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Forensic Medicine. Firearm

Forensic Medicine. Firearm

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Forensic Medicine. Firearm

  1. 1. BASES OF FORENSIC MEDICALBASES OF FORENSIC MEDICAL TRAUMATOLOGY: firearmTRAUMATOLOGY: firearm
  2. 2. Ballistics is the science of the motion ofBallistics is the science of the motion of a projectilea projectile.. Exterior ballisticsExterior ballistics is the study of motion ofis the study of motion of a projectile after it leaves the barrel of aa projectile after it leaves the barrel of a firearm.firearm. Interior ballisticsInterior ballistics is the study of physico-is the study of physico- chemical phenomena within the firearmchemical phenomena within the firearm from the moment of detonation of primerfrom the moment of detonation of primer to the time the projectile leaves the barrel.to the time the projectile leaves the barrel. Terminal ballisticsTerminal ballistics is the study of theis the study of the effect of impact of a projectile on theeffect of impact of a projectile on the target (resulting in wound formation -target (resulting in wound formation - wound ballistics).wound ballistics).
  3. 3. FirearmFirearm is a specialized device designed tois a specialized device designed to propel a projectile (shot/bulletpropel a projectile (shot/bullet missile) by the expansive force ofmissile) by the expansive force of gases generated as a result ofgases generated as a result of combustion of the propellantcombustion of the propellant (powder) at its base in a closed(powder) at its base in a closed space.space.
  4. 4. ShotgunShotgun
  5. 5. SponsoredSponsored Medical Lecture Notes –Medical Lecture Notes – All SubjectsAll Subjects USMLE Exam (America) –USMLE Exam (America) – PracticePractice
  6. 6. A – the of the trigger releases aA – the of the trigger releases a pin or hummer whose tip strikespin or hummer whose tip strikes the percussion cap containingthe percussion cap containing the sensitive primer at the basethe sensitive primer at the base of the cartridge.of the cartridge. B – the primer is detonatedB – the primer is detonated C – the detonation of the primerC – the detonation of the primer ignites the main propellantignites the main propellant charge.charge. D – the ignition of the mainD – the ignition of the main propellant charge results in anpropellant charge results in an explosive formation of hotexplosive formation of hot gases at very high pressure.gases at very high pressure. The pressure of the expandingThe pressure of the expanding gases builds up to an optimumgases builds up to an optimum value and it forces the missilevalue and it forces the missile out of the barrel.out of the barrel.
  7. 7. Shotgun cartridgeShotgun cartridge
  8. 8. Classification of Firearms:Classification of Firearms: FirearmsFirearms are sectioned on:are sectioned on: artilleryartillery shootingshooting Shooting may be 2 types:Shooting may be 2 types: group (machine guns,group (machine guns, mortars)mortars) individual (hand)individual (hand)
  9. 9. Classification of firearms:Classification of firearms: The individual shooting firearms are sectionedThe individual shooting firearms are sectioned into follow groups:into follow groups: 1) according to reserving-1) according to reserving- Battle (automatic devices, carbines, pistols,Battle (automatic devices, carbines, pistols, rifles);rifles); Hunting (1-, 2-, 3-, 4-barreled guns);Hunting (1-, 2-, 3-, 4-barreled guns); Sports (rifles, pistols, revolvers);Sports (rifles, pistols, revolvers); Special (alarm, construction pistols).Special (alarm, construction pistols). Atipical: self-made and defect.Atipical: self-made and defect. 2) according to length of a barrel:2) according to length of a barrel: Long-barrelled (rifles, carbines, machine guns,Long-barrelled (rifles, carbines, machine guns, pistols - machine guns, hunting rifles);pistols - machine guns, hunting rifles); Short-barreled (automatic pistols, revolvers).Short-barreled (automatic pistols, revolvers).
  10. 10. Atypical firearmsAtypical firearms
  11. 11. Classification of firearms:Classification of firearms: 3) according to property of a barrel:3) according to property of a barrel: а) Rifled (rifles, automatic pistols, revolvers);а) Rifled (rifles, automatic pistols, revolvers); б) Smooth-bored weapons (shotgun);б) Smooth-bored weapons (shotgun); в) Combined (hunting rifles, sports guns).в) Combined (hunting rifles, sports guns). 4) according to calibre (diameter):4) according to calibre (diameter): а) Small-calibre (4-6 mm);а) Small-calibre (4-6 mm); б) Medium-caliber (7-9 mm);б) Medium-caliber (7-9 mm); в) Large-calibre (more than 9 mm).в) Large-calibre (more than 9 mm). 5) according to the mechanism of a shot:5) according to the mechanism of a shot: а) Automatic (machine guns);а) Automatic (machine guns); б) Semi-automatic (pistols, carbines);б) Semi-automatic (pistols, carbines); в) Not automatic (hunting rifles).в) Not automatic (hunting rifles).
