A characteristic sign of a point-blank shot is. Signs of a shot at close range
In entrance gunshot wound when fired with a loose focus on the skin, a significant number of additional factors of the shot are detected; with a tight stop, they are found mainly in the wound channel, over a considerable length of it. With both variants of a point-blank shot at areas of the body where the bone is close, bone fragments and scraps of muscle fibers can be seen in the preparations of the entrance wound.
They are appear here due to the fact that the column of compressed air and powder gases, producing significant damage, causes the movement of damaged tissues in the direction of the shot. Scraps of muscle fibers can be observed in the entrance wound not only when fired at point-blank range, but also from various distances due to the special ballistic properties of the high-energy wounding projectile.
This must be kept in mind so as not to to accept an entrance wound for an exit wound, if there are no other signs of an entrance wound.
exit wound. With a long shot distance, as well as with a long wound channel, regardless of the shot distance, the morphology of the edges of the exit bullet wound is not much different from wounds such as lacerations or stab wounds caused from the inside by bone fragments. The edges and surface of the skin around the wound do not have sediment and additional factors of the shot. The edges of the wound are raised, in some places turned outward, the tissue of the skin itself protrudes from the wound above the level of the skin, and sometimes subcutaneous fatty tissue and fragments of muscles.
Change skin along the edges of the wound, simulating a belt of sedimentation, can be observed if the body at the exit site of the bullet was in close contact with some blunt solid object. Morphologically, such "settlement" is similar to the settling around the entrance wound (see above).
At shot at point-blank range or from a very close distance into the area of the body where a short wound channel is formed, in it, near the exit wound, one can detect metal particles, soot, single powder grains, graphite particles, and if the body area was covered with clothing, then fibers of clothing fabrics. Metal particles in the area of the exit wound are sometimes found even with a large length of the wound channel, when the bullet was damaged by passing through the bone.
In this case, bone fragments are also found near the exit wound.
It must be emphasized that in definition type of weapons and ammunition used, microscopic examination results are of limited value. They come down to the definition of smokeless or black powder by the type of grains, and in some cases, the grade of smokeless powder. So, viscose powder is determined by its characteristic concentric striation.
The study of the wound channel begins from the edge of its wall. It appears to be uneven, the tissue here is crushed, torn, split, in some places turned into amorphous areas. In structureless tissue, erythrocytes are well defined. Occasionally, fragments of blood vessels, adipose tissue, and muscle fibers are found among them. Violation of the integrity of the tissue should be determined over several consecutive fields of view of low magnification of the microscope.
An important issue resolved by the forensic medical examination is the determination of the distance of the shot. In forensic medicine, three shot distances are distinguished:
- point-blank shot;
- shot at close range;
- Shot at close range.
Point-blank shot
- when the muzzle end of the weapon (barrel or compensator) is in direct contact with clothing or the skin of the body. In this case, the muzzle end can be pressed against the body very strongly or only slightly touch it, be directed perpendicularly or at a different angle. With different contact options, the nature of the damage will be different.
Signs that characterize a point-blank shot:
1) soot and powders in the circumference of the wound (loose, leaky stop), bullet channel. When fired from an angled weapon, gases are partially directed outside the inlet, and soot particles cover the skin area located from the side of the open angle. By the location of the soot, you can determine the position of the weapon at the time of the shot;
2) rupture of the edges of the inlet is a variable sign, it depends on the caliber of the weapon, the size of the powder charge. The so-called cruciform ruptures occur more easily where the bone is close under the skin;
3) the imprint of the muzzle (braking device) - "stamp mark" - an absolute sign, but inconsistent;
4) pronounced chemical effect of gases, determined in the wound channel3.
Shot at close range
- this is a shot within the action of additional factors (traces) of the shot. Additional traces of a shot can be found on average up to 1 m. The ratio of individual components, such as soot and powder, allows you to more accurately determine the distance of the shot.
Shot at close range
shot outside the range of additional shot marks. If, within a close shot, the ratio of the distribution of soot, powders, and the action of gases allows one to navigate quite accurately in the distance of a shot in centimeters, then when shooting from a close distance, only in rare cases can an expert talk about a certain distance of a shot (for example, in the case of a blind wound ). Sometimes the lack of additional traces can be caused by a shot through an obstacle, which can mislead the investigator and the expert as to the distance of the shot.
In some cases, an expert may assist the investigation in determining the type (system) of the weapon used. The type of weapon can be determined by the nature of the damage, by the muzzle imprint (“punching mark”), by the penetrating ability of the bullet, by the bullet, by the size of the gunshot wound and bone damage, by the shape and size of the powder grains, by the specific location of the shot soot deposits.
