At the beginning of June 2023, the Secretariat of the Network of National Experts on Joint Investigation Teams (JITs) published its Fourth JITs Evaluation Report since 2014, offering an overview of practical findings, lessons learned, and best practices in conjunction with the use of JITs over the past several years. The report is based on 82 evaluations completed by JITs practitioners between November 2019 and November 2022.

According to the report, a number of best practices regarding the setting-up phase of JITs could be identified:

• Early meetings between law enforcement and judicial authorities from the countries concerned;
• Flexibility regarding the location of coordination meetings;
• The early involvement of other authorities, Eurojust, and other relevant EU agencies and bodies;
• The involvement of liaison prosecutors where relevant;
• Flexibility regarding the language(s) of the JIT agreement;
• The early explanation of the national legal/judicial systems in order to pre-empt potential hindrances to cooperation.

For the operational phase, best practices identified include, for instance:

• Direct and continuous contact and exchange of information among JIT parties;
• The establishment of personal relationships between JIT members, and the appointment of contact points;
• The exchange of information on specificities of the different legal systems;
• The appointment of seconded members;
• The use of the same interpreters throughout the JIT;
• Coordination of media strategy;
• Communication about JIT funding;
• Mid-term evaluations of cooperation within the JIT;
• Extension of cooperation into the trial phase to allow for efficiency in additional gathering and sharing of information and evidence (if possible according to national legislation);
• The participation of victims of crime in the assessment process.

Other chapters of the Fourth JITs Evaluation Report describe Eurojust's experience with multilateral JITs. There is also a dedicated checklist in all EU official languages, which gives an overview of what needs to be taken into account in the setting-up and operational phases of a multilateral JIT. Lastly, the report presents general figures as well as important innovations, trends, and new practices in the functioning of JITs. It also provides insight into judicial decisions into how some Member States tackled JITs-related issues.