The Russian Federation-Ukraine conflict is a war that has posed an unprecedented legal, humanitarian and moral dilemma to both the national and the international criminal justice systems. The daily recording of numerous crimes against humanity, acts of violence against the civilian population, destruction of infrastructure and cultural heritage has highlighted the need to create an effective model of war crimes investigation, which would ensure not only the punishment of the guilty, but also the restoration of justice at the global level. This topic has not only legal, but also deep social significance, as it concerns the formation of trust in state institutions and international justice in the conditions of hybrid war and information pressure. The problem is that modern war crimes are committed on a scale and in forms that were not foreseen by the current norms of criminal law.

War crimes, their legal qualifications, and investigation should be based on the principles of international law of humanitarian and international criminal law. Specifically, the concept of war crimes is already defined in the Geneva Conventions of 1949 and the additional Protocols of 1977, which define how civilians, prisoners of war, and civilian objects must be treated in armed conflict. These are further elaborated in Article 8 of the Rome Statute of the International Criminal Court that stipulates the types of war crimes, and the international jurisdiction in prosecuting the war crimes. Ukraine has accepted the jurisdiction of the International Criminal Court under Article 12(3) of the Rome Statute, which allows the Court to exercise jurisdiction over crimes committed on its territory. As such, the investigation and proof of international crimes, including war crimes and crimes against humanity should not only be viewed in the context of the domestic criminal justice system in a country, but also in the context of the established universal legal principles.

Ukrainian law enforcement practice is for the first time faced with the need to document war crimes and other serious violations of international humanitarian law committed during the armed conflict, use digital technologies and OSINT sources in the process of proving, which requires updating both the methods of work of investigators and the legislative regulation of the criminal process. It is worth mentioning that the current work is more dedicated to the definition of war crimes based on the international humanitarian law, Article 8 of the Rome Statute of the International Criminal Court, whereas the crime of aggression is a separate category of international crime under the Rome Statute which refers more to the role of the political and military leadership of the state. Previous scientific works (Borovyk, 2024; Kovalchuk, 2024; Tymoshko, 2024; Shevchuk et al., 2025) highlighted certain aspects of the prosecutor’s office’s activities, crime documentation, and procedural coordination, however, a comprehensive vision of the interaction of the national system with international institutions, issues of admissibility of digital evidence, and ethical boundaries of its use remain insufficiently developed. A significant international legal background to the crime investigation practice in the Russian-Ukrainian war is the jurisdiction of the International Criminal Court (ICC). The jurisdiction of the Court has been accepted by Ukraine under Article 12(3) of the Rome Statute which gives the ICC the power to assert jurisdiction over the crimes committed on its territory. In March 2022 the Prosecutor of the International Criminal Court launched an investigation of the Situation in Ukraine (ICC-01/22) that includes the alleged war crimes, crimes against humanity, and genocide that occurred on the Ukrainian territory since 2014. ICC prosecutor Office is in the process of carrying out investigations in collaboration with authorities in Ukraine and other international partners. Thus, national war crimes investigations should therefore be conducted in coordination with the investigative mandate of the ICC.

The scientific value of the topic lies in the need for a theoretical generalization of the experience of Ukraine as a state that documents war crimes in real time, integrating legal, technological and humanitarian approaches. Given that international criminal law is actively transforming under the influence of the digital era (Wells, 2025; Popov et al., 2025; Eurojust, 2025), the Ukrainian case becomes a unique example of the practical implementation of new principles of evidence, cooperation between the state and civil society, as well as the use of artificial intelligence technologies and open data for collecting evidence. The theoretical significance of the study is determined by its contribution to understanding the role of digital forensics and international coordination in ensuring the rule of law, while the practical value is in the possibility of forming recommendations for improving national and interstate mechanisms for investigating war crimes. Despite numerous analytical publications, a unified approach to the qualification of crimes of aggression, assessment of the admissibility of OSINT evidence and protection of witness rights in wartime has not yet been developed (Hafetz, 2024; Chlevickaitė, 2025; Rassamakhina, 2025). The impact of international political narratives and communication strategies on perceptions of justice also remains under-researched (Tran Sautedé et al., 2025; Xu & Zhao, 2025). These blank spaces need to be analyzed systemically through interdisciplinary approach which integrates legal, ethical, technological, and social elements.

