Assessment Findings

Considering that for partial destruction of glazing the value of $\Delta P$ must be no less than 0.015 atm and no more than 0.02 atm, and solving equation (1) for G, we obtain an explosive charge mass in TNT equivalent of no less than 800 kg and no more than 1850 kg. It is not possible to provide a more accurate assessment due to the expert's lack of information regarding the dimensions of the glass, the methods of their mounting in the frames, and the strength of the frames themselves.

The nature of the destruction and damage to the houses, as well as other surrounding objects, indicates that an explosion of a high explosive occurred in the form of detonation. To initiate detonation in a high-explosive charge, an industrially or craft-manufactured means of initiation (MI) is required—an electric detonator or a blasting cap; therefore, the design of the explosive device included industrially or craft-manufactured electric detonator(s) or blasting cap(s).

Analysis of expert practice, as well as the results of field experiments specially conducted at the All-Russian Federal Nuclear Center (Sarov) with various masses of high-explosive charges, show that with charge masses exceeding 5 kg, it is not possible to find any informative remains of the actuating mechanism of the explosive device (means of initiation in the form of shell fragments and end wire fragments, electric current sources, connecting wires, time delays, and electronic boards), its packaging (container), or camouflage suitable for diagnostic studies. During the explosion of an explosive charge, the listed items fragment into minute particles, which are projected at high speed and further shattered upon impact with obstacles. This is explained by the extremely high explosion parameters (pressure, temperature, speed of explosion products) of large masses of explosives. Based on the foregoing, it is not possible to determine the specific design and method of activating the explosive device.

CONCLUSIONS

Regarding Question 1

The destruction and damage to the objects were formed as a result of the action of an explosion.
Expert T.V. Vinogradova

Regarding Question 2

The mass of the detonated charge was 800–1850 kg in TNT equivalent.
Expert T.V. Vinogradova

Regarding Question 3

A mixed explosive was used as the explosive charge, which included TNT, hexogen, and, most likely, aluminum; in addition, ammonium nitrate could have been included, or a combination of the substances listed above and explosives based on them.
Expert K.N. Stovbur

Regarding Question 4

It is not possible to establish the specific brand of the detonated explosive from trace amounts. For this reason, it is not possible to determine the field of application of the mixed explosive mentioned above or the explosives that were part of the combined charge.
Expert K.N. Stovbur

Regarding Question 5

The explosive charge was located either in the immediate vicinity of the GAZ-53 and PAZ-3205 vehicles or inside them, in front of the 4th entrance of building No. 35 on Oktyabrskoye Shosse.
The design of the explosive device, in addition to the explosive charge, included industrially or craft-manufactured electric detonator(s) or blasting cap(s). It is not possible to determine the specific design of the device and the method of its activation.
Expert T.V. Vinogradova

reg. No. 16/3/4/1954