During the investigation of the circumstances of the hostilities in the area of the city of Ilovaisk, over 900 victims and witnesses have been interrogated. In particular, the leadership of the ATO and sector "B", as well as the commanders of the units subordinate to sector "B", were interrogated as witnesses regarding the circumstances of planning and conducting military operations in the area of the city of Ilovaisk in the Donetsk region, their encirclement by the RF Armed Forces and the irregular illegal armed formations under their control, as well as the exit from the enemy encirclement. Additionally, servicemen of the Armed Forces of Ukraine, the National Guard of Ukraine, and volunteer battalions were interrogated as witnesses and victims regarding the circumstances of the tasks to take control of the city of Ilovaisk in the Donetsk region, as well as the circumstances of the exit from encirclement along the routes provided by the Russian side, and the treacherous shooting of Ukrainian soldiers by the RF Armed Forces during the specified exit from encirclement.

From the ATO Headquarters, the General Staff of the Armed Forces of Ukraine, the Sectoral State Archive of the Ministry of Defense of Ukraine, the State Border Guard Service of Ukraine, the Main Intelligence Directorate of the Ministry of Defense of Ukraine, and other bodies involved in the fight against terrorism, over 1,670 combat documents with restricted access markings "For Official Use", "Secret", and "Top Secret" (including daily combat and reconnaissance reports, plans, orders, combat action logs, maps, satellite images, and others) have been seized, examined, and studied. The volume of materials in the criminal proceedings amounts to over 300 volumes, 70 of which have the relevant access restriction markings.

A comprehensive series of forensic medical, military commission, and other judicial examinations have been conducted.
For the completeness of the investigation and professional assessment of the issues of the application and interaction of forces and means involved in conducting the ATO in the Donetsk and Luhansk regions, the justification for management decisions made during the planning and conduct of military operations, including in August 2014 in the area of the city of Ilovaisk in the Donetsk region, with the involvement of 30 experts and specialists from relevant military fields of knowledge, two comprehensive commission military judicial examinations have been conducted.

According to the results of the investigation and the conclusions of the judicial examinations, the following key factors have been established against the backdrop of the invasion of RF Armed Forces units and the subsequent occupation of certain areas of the Donetsk and Luhansk regions:
1. Low level of combat readiness and combat capability of the Armed Forces of Ukraine.
2. Numerous facts of desertion, unauthorized abandonment of military service locations, and non-compliance with orders from superiors among the personnel of the Ukrainian army during that period.
3. Certain mistakes by the ATO leadership during the planning and conduct of military operations, which are not directly causally related to the occurrence of severe consequences – the death and injury of Ukrainian soldiers and the loss of weapons and military equipment.
According to the experts' conclusions and a range of other obtained evidence, the only factor that is directly causally related to the Ilovaisk tragedy is the military aggression of the Armed Forces of the Russian Federation in the form of direct invasion of the territory of Ukraine and the subsequent commission of war crimes by the aggressor country’s military.

As a result of the investigation and based on the collected evidence, 4 generals from the command staff of the Armed Forces of the Russian Federation have been brought to criminal responsibility, who directly organized the invasion of regular Russian troops on 24.08.2014 into the territory of Ukraine, conducted hostilities against ATO forces, and further treacherously killed Ukrainian servicemen during the exit from encirclement.
Additionally, in order to ensure the accountability of the Russian leadership at the international level regarding the events near the city of Ilovaisk, the Department has prepared 2 analytical submissions to the Office of the Prosecutor of the ICC:
- regarding the facts of treacherous murder and wounding of individuals on the territory of the Donetsk region (events in the area of the city of Ilovaisk on 29.08.2014, events in the area of the Donetsk International Airport on 19-20.01.2015);
- regarding the facts of extrajudicial executions (murders) of Ukrainian Armed Forces servicemen by representatives of the armed group "Cossack Union 'Oblast of the Don Cossacks'" during the battles of 2014-2015. Among the victims were also Ukrainian servicemen captured during hostilities in the area of the city of Ilovaisk in the Donetsk region.

At the same time, the pre-trial investigation in the criminal proceedings on this fact is significantly complicated due to objective reasons – law enforcement officers currently do not have access to the territories where the war crimes were directly committed, which makes it impossible to conduct the full range of necessary investigative actions, find and seize physical evidence, appoint relevant examinations, etc.
At present, it is not possible to declare the suspects in the commission of war crimes wanted internationally, as Interpol, in accordance with Article 3 of the Statute, does not issue wanted notices for individuals suspected of committing war and political crimes.

The Russian Federation directly refuses to comply with requests for international legal assistance in this case and does not serve procedural documents to the suspects, does not conduct interrogations of witnesses and eyewitnesses, and does not issue documents containing traces of crimes.
Despite this, the investigation continues, and investigators and prosecutors are taking all measures provided for by the Criminal Procedure Code of Ukraine to establish and hold accountable all individuals involved in the commission of the specified crimes.