The aim of the research is to determine the characteristics of the inquiry and evidence of the war crimes under the circumstances of the Russian-Ukrainian war, define the specifics of the digital evidence base, examine the interplay of the national and international organizations in this sphere, and pinpoint issues that prevent the alignment of the Ukrainian criminal process with the international standards of justice. In this research, a war crime is a severe breach of the international humanitarian law that can be conducted in a period of armed conflict as described in the Geneva Convention of 1949 and Article 8 of the Rome Statute of the International Criminal Court. Among them, there are in particular attacks on civilian targets, the demolition of civilian facilities, ill treatment of prisoners of war, unlawful deportation of civilians and other acts that are forbidden by the laws and customs of war. It is important to note that the given study does not examine the crime of aggression as a separate set of international criminal responsibility, as the given crime involves the political and military leadership whose action is to initiate an act of aggression and which falls under a different jurisdictional rule under international criminal law.

Recent academic research on the investigation of war crimes in the context of the Russian-Ukrainian war focuses on the transformation of the national criminal justice system, the digitalization of the evidence base, and adaptation to international standards of justice. Considerable attention has been paid to the role of the prosecutor’s office and law enforcement agencies in documenting crimes of aggression, crimes against humanity, and violations of international humanitarian law (Borovyk, 2024; Kovalchuk, 2024; Tymoshko, 2024; Shepitko, 2022). The success of such investigations is determined by the harmonization of the law with the principles of international criminal law, the possibilities of pre-trial investigating organizations, and the introduction of the technological equipment in terms of gathering and storing evidence. (Martyniuk et al., 2025; Vyhivskyi et al., 2024). A significant contribution to the current discussion has been made by works devoted to proving war crimes using digital technologies, open sources and artificial intelligence analytics. According to the position of Wells (2025) and analysts of Eurojust (2025) and Europol (2025), OSINT materials, satellite data and digital forensics form a new level of evidentiary practice, which requires strict adherence to the principle of “chain of custody”. The use of open digital sources for evidence collection, which is actively supported by Ukrainian experts (KMA Law, 2024), contributes to the operational documentation of crimes, but raises questions about the authenticity and procedural admissibility of the materials (Popov et al., 2025; Shevchuk et al., 2025).

An important area of research is the analysis of the interaction between state and public institutions in the process of documenting war crimes. Research by Chlevickaitė (2025) and Rassamakhina (2025) demonstrate that the involvement of civil society organizations and volunteer networks expands the possibilities of collecting primary data, contributing to the transparency of investigative processes. In this regard, the importance of developing a system of ethical norms and healthy interaction of victims, investigators and analysts is underlined (ZMINA, 2025; JustTalk, 2024). The problems of international collaboration in the sphere of crime investigation are presented in the works of Hafetz (2024), Suhong and Tan (2024) and European Commission (2025), where it is discussed that the international structures, namely Eurojust, Europol and the International Criminal Court, play the role in ensuring the legal compatibility of evidence. The comparative experience analysis also demonstrates that Ukraine is developing its own vision of integration into the global justice system based on the principles of complementarity and digital transparency (Popov et al., 2025; Martyniuk et al., 2025; Hafetz, 2024; European Commission, 2025).

Another category comprises the studies that focus on empirical evidence of the investigation of war crimes and the phenomenon of judicial decisions (Reuters, 2022; 2024; Hunder, 2024; Peleschuk, 2025). The information provided by such sources presents a picture of the systematic overload of pre-trial investigation services, the creation of analytical centers and computer evidence infrastructure. The issues of procedural efficiency and inadequate coordination are also validated in the articles by Ochab (2025), Strok (2025) and Zhovtiuk (2025), who also stresses the necessity of international assistance and technologies. General theory of international criminal law and geopolitical discourses on the war in Ukraine are also not negligible (Chu, 2024; Tran Sautedé et al., 2025; Xu & Zhao, 2025; Zvobgo & Simmons, 2025). They enable us to comprehend the context of war crimes in a larger context as an instrument of information, warfare and political responsibility. Also, contemporary scientific sources are dedicated to the subjective dimension of the investigation of war crimes and their powers in criminal procedures. Specifically, Kosokhatko (2025) and Syvodіed (2025) also note that there are not enough specialists trained to operate in martial law, and that coordination between the investigators and prosecutors with the forensic experts is crucial. Researchers observe that the expediency of the evidence gathering and how well it is later evaluated by the law depends on the competence of the interaction between these entities (Strok, 2025; Zhovtiuk, 2025).