  12. 12. Smooth-bored weapons (shotgun)Smooth-bored weapons (shotgun) TheThe borebore (sometimes called(sometimes called gauge)gauge) isis measured by the internal diameter inmeasured by the internal diameter in inches or by the number of lead balls ofinches or by the number of lead balls of size almost fitting the barrel, which can besize almost fitting the barrel, which can be made from one pound of lead.made from one pound of lead. The most common bore isThe most common bore is a 12a 12 bore.bore. Thus, the 12 bore gun is one whose boreThus, the 12 bore gun is one whose bore diameter is that of a ball of lead of such adiameter is that of a ball of lead of such a size those 12 balls can be made from onesize those 12 balls can be made from one pound of lead. It is obvious that the greaterpound of lead. It is obvious that the greater the bore number, the smaller the size of thethe bore number, the smaller the size of the lead shot, and vice versa.lead shot, and vice versa.
  13. 13. Rifled firearms.Rifled firearms. In these weapons, the inside of the bore is rifled,In these weapons, the inside of the bore is rifled, that is, cut longitudinally with a number of spiralthat is, cut longitudinally with a number of spiral grooves which run parallel to each other, but aregrooves which run parallel to each other, but are twisted spirally from chamber end to muzzletwisted spirally from chamber end to muzzle end. This is calledend. This is called rifling.rifling. The raised portions on the bore are calledThe raised portions on the bore are called landslands and the lowered ones theand the lowered ones the grooves.grooves. The distance between opposite fields of riflingThe distance between opposite fields of rifling grooves in millimeters refers to asgrooves in millimeters refers to as calibrecalibre of theof the weapon.weapon. The majority of the battle weapon has calibre fromThe majority of the battle weapon has calibre from 7 up to 9 mm and 4-6 rifling grooves.7 up to 9 mm and 4-6 rifling grooves.   
  14. 14. B  –  calibre  of  the B  –  calibre  of  the  rifled  bore.rifled  bore. The distance between The distance between  opposite  fields  of opposite  fields  of  rifling  grooves  in rifling  grooves  in  millimeters  refers  to millimeters  refers  to  as as  calibre calibre  of  the of  the  weapon.weapon.
  15. 15. MEDICO-LEGAL QUESTIONSMEDICO-LEGAL QUESTIONS 1.1. Is the injury caused by discharge of firearm?Is the injury caused by discharge of firearm? 2.2. What kind of weapon fired the shot? What kind of weapon fired the shot?  3.3. From  what  distance  and  direction  was  the  shot From  what  distance  and  direction  was  the  shot  fired?fired? 4.4. When was the firearm discharged? When was the firearm discharged?  5.5. Where an entrance and exit fire apertures?Where an entrance and exit fire apertures? 6.6. What direction of wound canal?What direction of wound canal? 7.7. How  many  shots  have  been  effected  also  what How  many  shots  have  been  effected  also  what  their sequence, what shot was fatal?their sequence, what shot was fatal? 8.8. Whether there are the signs directing drawing of Whether there are the signs directing drawing of  damage by own hand?damage by own hand?
  16. 16. "alive force" of a bullet"alive force" of a bullet The  flying  speed  of  a  bullet  of The  flying  speed  of  a  bullet  of  directly  proportional  its  kinetic directly  proportional  its  kinetic  energy  ("alive  force"  of  a  bullet) energy  ("alive  force"  of  a  bullet)  also  depends  on  a  kind  and  a also  depends  on  a  kind  and  a  condition  of  the  weapon,  quantity condition  of  the  weapon,  quantity  and quality of a powder charge and and quality of a powder charge and  distance of a shot. distance of a shot.  Distinguish  4  kinds  of  action  of  a Distinguish  4  kinds  of  action  of  a  bullet  on  an  organism  of  the bullet  on  an  organism  of  the  person:person:
  17. 17. (A) Penetrative -(A) Penetrative - it is observed at big "alive force" of a it is observed at big "alive force" of a  bullet which beating out a site of a bullet which beating out a site of a  tissue  forms  defect  (“minus  – tissue  forms  defect  (“minus  –  tissue” - by Райский). tissue” - by Райский).  At attempt to pull together edges of At attempt to pull together edges of  a wound between fingers of arms it a wound between fingers of arms it  is formed a pleat of skin.is formed a pleat of skin.