If there are several gunshot wounds found on the corpse, the expert resolves the issue of whether these wounds were caused by one shot or several. The number of wounds can be more than the number of bullets, and vice versa. The first possibility usually occurs when a bullet, having pierced one part of the body, then penetrates into others.
The location of the wounds with the corresponding movements of the limbs along the same line makes it possible to identify the possibility of their infliction by one bullet. Several wounds from one bullet can also be observed in cases where the bullet, before penetrating the body, is torn apart, which often occurs when shot from a sawed-off shot, as well as with ricochets and defeats through an obstacle.
This is often recognized by the peculiar shape of the entrance holes, which do not usually have a rounded contour, as well as by the detection of individual parts of the bullet in the tissues. Another possibility is the detection of several bullets at one entrance hole. This is observed when a bullet breaks inside the body when fired from a sawn-off shotgun.
When multiple gunshot wounds caused by several shots are found, it is advisable to examine clothing or skin areas with inlets in ultraviolet rays in order to detect gun grease. When shot from a cleaned and lubricated channel in the area of the inlet, more weapon grease is found from the first shot than from subsequent ones.
In some cases, a forensic medical examination reveals signs that are characteristic of causing damage to one's own or an outside hand. Forensic practice shows that injuries to certain and most dangerous areas of the body (right temporal region, heart, mouth), observed when shot at close range and from a distance of several centimeters, most often occur with the action of one's own hand.
A reliable sign of the action of one's own hand is the special additional devices installed during the inspection of the scene of the incident: for a shot from a hunting weapon, a rope, stick or finger of the lower limb is adapted, from which shoes are first removed). Under the action of one's own hand on the hand in which the weapon was located, abrasions, blood splashes, particles of brain matter, the smallest bone fragments, as well as traces of soot are revealed.
1. Traces of action of powder gases. Hot powder gases, escaping at high speed after the projectile from the bore of the weapon, when fired at close range and at very short distances, have a mechanical and thermal effect.
The mechanical ones include: punching and rupture, and the temperature ones include scorching, charring and burns. In some cases, a sign of a point-blank shot is the formation of a so-called stamp-imprint.
The penetrating effect of powder gases is expressed in damage to the material of the object outside the area of impact of the projectile itself. But the possibility of penetration depends to a large extent on the properties of the material of the object, primarily its elasticity and mechanical strength.
The same properties affect the shape and size of the damage.
So, in materials with great elasticity, for example, sole rubber, rubberized fabric, even when fired at close range and, moreover, from such a strong combat weapon as a 7.62-mm domestic rifle of the 1891/30 model, only a pinhole is formed with torn edge.
In less elastic materials (cloth and cotton fabrics), when firing from the same rifle from a distance of up to 3 cm from the stop, a tissue defect is formed, the dimensions of which exceed the diameter of the bullet by two to three times.
The penetrating effect of gases on the skin, protected by clothing, when firing from the specified rifle is observed at the following distances of the shot.
When fired at close range, the inlet in the skin has a size that is much larger than the diameter of the bullet.
When fired from a distance of 1 cm, the inlet in the skin is smaller in size than when fired at close range, and sometimes approaches the diameter of a bullet.
The penetrating effect of gases on the skin ceases from a distance of 3 cm.
The explosive effect of powder gases is manifested in the tearing of the edges of the inlet. Depending on the number of tears and their location, the inlets are named - linear (slit-like), star-shaped (radiated) and cruciform.
The shape and size of damage depend on the distance of the shot, the caliber and system of the weapon, the strength and elasticity of the material of the object, and in clothing, for example, on the presence of seams, its moisture content, the tension of the material, the nature of the interlacing of threads, etc.
This relationship can be traced from the data below.
When shooting at cotton fabric - madapolam - (given by V.I. Prozorovsky), tearing of the edges of the entrance bullet hole was observed:
a) from a stop to 1.5 cm - when firing from a 7.62 mm Tokarev pistol (TT) and a 7.65 mm Walter pistol;
b) from a stop to 3 cm - when firing from a 7.63 mm Mauser pistol, model 1908 and a 9 mm Bor pistol
hardt-Luger (Parabellum);
c) from a stop to 10 cm - when firing from a 7.62 mm domestic rifle mod. 1891/30
It was noted that when firing from the same weapon within the above distances, with the exception of a shot at close range, tears in the edges of the entrance bullet holes were not always formed.
There were no tears in the fabrics of clothing when firing at point-blank range from small-caliber pistols and revolvers.