Certain works stress the need to establish trial monitoring mechanisms that will involve transparency in the process of addressing cases of war crimes. According to Ukrainian Bar Association (2023) and JustTalk (2024), a systematic study of court rulings provides an opportunity to trace the gaps in the system of application of the Article 438 of the Criminal Code of Ukraine, as well as the procedural issues in the admissibility of the evidence. These facts are parallel to the stance of Zhovtiuk (2025) who stresses that judicial practice is supposed to establish constitutive norms of justice in order to provide the principle of inevitability of punishment. Separately, it is worth mentioning the study of Tran Sautedé et al. (2025) and Xu and Zhao (2025), who analyze global information narratives about the war in Ukraine and their impact on the international legitimacy of criminal prosecution of the aggressor. Zvobgo and Simmons (2025) draw attention to public support for the idea of bringing to justice for war crimes in the United States, which reflects the importance of forming international legal solidarity. In the broader context of international justice, studies that analyze the creation of an international tribunal and historical precedents of war trials are also important (Chu, 2024; Glusman, 2024).

The term global justice system is also used in international criminal law to refer to a multi-level system that encompasses the international criminal courts, national judicial institutions and international legal cooperation mechanisms. One of the most important aspects of this system is the principle of complementarity that is provided by the Rome Statute of the International Criminal Court, according to which the investigation and prosecution of the international crime are the duty of states, but the International Criminal Court is a court of last resort, when the state is not able or willing to conduct a genuine prosecution. Hence, international criminal justice by itself, the International Criminal Court, international investigative and cooperation platforms including the joint investigation teams and international prosecutorial networks together constitute the global system of accountability over international crimes.

A number of studies are also devoted to the peculiarities of criminal proceedings, in particular, pre-trial investigation under martial law (Krushynskyi et al., 2023; Predmestnikov et al., 2024).

Thus, scientific publications cover both legal and technological, organizational and ethical aspects of war crimes investigation, which reflects the interdisciplinary nature of the problem. The issues of harmonizing national legislation with the norms of international criminal law and creating a single digital standard for evidence preservation remain unresolved. There are also no clear mechanisms for international coordination and ethical regulation of the use of digital evidence during war crimes investigation.

The research was carried out on the basis of a comprehensive analysis of regulatory legal acts, international agreements, judicial practice and official reports of Ukrainian and European institutions regulating the investigation of war crimes. The work used methods of comparative legal analysis to compare Ukrainian procedural approaches with the practices of the International Criminal Court and the institutions of the European Union (Eurojust, Europol, European Commission). Moreover, the comparative legal examination incorporated the review of the major international law tools on the war crime prosecution. Some of them include the Geneva Conventions of 1949 and Additional Protocol I (1977), the Rome Statute of the International Criminal Court (1998), and resolutions and reports of international organizations like the United Nations, the International Criminal Court, and the institutions of the European Union. The examination of these normative documents allowed defining the degree of alignment of the criminal procedural practice in Ukraine with the international standards of investigation, documentation, and the admissibility of the evidence in the war crimes cases. Reports of the Office of the Prosecutor General of Ukraine (2025) and analytical reviews of international human rights organizations were used (Media Initiative for Human Rights, ZMINA). The system approach method allowed to identify the relationships between the legal, technological and ethical aspects of the investigation of war crimes, and the inductive-deductive method ensured the formation of generalized conclusions based on the analysis of individual cases. The quantitative-analytical method was used to process statistical data on the number of registered criminal proceedings, reports of suspicion and indictments in 2022–2025. The source database was formed from scientific articles, official websites of international organizations and materials from academic journals, which ensured the reliability and objectivity of the research results.

The findings of the research are organized into three dimensions of analysis: (1) institutional and organizational realities of war crimes investigations in Ukraine; (2) the evidentiary paradigm and the place of digital and OSINT-based evidence; and (3) mechanisms of procedural and international cooperation during the investigation and prosecution of war crimes. This kind of structuring enables a systematic study of the relationship between national investigative agencies and mechanisms of international justice, and it is possible to identify any critical institutional and legal issues that can influence the efficiency of the investigations of war crimes.

The current state of war crimes investigations in Ukraine is characterized by unprecedented scale, legal complexity, and the need for synergy between national and international structures. Since the beginning of the full-scale invasion of the Russian Federation in 2022, Ukrainian pre-trial investigation bodies have been faced with the need to document crimes against humanity, war crimes, and the crime of aggression in real time, which significantly distinguishes the current experience from previous international precedents. However, the investigation and proof of war crimes constitute the primary focus of the present analysis of the current analysis, as the crime of aggression falls under various jurisdictional processes and is now under consideration in the field of establishing a special international tribunal. In March 2022 the Prosecutor of the International Criminal Court opened an investigation into the Situation in Ukraine (ICC-01/22) concerning alleged war crimes, crimes against humanity and genocide committed on Ukrainian territory (International Criminal Court, 2024).