  18. 18. (B) Cuneiform action of a bullet(B) Cuneiform action of a bullet - takes  place  at  small  "alive  force"  of  a takes  place  at  small  "alive  force"  of  a  bullet; bullet;  - the  bullet  does  not  punch  and  moves the  bullet  does  not  punch  and  moves  apart tissues, forming a slit. apart tissues, forming a slit.  - As  opposed  to  penetrative  action  of  a As  opposed  to  penetrative  action  of  a  bullet  -  cuneiform  it  is  observed  at  a bullet  -  cuneiform  it  is  observed  at  a  exit  of  a  bullet  from  a  body  of  the exit  of  a  bullet  from  a  body  of  the  person more often.person more often.
  19. 19. (C) Explosive action of a bullet(C) Explosive action of a bullet -- can take place at shots of special-purpose can take place at shots of special-purpose  bullets  (explosive  bullets),  at  damages  of bullets  (explosive  bullets),  at  damages  of  a bullet covering, and also to cases, when a bullet covering, and also to cases, when  a bullet, having big "alive force", getting in a bullet, having big "alive force", getting in  the  self-contained  cavities  with  a  liquid the  self-contained  cavities  with  a  liquid  (the  filled  stomach),  liquid  tissues  (heart (the  filled  stomach),  liquid  tissues  (heart  in  a  condition  of  a  diastole),  organs  with in  a  condition  of  a  diastole),  organs  with  the  big  percentage  of  liquids  (brain).  In the  big  percentage  of  liquids  (brain).  In  that  case  under  action  of  arising that  case  under  action  of  arising  hydrodynamical  forces  (the  law  of  the hydrodynamical  forces  (the  law  of  the  Pascal)  there  are  extensive  destructions Pascal)  there  are  extensive  destructions  of these organs.of these organs.
  20. 20. (D) contusion action of a bullet(D) contusion action of a bullet is displayed at it small "alive force" is displayed at it small "alive force"  that  is  observed  at  actions  of that  is  observed  at  actions  of  bullets on exit, at a ricochet. bullets on exit, at a ricochet.  Such  bullets  usually  cause  grazes, Such  bullets  usually  cause  grazes,  superficial wounds.superficial wounds.
  21. 21. In a bullet wound it is accepted In a bullet wound it is accepted  to distinguish 3 zones:to distinguish 3 zones: 1. 1.   A zone of immediate wound canal  A zone of immediate wound canal  (initial destruction).(initial destruction). 2. 2.   A zone of a contusion of the tissues  A zone of a contusion of the tissues  being walls of the canal, width from being walls of the canal, width from  several mm up to 1-2 cm.several mm up to 1-2 cm. 3. 3.   A zone of molecular shake of the  A zone of molecular shake of the  tissue propagated sometimes on 4-5 cm tissue propagated sometimes on 4-5 cm  and more. and more. 
  22. 22. N. I. Pirogov (I8I0-I88I) -N. I. Pirogov (I8I0-I88I) - the Russian surgeon, on the basis of the bigthe Russian surgeon, on the basis of the big practical experience in treatment of firepractical experience in treatment of fire damages for the first time has describeddamages for the first time has described changes which are observed in the aeries ofchanges which are observed in the aeries of entrance and exit fire wounds that matters forentrance and exit fire wounds that matters for forensic medicine presently:forensic medicine presently: 1. About absence of differences in size of1. About absence of differences in size of entrance and exit gunshot wounds. (1875)entrance and exit gunshot wounds. (1875) 2.2. About defect of a tissue around an entranceAbout defect of a tissue around an entrance gunshot wound. (1859)gunshot wound. (1859) 3. About abrasion collar around an entrance3. About abrasion collar around an entrance gunshot wound. (1865)gunshot wound. (1865)
  23. 23. Distinguish 3 kinds Distinguish 3 kinds  of gunshot wounds:of gunshot wounds: tangential wound,tangential wound, nonperforating (blind),nonperforating (blind), through.through.