When shooting at clothing fabrics and shoe materials from a 7.62-mm domestic rifle mod. 1891/30 (according to I. F. Ogarkov) the following phenomena occur:
a) in cotton fabrics, the edges of the inlet were torn at a distance from the stop up to 3 cm; from a distance of 5 cm or more, they were torn only in some cases; from a distance of 10 cm, the explosive action ceased;
b) in the cloth fabrics, tears were formed when fired from the stop up to 5 cm;
c) in leather shoes from the stop to 3 cm;
d) in the rubber sole of the shoe from the stop to 3 cm; there was no tissue defect.
When shooting at cotton and woolen fabrics, with factory-made cartridges from smooth-bore shotguns-12, 16, 20 calibers (according to Ya.
Tears of the edges of the inlet during shots into the skin (according to M. I. Avdeev) were observed in the following cases:
a) at point-blank range from a 7.62 mm Nagant revolver model 1895, a 7.62 mm Tokarev pistol (TT), a 7-65 mm Browning pistol model 1910, an 11.43 mm Colt pistol model 1911 .
b) When firing from a stop to 5-9 cm from a 7.62 mm domestic rifle mod. 1891/30
All the above data are indicative for determining the distance of the shot, since the occurrence of tears also depends on a number of other factors, in particular, the condition of the weapon, the brand of ammunition, etc.
In the presence of weapons and ammunition, which, according to the investigation, the shot was fired, it is necessary to clarify the specified data in relation to this weapon and ammunition by means of experimental shots.
It should be borne in mind that tears in the edges of the bullet hole do not always indicate that this hole is an inlet and is formed by the mechanical action of powder gases. Similar damage is observed at the edges of the exit holes. They occur when fired from a weapon of strong combat (rifle, carbine, etc.) and, as a rule, when the bones of the skeleton are damaged. The mass of bone fragments knocked out of the perforated bone, moving along with the bullet, first causes a rupture of the skin, and then the fabrics of clothing. Sometimes the length of individual rays of tears of the outlet exceeds the length of the rays of the inlet. In these cases, the inlet is determined by the presence of traces of a close shot (subsidence, soot, powders).
When describing a gunshot injury in the protocol, it is necessary to note:
a) the shape of the damage and the nature of the edges of the damage;
b) the size of the damage. When describing a defect of a round shape
it is characterized by its diameter. With an oval-shaped defect, the major and minor axes of the oval are measured in mutually perpendicular directions. In this case, the torn edges of the fabric around the defect are included in the determined dimensions, that is, the measurement is made between opposite points of the defect lying on
the base of the flared edge. Separately, each ray of tear is measured with an indication of its direction.
Formation of a stamp-imprint (stamps). When fired point-blank or almost point-blank, that is, with a small gap between the target and the muzzle of the weapon, sometimes an imprint of the muzzle end or some part of the weapon (ramrod, namushnik, casing) located in the plane of the muzzle is formed on the surface of the affected object weapons. This imprint is observed both on the skin and on the fabrics of clothing. According to the configuration of the imprint, in some cases it is possible to determine the caliber and type of weapon, and sometimes the number of barrels of hunting weapons.
Temperature effect of powder gases. Gases, having a high temperature, affect the fabrics of clothing, the skin of the body, causing scorching, charring, burns and, in some cases, ignition.
Singed. White fabrics made from plant fibers, exposed to high-temperature powder gases, acquire a color from yellow to dark brown; while the structure of the fibers that make up the threads of the fabric remains unchanged. In wool materials, depending on the degree of shedding, in addition to color changes, there is also a structural change in the material of the hairs. Structural change is expressed in the appearance of air bubbles both in the medulla and in the thickness of the hair. With intense burning, the number and volume of air bubbles increase, as a result of which individual sections of the hairs swell unevenly (swell), and the hairs bend or twist. Light hairs become dark yellow to dark brown in color. Traces of light delamination, marked by yellowing of the hairs, are difficult to recognize by visual examination, as they are covered with soot. Signs of scorching on woolen materials that have a color that differs little from the color of scorched hairs are detected using a magnifying glass or microscope.
Charring of clothing material is the result of a slow process - smoldering or a fast process - ignition. The charred edges of the entrance gunshot holes are very fragile and crumble from a light touch, forming an irregularly shaped hole. Depending on the nature of the fibers that make up the fabric, the latter in a charred state has a color from dark brown to black. Areas of charred woolen clothing give off the smell of burnt horn.
We give approximate data related to the temperature effect of powder gases on clothing materials.
When firing with black powder, shots from revolvers of old systems and a 7.62-mm Nagan revolver of the 1895 model in the range from stop to 10-15 cm cause the following phenomena: burns of the skin, inflammation, smoldering and browning of clothing fabric (according to M. And . Avdeeva). Shots from a hunting smooth-bore shotgun in the range from stop to 50 cm quite often cause burnt edges of the inlet on clothing (according to Ya-S. Smusin).