Ukraine has turned into an experiment in terms of the modern methods of evidence collection in a territory of ongoing hostilities when legal, technological, and humanitarian issues are tightly interrelated (Borovyk, 2024). Development of interagency and international coordination mechanisms has been among the important areas. In this context, joint platforms such as the Joint Investigation Team (JIT) under the auspices of Eurojust, as well as Genocide Prosecution Network, which promotes standardization of approaches to war crimes investigation and evidence sharing between EU countries (Eurojust, 2025; Suhong & Tan, 2024). At the same time, Europol’s work on assessing transnational crime demonstrates the importance of integrating forensic databases and using analytical technologies to track structural features of war crimes committed systematically (Europol, 2025).

In Ukraine, significant powers in the investigation of war crimes are vested in the Office of the Prosecutor General of Ukraine (2025), which coordinates the actions of the police, the Security Service and other pre-trial investigation bodies. Practice shows that the main problems remain the overload of investigators, the shortage of forensic experts, as well as the technical inability to quickly check large amounts of digital evidence. At the same time, the involvement of public structures and volunteer networks in collecting primary data on crimes in the occupied territories has significantly expanded the evidence base (Chlevickaitė, 2025). A new aspect of documenting war crimes has been the widespread use of open digital data and OSINT technologies (Open Source Intelligence). Ukrainian and international researchers are actively using video, photo and satellite materials to geolocate events, verify testimonies and form evidentiary dossiers for further transfer to the International Criminal Court (KMA Law, 2024). Such a solution not only broadens the scope of forensic possibilities but also generates an additional problem of ensuring the credibility and legal validity of digital evidence (Wells, 2025).

It is also significant that in case of constant war, the investigation process is likely to be an amalgamation of legal work and the humanitarian mission. Many of the crimes committed against civilians get recorded through the assistance of international non-governmental organizations and journalistic associations, which give publicity and global attention to the crimes committed (Rassamakhina, 2025). Meanwhile, the documentation of war crimes is not only an evidentiary project, but it is also the establishment of collective memory and a historical archive of the war. Lastly, the practice of the international community shows that the successful investigation of crimes against humanity is impossible without the utilization of both professional and innovative types of cooperation between the state, civil society and the international partners. In this regard, the Ukrainian model turns out to be a singular experience of aligning international standards to the specifics of the modern warfare, including a decentralized system of data collection, focus on digital evidences and connectivity to international justice (Popov et al., 2025; Shevchuk et al., 2025).

The details of the application of evidence in criminal cases concerned with war crimes are defined by the transformation of the traditional principles of the collection, analysis and storage of evidence in the context of the magnitude of crime and the increased impact of digital technologies. In the conditions of the modern war in Ukraine, the main sources of evidence have become not only eyewitness accounts, documents or material objects, but also digital data – photos, videos, satellite images, surveillance camera recordings, social media content, geolocation data, etc. (Wells, 2025). This process requires highly qualified specialists, close coordination between state and international structures, as well as compliance with the procedural purity of evidence so that it can be used in international courts (KMA Law, 2024; Shevchuk et al., 2025).

Important empirical evidence of the dynamics of investigations is contained in the official statistics of the Office of the Prosecutor General of Ukraine. According to data for 2022–2025, the number of war crimes registered under Article 438 of the Criminal Code of Ukraine is 187,689 cases, of which only about 53–135 ended with a report of suspicion each year. From 24 to 47 proceedings were sent to court per year, while the number of victims exceeded 220 thousand people (Office of the Prosecutor General of Ukraine, 2025). This ratio confirms the scale of the problem: the law enforcement system is faced with a colossal burden, which requires automation of accounting, development of analytical infrastructure and increasing the staffing capacity of pre-trial investigation bodies.

Table 1 summarizes the main types of evidence, methods of obtaining it, and admissibility criteria for criminal proceedings.

Table 1

Type of evidence	Sources of receipt	Technological tools	Eligibility criteria	Main problems
Testimony of eyewitnesses and victims	Interviews, surveys, affidavits	Audio/ video recording, stenography	Voluntariness, reliability, procedural confirmation	Traumatic experiences of witnesses, risk of re-victimization
Photo and video evidence	Social networks, media, private archives	Metadata, geolocation, software verification	Identification of time, place, source	Manipulation or assembly of materials
Digital and satellite data	Satellite systems, geoanalytics	AI analytics, mapping services, object recognition algorithms	Compliance with preservation and chain of evidence standards	Data access and source verification
OSINT materials (open intelligence)	Internet, open databases, forums	Classification algorithms, image search	Verification, reproducibility	Unreliability of sources, fake content
Electronic communications	Phone records, messages, emails	Digital forensics, metadata analysis	Receipt by court order, confirmation of authenticity	Encrypting, deleting, or forging messages
Materials obtained using search intelligence	Facial recognition systems, text analysis	Machine learning, neural networks	Compliance with the principles of transparency, reproducibility of results	Ethical risks, algorithm errors, privacy

Source: created by the authors based on KMA Law, 2024; Wells, 2025; Shevchuk et al., 2025; Popov et al., 2025; Chlevickaitė, 2025.

