territorial conception of transnational procedures than that of both the request and the order models, even where the investigations require a coordinated action spread over the territory of many member states—a solution that does not take into due account the trust both of the defendant and the addressee of the investigation in criminal procedural law. And one might argue that this approach has defeated one of the main challenges of joint inquiries, i.e., the creation of an integrated procedure that, by achieving a new balance among competing values, can properly fulfil the (individual rights) needs of the legal (constitutional) systems of the cooperating authorities.

Another model provides an alternative to both of the request and order systems. This model shows a highly original approach, which, starting with the assignment of the prosecutorial competence, also entails, moreover, the power of the competent authority of a single State to investigate directly abroad pursuant to the sole lex fori.

Historically, this approach has developed in some federalist contexts, providing an interesting way of obtaining evidence in other provincial states. In Europe, Switzerland adopted this model up to the new StPO of the Helvetic Confederation,⁷⁰ thus overcoming the multitude of cantonal procedural legal systems by allowing the competent authority to carry out direct investigations over the whole Helvetic territory under its own law. This approach constituted the core idea of the 2006 project on the transnational procedural unity led by Bernd Schünemann —a project that, even after the entry into force of the Lisbon, has not lost its relevance, providing a useful alternative to the model of mutual recognition on the basis of the assumption that European transnational inquiries require a single, coherent set of procedural rules that cannot be ensured through the combined application of two or more (possibly different) procedural laws.⁷¹ Also here, the proposed model is based on the concentration both of prosecutorial and investigative powers in one single member state. This result would be achieved though a prompt assignment of jurisdiction, which in cases of multiple competences of more than one State should follow a two-step approach consisting of the combination of a fixed, hierarchised order of criteria with a flexible procedural solution based upon the focal point of the alleged offence. One of the most significant innovations of this model consists of the introduction of a new institution, i.e., Eurodefensor, whose tasks would include representing the defendant’s rights in the assignment of jurisdiction. This is a very delicate phase, since the assignment of jurisdiction would imply the attribution to the competent authority of the power to investigate throughout the EU. Moreover, the fact that investigations and the collection of evidence follow the sentencing state’s law would also make the admissibility of evidence a strictly national issue.⁷²

Certainly, the main merit of such a federalist model lies in the coherence sought not only by the assignment of the prosecutorial and investigative power to a single state but also by the application of a single procedural law to transnational investigations. These characteristics mark, however, the limits of this approach. Thus, it can be doubted that the choice to link prosecution, adjudication and investigation to a single authority and a single (both substantive and procedural) law can ensure coherence to any cross-border investigation, while properly satisfying the need for pluralism that is inherent in the most complex transnational inquiries. Especially in the most complex criminal actions, characterised by a multitude of single crimes committed by several people with different citizenships (and often resident in different countries), concentrating the prosecution in single jurisdictions for single offences, as we will see, seems to satisfy neither the need for procedural economy nor the defendant’s interest in avoiding multiple prosecution.⁷³ In addition to the difficulty of establishing the competent jurisdiction in relation to acts spread over the territory of several states, the solution of assigning the prosecutorial power to a single territorial jurisdiction can hinder the efficient prosecution of the entire criminal phenomenon.