When firing with smokeless powder, shots from a 7.62-mm Tokarev pistol (TT) in the range from stop to 8-10 cm sometimes cause singing, which is expressed in browning of the clothing material around the inlet (according to A. P. Belov and S. D. Kustanovich).
Shots from rifle sawn-off shotguns in the range from stop to 30 cm sometimes cause scorching of clothing fabrics (according to B. R. Kirichinsky).
Shots - from a hunting smooth-bore shotgun at close range sometimes cause burnt edges of the inlet, and in the range from stop to 25 cm, only slight singing is observed (according to Ya-S. Smusin).
Not every shot at the above intervals from the same weapon with ammunition loaded with smokeless powder causes the fibers of clothing around the inlet to be scorched. Singing is noted only with a sharp increase in the pressure of powder gases at the muzzle of the weapon barrel.
The reasons that give rise to muzzle pressure, which is many times higher than the norm, are diverse and difficult to take into account. Such reasons include bore wear, shortening of the barrel (cutoff), discrepancy between the calibers of the bullet and the weapon (the diameter of the bullet is less than the diameter of the bore in the margins), reduced sensitivity of the primer, the moisture content of gunpowder, etc.
2. Traces of soot. Soot is a small solid and liquid particles formed in the bore of a weapon during the explosive decomposition of gunpowder and percussion composition. Soot mainly consists of metals and their compounds.
Powder gases and the soot suspended in them escape from the bore not in a continuous jet, having a cylindrical or conical shape, but in the form of a jet consisting of a number of successive uneven portions (condensations) of gas.
The flight range of soot particles depends on the type, system, caliber of weapons, grade and amount of powder charge. Soot, meeting with an obstacle, settles around the bullet hole in a black-gray spot of a rounded shape, and sometimes in the form of two spots of a rounded shape, located at some distance from each other. Such isolated termination spots occur when a strong combat weapon (rifle, carbine, etc.) is used, either when fired point-blank or almost point-blank, or when the weapon is not firmly fixed in the hands at the time of the shot.
The spot surrounding the bullet hole is called the main (primary) field of soot deposition. A spot located away from the bullet hole is an additional (secondary) field of soot deposition. An additional field of soot deposition occurs after the main one at the moment of recoil of the weapon, that is, after the barrel moves quickly a certain distance to the side. If the displacement of the trunk is small, the secondary field of termination remains within the primary field, and the overlap of the two fields is more pronounced.
Cases have been registered when, when fired at close range, only an additional (secondary) field of soot deposition is found on the outer surface of the tissue, which is located away from the bullet hole. In these cases, the bulk of the soot is on the opposite side of the outer clothing, on the fabrics of the lower clothing and in the bullet channel.
Depending on the distance of the shot, the type and amount of gunpowder, the type, system and caliber of the weapon, the placement of soot particles within the boundaries of the spot is uniform or uneven.
The main types of uneven pumping are ring-shaped, beam-shaped and spotty.
Ring-shaped infilling is characterized by the alternation of dark and light zones, that is, the presence of a number of concentric zones around the bullet hole, which differ from each other in width and the amount of soot per square centimeter of area. Radiation infiltration differs from annular infiltration by the presence of thickenings radiating from the central zone in the form of rays. Spotty sooting differs from annular soot by the presence of soot thickenings in the form of spots of various shapes, which are located within the total area of soot deposition.
The deposition of soot around the bullet hole indicates a close shot and that this hole is an inlet.
Detection of ring-shaped, ray-shaped and spotted inkling by ordinary examination is possible only on light-colored clothing fabrics. Detection of soot on dark or contaminated surfaces presents significant difficulties.
Soot, meeting with the fabric of clothing or skin, not only settles around the bullet hole, but also penetrates into the thickness of the material, being located between the fibers of the fabric. The depth of penetration of soot particles, for the same type of weapon, depends on the distance of the shot and the density of the tissue encountered. As the distance of the shot increases, the depth of soot penetration decreases, and from a certain distance, soot particles settle only on the surface of the fabric.
We provide indicative information for determining the distance of a shot based on the signs of deposition of soot of smokeless powder.
The 7.62 mm Nagant revolver of the 1895 model, when fired at white material from distances of up to 15 cm, gives a clearly visible filling; from 15 to 20 cm - slightly noticeable; over 20 cm, there is no infilling (according to M. I. Avdeev and N. V. Popov).
The 7.62-mm Tokarev pistol (TT) when fired at a white material (coarse calico) from a distance of less than 45 cm gives a clearly visible blocking (according to I. V. Skopin).