The data presented shows that the use of digital technologies significantly expands the capabilities of forensics, allowing them to obtain evidence from open sources and conduct their multi-level verification. At the same time, the digital evidence base increases the risks of procedural violations – for example, interference with metadata, file changes or doubts about the reliability of the source. To ensure the legal admissibility of such evidence, Ukraine is gradually implementing international standards, including the requirements of the “chain of custody” and methods of digital certification of materials (Borovyk, 2024; Tymoshko, 2024). Thus, the development of digital forensics in the Ukrainian context not only increases the efficiency of the investigation but also creates the basis for building a new culture of evidence – flexible, technologically adaptive and ethically balanced. This process determines the strategic direction of the integration of the Ukrainian justice system into the international community, which requires harmonization of standards with the European Union and the International Criminal Court (Eurojust, 2025; Vyhivskyi et al., 2024).

The procedural support for the investigation of war crimes in Ukraine remains one of the most complex aspects of wartime criminal justice. Its issues combine issues of jurisdiction, evidentiary legitimacy, international cooperation, and compliance of national legislation with international standards. During the period of ongoing Russian aggression, the Ukrainian law enforcement system operates under constant strain, lack of resources, and the need to respond quickly to numerous crimes that have the characteristics of genocide, crimes against humanity, or violations of the laws and customs of war (Kovalchuk, 2024; Borovyk, 2024).

Ensuring procedural standards in such conditions requires pre-trial investigation bodies not only to comply with the norms of the Criminal Procedure Code, but also to adapt their work methods to the situation of martial law. In parallel, a system of interaction with international structures is being formed – the International Criminal Court, Eurojust, Europol and a number of non-governmental organizations that document crimes in the field. As the analytical review presented in Table 2 shows, the problems of procedural support and international cooperation can be grouped into main areas related to organizational, legal, technical and ethical factors.

Table 2

Problem direction	Essence	Manifestations in practice	International institutions / partners	Proposed solutions
Jurisdictional conflicts	Lack of full adaptation of national procedural norms to international criminal law	Difficulties in holding the top military and political leadership of the Russian Federation accountable	International Criminal Court (ICC), UN	Development of international mechanisms of accountability, including the ongoing initiative to establish a Special Tribunal for the Crime of Aggression against Ukraine under the auspices of the Council of Europe (Council of Europe, 2024).
Procedural overload	Excessive number of proceedings, lack of personnel and technical resources	Investigators and prosecutors are handling 1,000+ cases simultaneously	Office of the Prosecutor General, National Police	Creation of regional analytical centers, digitalization of evidence accounting (Vyhivskyi et al., 2024)
Insufficient international coordination	Lack of a single protocol for the transfer of evidence between states	Double checking materials, waste of time	Eurojust, Europol, Genocide Prosecution Network	Development of a unified format for the exchange of evidence (Eurojust, 2025; Europol, 2025)
Ethical and security risks	Use of traumatic testimonies, risk of disclosure of personal data	Repeated victimization of witnesses, compromising evidence	Human Rights Organizations, Media Initiative for Human Rights	Implementing ethical codes and confidentiality protocols (Rassamakhina, 2025)
Technical limitations	Imperfection of databases, limited access to international analytical systems	Loss of information, inability to verify authenticity	Europol, OSINT platforms	Development of a national platform for evidence of war crimes (KMA Law, 2024)
Insufficient participation of the civil sector	Formal interaction between state and non-state structures	Incomplete verification of evidence, duplication of materials	Civil society networks, ZMINA, JustTalk	Increasing transparency and mutual trust between state and non-state institutions (Chlevickaitė, 2025; ZMINA, 2025)

Source: created by the author based on Borovyk, 2024; Kovalchuk, 2024; Eurojust, 2025; Europol, 2025; Martyniuk et al., 2025; Vyhivskyi et al., 2024; Rassamakhina, 2025; KMA Law, 2024; ZMINA, 2025.