  24. 24. Penetrative    action  of  a  bullet  on  a  skin.Penetrative    action  of  a  bullet  on  a  skin.   Formation  of  Defect  "minus  -  tissue“, Formation  of  Defect  "minus  -  tissue“,  Abrasion Collar and “Grease or Dirt Collar"Abrasion Collar and “Grease or Dirt Collar"   
  25. 25. Entrance Wounds from Entrance Wounds from  ShotgunsShotguns
  26. 26. (A) abraded collar or contusion ring;(A) abraded collar or contusion ring; (B) grease/dirt collar;(B) grease/dirt collar; (C) powder distribution (tattoo marks);(C) powder distribution (tattoo marks); (D) blackening(D) blackening
  27. 27. wound canalwound canal The path, which has passed aThe path, which has passed a shell in a body, has the nameshell in a body, has the name the wound canalthe wound canal..
  28. 28. Wound canals can be divided on direct andWound canals can be divided on direct and indirect, intermittent and continuous.indirect, intermittent and continuous. TheThe directdirect continuous canal passes through allcontinuous canal passes through all organs on one line.organs on one line. InterruptedInterrupted canal it is formed due tocanal it is formed due to displacement of organs under the attitude todisplacement of organs under the attitude to each other.each other. IndirectIndirect canals are formed due to change ofcanals are formed due to change of bullet’s flying as a result of collision of abullet’s flying as a result of collision of a bullet with a bone, more dense tissues, etc.bullet with a bone, more dense tissues, etc. InterruptedInterrupted indirectindirect canals are at hit of acanals are at hit of a bullet in a cavity of a backbone, an intestine,bullet in a cavity of a backbone, an intestine, etc. in which it can pass any distance, andetc. in which it can pass any distance, and then exit in the other place.then exit in the other place.
  29. 29. In that case under action of arisingIn that case under action of arising hydrodynamical forces (the law of the Pascal)hydrodynamical forces (the law of the Pascal) there are extensive destructions of thesethere are extensive destructions of these organs.organs.
  30. 30. Contact shot on the head.Contact shot on the head. The gases from the explosion expandThe gases from the explosion expand between the scalp and scull resulting in abetween the scalp and scull resulting in a bursting effect and ragged entrancebursting effect and ragged entrance wound.wound.
  31. 31. For flat bones (the skull, a scapula,For flat bones (the skull, a scapula, flanks of ileal bones, and a sternum) theflanks of ileal bones, and a sternum) the most typical is a foramen fracturemost typical is a foramen fracture..
  32. 32. Wound canalWound canal researchresearch aa level-by-levellevel-by-level methodmethod during autopsy.during autopsy. Thus studyThus study character and frame of damages of tissuescharacter and frame of damages of tissues and organs,and organs, a direction of the canal,a direction of the canal, its contents;its contents; define deposition of additional factors,define deposition of additional factors, parts of a tissue of clothes and otherparts of a tissue of clothes and other foreign impurities;foreign impurities; conduct search of a fire shell and theconduct search of a fire shell and the secondary shells (fragments of bones, asecondary shells (fragments of bones, a part of the solid subjects available outside)part of the solid subjects available outside)
  33. 33. Shavinjy’s phenomenonShavinjy’s phenomenon In case of damage to flat bones it isIn case of damage to flat bones it is necessary to take intonecessary to take into consideration the course ofconsideration the course of fissures. The fissures, which werefissures. The fissures, which were produced by the next shot, do notproduced by the next shot, do not cross those ones, which werecross those ones, which were produced by the previous shotproduced by the previous shot
  34. 34. EXIT WOUNDEXIT WOUND The edges are freeThe edges are free from signs of:from signs of: defect "minus -defect "minus - tissue",tissue", burning,burning, blackening orblackening or tattooing,tattooing, no contusion orno contusion or abrasion collar.abrasion collar.
  35. 35. The variation in the shape and large size ofThe variation in the shape and large size of the exit wound are due to:the exit wound are due to: (1) The bullet tumbles in the body and fails to(1) The bullet tumbles in the body and fails to exit nose end first.exit nose end first. (2) The bullet is deformed.(2) The bullet is deformed. (3) The bullet breaks up in the tissues and exits(3) The bullet breaks up in the tissues and exits as several pieces.as several pieces. (4) Fragments of the bone may be blown out of(4) Fragments of the bone may be blown out of the body with the bullet.the body with the bullet. (5) The unsupported skin at the exit tends to(5) The unsupported skin at the exit tends to tear and break into pieces. Exit wounds oftear and break into pieces. Exit wounds of the head are usually star-shaped, resemblingthe head are usually star-shaped, resembling contact entrance wound.contact entrance wound.