The 7.63 mm Mauser pistol, when fired into white material, gives a noticeable smoky eye from distances less than 30 cm.
The 7.65 mm Walther pistol and the 9 mm Borchardt-Luger pistol cause visible under normal conditions blotting of white material when fired from distances less than 25 cm (according to V. I. Prozorovsky).
The 7.65 mm Browning pistol causes visible blotting of white material when fired from distances of less than 15-20 cm (according to N.V. Popov).
7.62 mm domestic rifle - model 1891/30 causes a clearly visible infiltration of white material when shot from distances less than 30 cm. On materials of gray and dark gray, soot is clearly visible when shots are fired from the stop to 5 cm. Infiltration is a blackish rounded spot with a diameter of 3 cm to 8 5 cm
When shot from a distance of 7-15 cm, a faintly noticeable spot of a rounded shape without visible borders along the periphery is observed. When shot from distances exceeding 15 cm, soot is not noticeable.
On darker materials than the above, soot is detected by ordinary inspection when shots are fired from the stop to 5-10 cm.
On the inner layers of clothing, soot is observed when shots are fired from a distance of up to 5-7 cm from the stop.
The deposition of soot on the skin, protected by clothing or leather shoes, is observed constantly with shots from a stop up to 3 cm and inconsistently - from 5 cm to 15 cm. When shots from distances exceeding 20-25 cm, soot is not noticeable.
The belt of soot, around the inlet in the skin, has a width of 1.5 mm to 4 mm (according to I. F. Ogarkov).
When determining the distance of a shot by the nature of pumping, it must be borne in mind that the first shot from a launched weapon (the bore is covered with dirt and rust) can create a false impression of a close shot, since particles of dirt and rust fly a much greater distance than powder soot.
Determining the distance from which the shot was fired becomes essential in the investigation of self-harm, cases of misuse of firearms, exceeding the limits of necessary defense, in the investigation of murders disguised by the appearance of an accident, suicide, etc.
In criminology there are:
1. Point-blank shot(the muzzle of the weapon is in full or partial contact with the damaged object) A characteristic sign of a point-blank shot is muzzle imprint weapons on the barrier ( stamping mark). Together with the muzzle, other details that are in the same plane are often imprinted: namushnik, casing, ramrod. The stamp mark allows you to judge the type and caliber of weapons.
2. Shot at close range(on the barrier act not only a bullet, but also powder gases escaping from the barrel, soot and unburned powders) Hot powder gases, escaping at high speed from the bore, have high kinetic energy, mechanical and thermal effects. The nature and severity of this action is determined by the composition and state of the powder charge of smoky and smokeless powder, the length of the weapon barrel, the type of surface being damaged, and other conditions.
On distance several (1-3) centimeters gunpowder gases save form channel trunk firearms and have a barrier penetrating action. In this case, a tissue defect is formed, the dimensions of which can exceed the dimensions of the bullet by several times and will be the larger, the less the elasticity of the damaged barrier.
On the longer distances powder gases, meeting air resistance, acquire mushroom shape and render to the barrier breaking action, expressed in tears of the edges of the inlet. The shape of this tear can be linear (slotted), cruciform or star-shaped. The size of the tear depends on the distance of the shot and the type of damaged barrier.
signs shot at close range:
- Traces of action of powder gases
Penetrating action
Breaking action
Formation of a stamp mark
Temperature action
singeing
Charring
Ignition of the barrier
- Traces of soot, which is formed as a result of the decomposition of powder and primer charges. The composition of the soot of the shot also includes metal particles from the bore and bullet shell. The soot of the shot is deposited on the barrier around the bullet hole in the form rounded black-and-gray spots.
When fired from modern designs firearms, the soot of a shot is deposited on an obstacle in the distance no further than 30-50 cm.
When shooting at multilayer barriers e.g. clothing, shot soot can be deposited around the inlet and when long range shooting(up to 900 m and more). (up to 25 cm).
Infiltrated into the barrier powder grains and particles of gun grease.
Most of powder grains does not fly further 80 cm.
Particles lubricants thrown out on 45 - 150 cm.
When shot at close range on the surface of a damaged object in some cases
no traces of soot are found and introduced powders or these traces are weakly expressed. This is explained by the fact that the bulk of the powder gases rush into the wound channel, on the walls of which these additional traces of the shot are deposited.
3. Shot from a distance(with a long-range shot, the effect of the indicated additional factors of a shot on an obstacle ceases)
Establishing the place from where the shot was fired.