As can be seen from Table 2, the key difficulties lie not only in the legal plan, but also in the technical and moral-ethical dimensions. In addition, recent international initiatives aimed at establishing a Special Tribunal for the Crime of Aggression against Ukraine demonstrate the growing role of international institutional mechanisms in addressing accountability gaps for international crimes. The Ukrainian system of pre-trial investigation is simultaneously building its own model of integration into international justice, based on the principles of transparency, trust and evidentiary compatibility. However, its effectiveness directly depends on the degree of harmonization of national legislation with international criminal norms, as well as on the creation of a single digital evidence base that ensures traceability and verification of the origin of materials (Shevchuk et al., 2025).

Overall, the institutional capacity growth on a gradual basis may be observed in the process of coordinating the activities of the prosecutor office, the security services, the police and the human rights organizations. However, the maintenance of the procedural validity of evidence during the period of war is a complex question to which it is necessary to refer to law and to the managerial and technical measures as well. Therefore, international cooperation plays a structural role in the system of international criminal justice, as it enables the coordination of national investigations with the mechanisms of the International Criminal Court, joint investigation teams, and other international accountability mechanisms (Popov et al., 2025; Ochab, 2025).

The modern Ukrainian system of war crimes investigation is actively adapting to international standards, primarily to the practices of the International Criminal Court (ICC) and joint European mechanisms for cooperation in the field of criminal justice. Ukraine’s progress in this direction is significant: the state participates in the Joint Investigation Team under the auspices of Eurojust and Genocide Prosecution Network and also cooperates with Europol to provide analytical support to investigations (Eurojust, 2025; Europol, 2025; Suhong & Tan, 2024). At the same time, as analysts note, the issue of harmonizing procedural standards, establishing jurisdiction, and procedures for admissibility of evidence remains open (Hafetz, 2024).

It is in this respect that the use of national procedural rules interpretation must also be considered in the light of the norms which have been established in the Rome Statute of the International Criminal Court and the jurisprudence of international criminal tribunals, which determine the admissibility of evidence and its reliability in the conducting of war crimes.

A comparison of Ukrainian and European approaches allows us to identify the main differences in the system of evidence, in particular in matters of the legal framework, the chain of custody of evidence (chain of custody), international cooperation and procedural guarantees of the parties (European Commission, 2025; Suhong & Tan, 2024). A summary is given in Table 3.

Table 3

Parameter	Ukrainian approaches	European/international standards	Areas of harmonization
Jurisdiction and legal framework	Amendments to the Criminal Code and procedural legislation; harmonization of national norms with international criminal law	Full jurisdiction of the ICC, unified approaches to the crime of aggression (European Commission, 2025)	Gradual harmonization of criminal proceedings with international standards and expansion of cooperation with the International Criminal Court (Martyniuk et al., 2025)
Standards of proof	Use of digital, OSINT and satellite data, but lack of unified verification procedures	ICC and EU define clear rules for chain of custody, reproducibility, and admissibility of evidence (Hafetz, 2024; Wells, 2025)	Development of national protocols for the storage and transfer of digital evidence
International cooperation	Ukraine is actively involved in the JIT and cooperation with Eurojust, but faces resource constraints	The EU has standardized mechanisms for sharing evidence and joint investigation teams (Joint Investigation Teams). (Suhong & Tan, 2024)	Expanding cooperation with the ICC, concluding bilateral legal assistance agreements
Procedural guarantees and rights	Procedural rights are enshrined in the CPC, but wartime conditions make it difficult to comply with standards	European standards guarantee the presumption of innocence, the protection of witnesses and victims (Glusman, 2024)	Adaptation of procedures to martial law conditions; creation of a national witness protection system
Documenting the extent of crimes	Large array of cases, limited systematization of evidence	The EU supports the establishment of a Centre for the International Prosecution of the Crime of Aggression (European Commission, 2025)	Formation of a centralized database and integration with international structures (Vyhivskyi et al., 2024)

Source: was created by the author based on Eurojust, 2025; Europol, 2025; European Commission, 2025; Hafetz, 2024; Suhong & Tan, 2024; Martyniuk et al., 2025; Wells, 2025; Vyhivskyi et al., 2024.

Comparative analysis shows that Ukraine is gradually integrating European standards of evidence, especially in the areas of digital forensics and international cooperation. However, the key areas of harmonization remain the harmonization of national legislation with the norms of international criminal law, the creation of a national witness protection mechanism, the development of unified procedures for the “chain of custody” and the development of a digital evidence infrastructure compatible with the platforms of the International Criminal Court (ICC) and Eurojust. This will not only strengthen the procedural legitimacy of investigations, but also increase their international recognition (Popov et al., 2025; Shevchuk et al., 2025).