  36. 36. distance of a shotdistance of a shot TheThe distance of a shotdistance of a shot is understood asis understood as distance between muzzle and a surfacedistance between muzzle and a surface of an injured body.of an injured body. In forensic medicine distinguish 3In forensic medicine distinguish 3 distances:distances: ••                                            contact shot,contact shot, ••                                            close shot,close shot, ••                                            distant shot.distant shot.
  37. 37. Additional factors of a shot and theirAdditional factors of a shot and their action on a skin around the entranceaction on a skin around the entrance woundwound Flame: 3-5 cm - burningFlame: 3-5 cm - burning Powder gases: 15-20 cm - formation ofPowder gases: 15-20 cm - formation of parchment spotsparchment spots Soot black: 20-40 cm - blackeningSoot black: 20-40 cm - blackening Unburnt and partially burnt powderUnburnt and partially burnt powder grains; small metallic particles: up to 1grains; small metallic particles: up to 1 meter - tattooingmeter - tattooing
  38. 38. Contact shotContact shot
  39. 39. Contact distance (blackening).Contact distance (blackening).
  40. 40. Clothing should be removed with careClothing should be removed with care keeping in mind the possibility of findingkeeping in mind the possibility of finding bullets/pellets in them.bullets/pellets in them.
  41. 41. Entrance wounds.Entrance wounds. Close distanceClose distance
  42. 42. Entrance wounds.Entrance wounds. Close distance (blackening).Close distance (blackening).
  43. 43. Distant Shot:Distant Shot: The entrance woundThe entrance wound
  44. 44. phenomenon by Vinogradovphenomenon by Vinogradov In some cases at a shot from a distantIn some cases at a shot from a distant distance it is possible to find outdistance it is possible to find out deposition of a soot black on inner layersdeposition of a soot black on inner layers of clothes or around of a skin at itsof clothes or around of a skin at its absence on surface layers of clothes.absence on surface layers of clothes. The basic conditions for such deposition of aThe basic conditions for such deposition of a soot black issoot black is presence of several traces of clothes, whichpresence of several traces of clothes, which be distant from each other up to 1-1,5 cm.be distant from each other up to 1-1,5 cm. and the big flying speed of a bullet (fromand the big flying speed of a bullet (from above 500 m/sec.).above 500 m/sec.).
  45. 45. Cause of death:Cause of death: Haemorrhage and injury to vital organs leadingHaemorrhage and injury to vital organs leading to shock are the common causes of death.to shock are the common causes of death. In abdominal wounds, infection is anotherIn abdominal wounds, infection is another common immediate cause of death.common immediate cause of death. Complications like peritonitis develop due toComplications like peritonitis develop due to leakage of contents from the gastrointestinalleakage of contents from the gastrointestinal tract and lead to death in due course.tract and lead to death in due course. Pneumonia develops frequently in headPneumonia develops frequently in head injuries with prolonged unconsciousness.injuries with prolonged unconsciousness. Hypostatic pneumonia develops in elderlyHypostatic pneumonia develops in elderly patients who are bed-ridden even for a fewpatients who are bed-ridden even for a few days.days.
  46. 46. BOMB EXPLOSION WOUNDSBOMB EXPLOSION WOUNDS A bomb is a container filled with anA bomb is a container filled with an explosive mixture and missiles, which isexplosive mixture and missiles, which is fired either by a detonator or a fuse. Whenfired either by a detonator or a fuse. When an explosion occurs, the explosivean explosion occurs, the explosive material produces a large volume of gasmaterial produces a large volume of gas and releases very large amount of energy.and releases very large amount of energy. Pressures of up to thousand tons per sq.Pressures of up to thousand tons per sq. inch can be produced.inch can be produced.
  47. 47. BOMB EXPLOSION WOUNDSBOMB EXPLOSION WOUNDS
  48. 48. BOMB EXPLOSION WOUNDSBOMB EXPLOSION WOUNDS A person can be injured by an explosion in aA person can be injured by an explosion in a number of ways.number of ways. (1) Disruptive Effects.(1) Disruptive Effects. (2)Burns.(2)Burns. (3) Air Blast.(3) Air Blast. (4) Flying Missiles.(4) Flying Missiles. (5) Falling Masonry.(5) Falling Masonry. (6) Fumes.(6) Fumes.
  49. 49. BOMB EXPLOSION WOUNDSBOMB EXPLOSION WOUNDS

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