Possibly with:
Bullet channels in two objects located at some distance from each other
In one object through, and in the other blind bullet channel
There are some things to consider, for example:
- invariance of the position of damaged objects after the shot
Possibility ricochet bullets on the segment between two objects
- bullet deformation when passing an obstacle, because center of gravity may change, and the angle of entry will be different from the angle of passage
- material heterogeneity barriers
- path curvature bullet flight
The definition of the line of flight of a bullet is made using:
- sightings:
- with a paper tube inserted into the holes in the two glasses of the window frame (if the holes are round);
With help camera;
By using threads;
- Calculation-graphical method(for this purpose, big plans scenes of the incident with the exact designation on them of the damage caused by the bullet on the furnishings, which are connected by a straight line. The horizontal projection of the plan shows the location of the bullet's flight line relative to the furnishings (top view), the vertical projection shows the upward or downward direction of the bullet's flight and its level (side view))
- At the location of spent wad shells and gaskets.
The issues of the theory of forensic identification are of particular importance for expert forensic research, but they are no less important in the practical activities of the investigative and judicial bodies, i.e. have general theoretical significance.
Forensic Identification Theory (FIT)- the doctrine of the general principles of identification (establishment) of various material objects by their reflections in order to obtain forensic evidence.
According to Kornoukhov: identification theory (along with recognition and reconstruction theories) refers to empirical-theoretical level of knowledge and describes the process of identifying objects (people, things) according to a mental image and materially fixed reflections (traces) in order to justify the fact of identity, because it allows you to prove the spatial and (or) temporal connection of a single object (person, thing) with the crime event and ( or) the place where the crime was committed.
Reflection forms(3) (Kornoukhov):
1. External building,
2.Sustainable mode of action,
3.Sustainable energy performance.
Forms process identification (2):
1. Expert
2. Investigative (examination and identification).
Display Forms(determine the specifics of forms of identification):
1. Material-fixed display (traces of hands, feet, vehicles, implements and tools, typewritten and handwritten texts, etc.).
Give them the opportunity to study technical methods, applying methods and means of working with material evidence.
2. Display of identified objects in human memory(a sensory-concrete representation preserved in the memory of a person who gives a description of the signs of the appearance of a person or some thing).
They do not represent the possibility of studying by technical methods and require
other research methods(interrogation, identification, etc.).
Identity- the coincidence of a set of features that belong and are inherent in only one single object.
similarity- the ratio of two or more objects, or the coincidence of a number of features of several objects.
The essence of forensic identification consists in establishing the identity of this particular object by the totality of its general and particular identification features. And the whole process of identification, carried out with the help of a comparative study of the signs of objects, their reflections, in forensics is called forensic identification. (Kornoukhov)
Principles of forensic identification.
1. Division of objects into identifiable and identifying.
To the number identifiable objects include persons, animals, things;
(For example: a hacking tool seized from a suspect)
To the number identifying - display these objects (identifiable). (For example, traces of a hacking tool found at the crime scene and traces obtained as a result of the experiment).
In the broad sense of the word, gunshot wounds mean damage from all types of firearms, from explosions of ammunition (cartridges, artillery shells, mines, grenades, explosives) and their parts (primers, fuses, detonators). The frequency of gunshot injuries depends on the number of firearms that certain population groups have in circulation.
The nature of gunshot wounds depends on many reasons, and primarily on the characteristics of weapons and ammunition.
Firearms and ammunition.
Firearms are divided into artillery and small arms. Small arms are divided into group (machine guns, mortars) and hand (individual). The vast majority of gunshot wounds encountered in forensic practice in peacetime are inflicted from hand weapons. Hand firearms are subdivided into combat (combat rifles, carbines, submachine guns, pistols and revolvers), sporting (small-caliber rifles, pistols and revolvers), hunting (single-barreled, double-barreled), special (flare pistols, starting pistols), defective (trimmings), homemade (self-propelled guns).
Combat firearms are rifled.
Cartridges consist of a bullet, a cartridge case containing gunpowder, and an explosive primer. Bullets are lead (currently in hunting and sporting weapons), shell (shells made of copper, cupronickel, lead core), special-purpose bullets (tracer, armor-piercing, explosive, incendiary), home-made. Distinguish gunpowder smokeless and smoky. When ignited, black powder produces a lot of smoke, soot, and flames.
At the time of the shot, under the action of powder gases formed from the ignition of gunpowder, a projectile (bullet or shot) is ejected from the bore of the weapon. In this case, the bullet, which receives translational and rotational motion around its axis, sets in motion a column of air located in the bore in front of the bullet. The resulting compressed air, when fired from a very close range, acts on the barrier first and can cause patchy tears in clothing, skin, into which the bullet and gases that follow the bullet penetrate.