The authors conducted quantitative and analytical study. For this study, they used statistical data on the number of criminal proceedings, reports of suspicion, referrals of cases to court, as well as the number of victims of war crimes committed on the territory of Ukraine in the period from 2022 to September 2025. The information was obtained from publicly available official sources – reports of the Office of the Prosecutor General of Ukraine, the data of which generally coincides with the reports of international analytical agencies (Reuters, 2022, 2024; Hunder, 2024, Peleschuk, 2025), confirming their official origin.

Below (see Table 4) are summarized results of a quantitative and analytical study reflecting the overall dynamics of war crimes investigations in Ukraine in 2022–2025 based on official reports of the Prosecutor General’s Office.

Table 4

Period	War crimes were recorded (Article 438 of the Criminal Code of Ukraine)	Including those that caused the death of a person	Crimes for which the person has been notified of suspicion	Proceedings referred to court with indictment	Number of victims
2022	60.387	6.013	135	47	50.913
2023	60.944	1.844	88	37	72.728
2024	28.788	1.659	64	46	40.594
January–September 2025	37.570	1.564	53	24	57.289
Total (2022–2025)	187.689	11.080	340	154	221.524

Source: was created by the author based on Office of the Prosecutor General of Ukraine (2025).

An analysis of official data shows that over 187,000 war crimes were registered in four years, but in only a few hundred cases individuals were notified of suspicion and even fewer reached court. This imbalance between the number of crimes and the number of proven cases reflects the inefficiency of the existing evidentiary system, the lack of qualified personnel and the need to automate analytical processes. At the same time, the increase in the number of victims indicates the scale of the humanitarian consequences of the war and the need to create specialized units to support victims. These trends confirm the feasibility of developing digital forensics, centralized accounting of evidence and strengthening international partnerships in the field of war crimes.

Improving the system of proving war crimes in national law enforcement practice requires a comprehensive strategy that combines the adaptation of Ukrainian legislation to the norms of international criminal law, the development of institutional capacity and the introduction of modern technological tools. Simultaneously, it is necessary to note that Ukraine has already made some significant legislative measures in order to harmonize criminal laws with the Rome Statute of the International Criminal Court. New revisions of the Criminal Code have included the provisions of international crimes, and this enhances the national legal system of prosecuting war crimes. Nevertheless, additional work should be done on the criminal procedure and institutional practice level to secure the proper application of the principle of complementarity, as the international courts should have primary jurisdiction over international crimes, whereas the International Criminal Court is supposed to be a court of last resort (Martyniuk et al., 2025). It is necessary to create a national standard for collecting and verifying digital evidence, which will include a mechanism for confirming authenticity and an uninterrupted chain of custody (chain of custody), as well as certification of specialists in the field of digital forensics. Particular attention should be paid to protecting the rights of participants in the process – victims, witnesses, suspects – in accordance with Articles 14 and 15 of the International Covenant on Civil and Political Rights and the practice of the European Court of Human Rights. Development of national evidence databases, their synchronization with international platforms, in particular Genocide Prosecution Network and Joint Investigation Teams under the auspices of Eurojust will ensure transparency and increase trust in the results of investigations (Eurojust, 2025; Suhong & Tan, 2024; Vyhivskyi et al., 2024).

In addition to improving legislation and technical modernization, it is important to strengthen the human and educational potential of the bodies conducting pre-trial investigation and procedural guidance in war crimes proceedings. It is advisable to introduce a specialized training program for investigators, prosecutors and judges in international humanitarian law, proving war crimes and working with digital sources (Wells, 2025). The system should ensure effective interaction between state structures and civil society, in particular human rights organizations that carry out the initial recording of crimes in the de-occupied territories (Chlevickaitė, 2025). It is recommended to introduce an institutional model of interdepartmental coordination, where the Prosecutor’s Office, the Security Service of Ukraine, the National Police, the Ministry of Justice and representatives of public initiatives will work together to collect, preserve and verify evidence. This combination of legal, technological and ethical tools will allow Ukraine not only to increase the efficiency of investigations, but also to create its own model of documenting war crimes, which will become an example for other countries that seek to combine the rule of law, human rights and modern digital standards of evidence. Generalized statistical indicators allow us to conclude that currently less than 0.1% of all registered proceedings have reached the stage of trial. This indicates not only an overload of the system, but also the need to implement digital solutions to automate the accounting of evidence, the importance of high-quality analytical work and monitoring the effectiveness of processes. Thus, official statistics confirm the conclusions of the study on the need for technological and organizational renewal of criminal justice.