When fired, in addition to the bullet, the following fly out of the barrel bore:
1) a flame that is formed from the contact of hot gases with oxygen in the air;
2) gases;
3) soot;
4) unburned or partially burnt powders;
5) metal particles that are erased from the bore, from a bullet, from a cartridge case, and also formed from the decomposition of primer products;
6) droplets of gun grease, if the weapon was greased.
In the case of a shot at close range, these additional factors of the shot act on the obstacle and are detected during the study.
Upon contact with the human body, the enormous pressure of the bullet in the form of a shock wave is instantly transferred to the surrounding tissues, causing them to vibrate. Following the bullet moving in the tissues, a pulsating area, which is much larger in volume than the bullet, is formed, which transmits oscillatory movements to neighboring organs and tissues. For example, when a bullet passes through the soft tissues of the thigh near the femur, its fractures are often observed. Hence, the action of a bullet on the human body is composed of direct action (impact) and the impact of energy transmitted from the side (side action).
When a projectile hits organs containing a liquid or semi-liquid medium, the hydrodynamic effect of the bullet is observed. The latter lies in the fact that these organs (filled bladder, heart in diastole, head) are often torn during gunshot wounds. The hydrodynamic effect of the projectile is due to the fact that the liquid and semi-liquid (brain) medium is practically incompressible, transmits the energy of the bullet in all directions with the same force, contributing to multiple ruptures.
During the forensic medical examination of gunshot injuries, a number of questions arise. The main ones include the following:
1. Is this damage gunshot?
2. What wound is the input and what is the output?
3. From what distance was the shot fired?
4. What is the direction of the bullet channel in relation to the body of a standing person?
5. What weapon was fired from?
Other questions that often arise, arising from the essence of a particular criminal case. For example, the medical examiner is sometimes asked to determine:
1. The number of gunshot injuries and their sequence.
2. The position of the deceased and the shooter at the time of the shot.
3. Whether the victim moved after the injury.
Diagnosis of a gunshot wound
inlet and outlet.
Gunshot wounds can be through and blind. With a penetrating wound, the bullet passes through the human body and leaves it, while with a blind wound, the bullet lingers in the body due to its insufficient penetrating ability. Sometimes there are tangential wounds, when the bullet only touches the body, causing superficial wounds to soft tissues or forming only an abrasion.
Forensic medical diagnosis of each of the described types of gunshot injuries has its own characteristics. At the same time, the vast majority of gunshot wounds (through, blind) are characterized by certain diagnostic features that make it possible to distinguish a gunshot wound from other wounds, and primarily from stab wounds. During an external examination of a corpse, the diagnosis of gunshot wounds is based primarily on sectional signs of the inlet.
A bullet with sufficient kinetic energy has a penetrating effect, first pulling the skin in the form of a cone, and then knocking out part of it and taking it with it into the wound channel. Thus, the bullet acts as a piercer, punching out the skin in the entry area. This phenomenon was subsequently called tissue defect or "minus tissue".
A practically described sign is determined when the edges of the wound approach each other. If the edges of the wound do not come together, do not close the wound channel, then we can talk about a tissue defect. If the edges come together due to skin tension, then folds form in the corners of the wound, which also indicates a tissue defect.
The shape of the inlet depends on a number of conditions. If the bullet hit the body at a right angle, then the entrance hole will usually be round. If the bullet enters the body at a different angle, then the inlet becomes oval.
When penetrating the body, the bullet wipes the particles that are on it along the edges of the inlet (traces of grease, soot, powder deposits, rust), forming a so-called wiping belt or pollution belt in the inlet circumference. The latter is a grayish ring, under which a second belt is found - the sedimentation belt. Due to the extensibility of the skin, its defect in the region of the inlet is usually 1-2 mm smaller than the diameter of the bullet.
Immediately after the injury, the belt of sedimentation is a ring of pinkish-red color, which dries up and becomes dark brown. The width of the belt is equal to 1-2 mm, its shape depends on the angle of entry of the bullet. When wounded at a right angle, the belt of precipitation will be uniform around the entire circumference; when a bullet enters at an acute angle, the belt becomes in the form of a semi-oval.
When a bullet passes through clothing, the belts of contamination and metallization on the skin may be absent. In such cases, these belts can be found when examining clothes.
In contrast to the inlet, a tissue defect is usually not observed in the outlet, since the wedge-shaped action of the bullet is manifested here. The bullet in the area of the exit hole pulls the skin in front of itself in the form of a cone and breaks through it at its top. Therefore, the edges of even a large exit wound approach each other when approached.
As for the wiping belt (contamination) and traces of gun grease, they can only be detected in the region of the inlet and are not observed in the circumference of the outlet.
The outlet hole is larger than the inlet hole. The edges of the inlet are screwed inward, and the edges of the outlet appear to be somewhat turned outward. However, the latter signs are inconsistent. Therefore, in some cases it is very difficult to distinguish the inlet from the outlet by the size, shape and nature of the edges. Occasionally, multiple exits will be found with one inlet, which may depend on the deformation of the bullet and its separation into separate fragments, which will act as independent projectiles, giving separate exits. This sign is constant when hiding the traces of the crime, when the criminal makes notches on the tip of the bullet.
Determination of shot distance.
In forensic medicine and criminology, three shot distances are distinguished:
1. Point-blank shot.
2. Shot at close range
3. Shot from a long (not close) distance.
SHOT POINT SHOT.
When fired at close range, the muzzle of the weapon rests against the body. In this case, the weapon can be tightly pressed against the body (full hermetic stop), not tightly touch the body only with the edge of the muzzle when the weapon is attached to the body at an angle (side stop).
With full support, the wound channel is, as it were, a continuation of the bore, therefore, all additional factors of the shot will be detected only when examining the wound channel (“everything is inside, nothing is outside”). Powders, traces of soot, gun grease, traces of metal will be found along the wound channel.
If there is a dense tissue under the skin, such as bone, then gases, breaking through into the wound channel, spread over the surface of the bone, exfoliating the muscles and periosteum from it. At the same time, the skin is lifted by gases and pressed down to a piece cut, forming an imprint of the latter (stamps, stamp-imprints).
The most consistent signs of a point-blank shot are skin tears at the entry hole. These gaps are formed mainly due to pre-bullet gases flying out of the bore.
In cases where the muzzle of the weapon is not pressed, but only touches the body with its surface, the described signs of a point-blank shot will be less pronounced. In this case, part of the powder gases breaks through between the skin and the muzzle, giving a small coating of soot around the inlet. If at the time of the shot the weapon was pressed at an angle, then the powder gases and soot partially break out at the open corner, forming a triangular or oval area of sooting. Therefore, by the location of the soot in the area of the inlet, one can judge the position of the weapon at the time of the shot.
CLOSE SHOT.
A close distance is understood as such a distance when not only a bullet, but also additional factors of a shot act on the body: flame, gases, soot, powders, grease. As you move away from the weapon, additional factors dissipate in the form of a cone, expanding in the direction of the bullet's flight. The nature and magnitude of the muzzle flame depend primarily on the type of gunpowder. Black (smoky) powder gives a significant flame and a lot of red-hot unburned powders, which have a significant thermal effect. They can cause singed hair, skin burns, and even clothes on fire. There is a known case of suicide from a revolver loaded with black powder, when clothes and a sofa, on which the corpse of the deceased was located, caught fire from the shot.
The thermal effect of smokeless powder is much less pronounced. Hot powder gases, flying out of the barrel bore, have a bruising effect, causing the formation of parchment stains. The soot resulting from the combustion of gunpowder extends 20-30 cm from the muzzle of the weapon.
The shape of the soot spot can be round or oval, depending on the angle at which the shot occurred in relation to the obstacle.
When fired, the powder does not completely burn out, and therefore unburned and partially burnt powders fly out of the bore and, at close firing distances, are found on the barrier. They can penetrate into the fabric of clothing and even pierce it. Powders can damage the epidermis, causing it to settle. Sometimes they are embedded in the skin, where they are easily detected, the so-called gunpowder tattoo. Powders are found when shot from a distance of 60-70 cm (for short-barreled rifled weapons - revolvers, pistols) and up to 100 cm (for long-barreled - rifles, carbines).
When fired from lubricated weapons, additional factors include particles of gun grease. When shot at close range, they are found around the inlet.
The amount of close shot distance depends on the weapon system, the nature of the ammunition, and the degree of deterioration of the weapon. In practice, traces of additional factors of firing cartridges with smokeless powder from small arms are determined within 100 cm.
In the absence of traces of additional factors of the shot in the conclusion, the expert indicates that no signs of a shot at close range were found. The absence of traces of additional factors does not yet mean that the shot could not have been at close range, since it could have come through some kind of obstacle. For example, when shooting close to the door held by the body of a person on the other hand, additional factors will remain on the door. A similar picture can be observed with crossbows through various gaskets.
SHOT FROM A FAR (not close) DISTANCE.
A shot from a long distance in forensic medicine and criminology is understood as a shot from such a distance when only a bullet acts on the body, and additional factors of the shot (soot, powders, etc.) are not detected. For hand-held combat weapons, such a distance will begin already beyond 1 m. As for the specific distance of a long-range shot (10 or 100 m), it is not possible to determine it from the autopsy data.
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