The results of the study confirm that the system of war crimes investigation in Ukraine is in a phase of profound transformation, caused by the need to combine national legal mechanisms with international standards of criminal justice. This conclusion is consistent with position Borovyk (2024) and Tymoshko (2024), who emphasize that the reform of procedural institutions should be based on the principle of complementarity with respect to the International Criminal Court, but at the same time highlight the problems of normative inconsistency and limited implementation of international norms into national legislation (Martyniuk et al., 2025). This principle implies that national courts have the primary jurisdiction to prosecute international crimes, while the International Criminal Court intervenes only when national authorities are unwilling or unable to conduct genuine investigations and prosecutions. Comparison with the results of other authors reveals certain contradictions. Thus, according to Hafetz (2024) and Glusman (2024), the main vector of the development of international justice regarding Ukraine is the creation of a special tribunal, while Ukrainian scholars and practitioners (Kovalchuk, 2024; Vyhivskyi et al., 2024) emphasize strengthening domestic institutional capacities and involving international structures only as coordination partners. Our study supports an intermediate position, according to which a combination of both approaches is optimal: the development of a national evidentiary system with the parallel use of international mechanisms in cases falling under the jurisdiction of the International Criminal Court.

The issue of digital evidence and the admissibility of OSINT materials remain particularly controversial. Wells (2025) and Popov et al. (2025) view digital forensics as key to investigative effectiveness, while Shevchuk et al. (2025) and Chlevickaitė (2025) warn about the risks of data distortion and the lack of unified authentication protocols. Our results confirm the latter’s position: although the use of open sources is an integral part of the evidentiary process, it requires regulatory consolidation of the principle of “chain of custody” and the creation of a database of digital evidence about war crimes. Some researchers (Rassamakhina, 2025; ZMINA, 2025) believe that the main factor in the effectiveness of investigations is the active participation of civil society, while others (Kosokhatko, 2025; Syvodіed, 2025) draw attention to the need for centralized management of the process and professional training of personnel. Our study demonstrates that the combination of these approaches – the interaction of state structures with volunteer and human rights initiatives – provides a balance between the efficiency of evidence collection and procedural legitimacy.

There are also discrepancies between the analytical assessments of international experts and the real state of the Ukrainian law enforcement system. While according to Europol (2025) and Eurojust (2025), the EU already has standardized mechanisms for exchanging evidence, Ukrainian practice, as noted by Peleschuk (2025) and Ochab (2025), demonstrates excessive workload of investigators and low percentage of proven cases. It means that regardless of the existence of technological solutions, the issue of personnel and organizational capacity is critical. Analyzing the received data, one may presume that the success of the war crimes investigation is directly determined by the extent to which digital technologies are integrated into criminal justice and the rate of alignment of the national law with international law. To prove this hypothesis, it is necessary to conduct additional empirical studies – in the first place, on the admissibility of digital evidence in a court of law and the formation of an ethical code of conduct when working with traumatic testimonies.

To investigate war crimes effectively, a complex of law and technological and humanitarian means should be used. Nevertheless, global political discourses play a crucial role in the perception of justice, which is why the perception of justice must have special attention in future scientific research, and both the legal and the communicative aspects of global justice are to be considered (Chu, 2024; Tran Sautedé et al., 2025).

Overall, the discussion reveals that, despite certain achievements of Ukraine toward the international integration in the sphere of the war crimes investigation, the lack of the unification of the evidentiary procedures, the enlargement of human resources potential, the establishment of the transparent system of digital forensics remains. To do this, one will require more interdisciplinary research that will integrate the legal, technological, and social aspects of contemporary justice.

The results of the study indicate that the system of investigating war crimes in Ukraine is undergoing significant institutional transformation. At the same time, its effectiveness remains limited due to the excessive workload of pre-trial investigation bodies, shortages of qualified personnel, and insufficient coordination between investigative institutions. Based on official statistical information published by the Office of the Prosecutor General of Ukraine (2025), it is possible to conclude that more than 187,000 war crimes were recorded in 20222025, however, in a few hundred cases, people were suspected, and less than fifty were sent to the court annually. It means that there is an unequal ratio between the magnitude of crimes and the national judicial system capacity.

The primary points where the efficacy of the pre-trial investigation of war crimes should be enhanced are:

1. Regulatory harmonization – revising the stipulations of the Criminal and Criminal Procedure Codes considering international requirements of criminal justice and the concept of complementarity with reference to the International Criminal Court.

Therefore, improving the effectiveness of war crimes investigations requires a coordinated approach that integrates legal reforms, technological modernization and the strengthening of institutional capacity. The proposed directions can become the basis for creating a national model of documenting and proving crimes, compatible with European and international standards of justice.