Ballistics Powders Weapons Projectiles
Powders
Fire of Discovery - powders <ul><li>dirt with sulfur in it will sizzle and pop with lit on fire </li></ul><ul><li>Chinese ...
Fire of Discovery - powders <ul><li>12 th  Century and on… </li></ul><ul><ul><li>realization that this mixture could make ...
Refining Gunpowder <ul><li>for hand held guns, improvements needed because carbon, sulfur and saltpeter all had different ...
Refining Gunpowder <ul><li>ingredients could be made to stick together by mixing gunpowder with brandy and letting the res...
Weapons
Early Firearms <ul><li>1364 – First recorded use of firearm </li></ul><ul><li>1380 – hand guns known across Europe </li></ul>
Early Firearms <ul><li>at this point, guns were fired by holding a burning wick to a “touch hole” in the barrel igniting t...
Matchlock – 1400’s <ul><li>matchlock guns hold powder in a flash pan and is ignited by a wick (or match) in a movable clam...
Matchlock – 1400’s
Wheel Lock  - 1509 <ul><li>generate a spark mechanically, no wick to keep lit </li></ul><ul><li>easier to use, more reliab...
Wheel Lock  - 1509
Rifling - 1540 <ul><li>barrel (bore) of gun created with ridges (lands) and hollows (grooves) </li></ul><ul><li>these land...
Rifling - 1540
Rifling - 1540 <ul><li>bores can then be described by the </li></ul><ul><ul><li>bore diameter (measured from tops of lands...
Rifling - 1540 <ul><li>rifling also allows us to describe twist rates – the distance the bullet must travel to complete on...
Rifling - 1540 <ul><li>forensic experts can use the scratch marks (called toolmarks) left from the bore to individualize e...
Flintlock - 1630 <ul><li>solves the problem of having to remove pan cover manually </li></ul><ul><li>a flintlock mechanism...
Percussion Caps - 1825 <ul><li>firing mechanism no longer uses flash pan, instead has a tube leading straight into the gun...
Size Does Matter! <ul><li>Decimation of Target </li></ul><ul><li>Fire Power </li></ul>
Projectiles
Bullet vs. Cartridge <ul><li>a bullet (projectile) is the piece ejected from the barrel of the gun </li></ul><ul><li>a car...
Cartridges <ul><li>primer is struck by firing pin </li></ul><ul><li>primer ignites powder </li></ul>
Cartridges in Identification <ul><li>manufacturer </li></ul><ul><li>type/size </li></ul><ul><ul><li>22 blank, 22 Short, 22...
Bullets <ul><li>described by caliber </li></ul><ul><ul><li>diameter of bullet in hundredths of an inch </li></ul></ul><ul>...
Bullets <ul><li>balance between penetration and expansion is main idea of bullet construction </li></ul><ul><ul><li>too li...
Bullets - Construction <ul><li>shape and material are key to identification </li></ul><ul><li>bullets usu. made of  </li><...
Bullets - Construction <ul><li>non-jacketed bullets </li></ul><ul><ul><li>usu. lead </li></ul></ul><ul><ul><li>may have th...
Bullets - Construction <ul><li>jacketed bullets </li></ul><ul><ul><li>thick layer over a central core </li></ul></ul><ul><...
Bullets - Shape <ul><li>shape determines aerodynamics </li></ul><ul><li>shape determines impact characteristics </li></ul>...
Bullets – Solid Nosed <ul><li>have solid nose and remain fairly intact when they strike soft targets </li></ul><ul><li>oft...
Bullets – Hollow Point <ul><li>if bullet is manufactured with a hollow tip, it will mushroom and expand on impact  </li></...
Bullets in Identification <ul><li>manufacturer </li></ul><ul><ul><li>construction </li></ul></ul><ul><ul><ul><li>shape  </...
Class & Individual ID <ul><li>Class Characteristics </li></ul><ul><ul><li>rifling </li></ul></ul><ul><ul><li>caliber </li>...
Gun Shot Wounds  <ul><li>many determining factors </li></ul><ul><ul><li>distance </li></ul></ul><ul><ul><li>weapon/caliber...
Gun Shot Wounds <ul><li>contact wound  </li></ul><ul><ul><li>may display star shaped pattern </li></ul></ul><ul><ul><li>of...
Gun Shot Wounds <ul><li>close/intermediate range shot </li></ul><ul><ul><li>often with “tattooing” or “stippling” from the...
Gun Shot Wounds <ul><li>distant shot </li></ul><ul><ul><li>usually without tattooing  </li></ul></ul><ul><ul><li>usually w...
GSW - Damage <ul><li>degree of damage depends on  </li></ul><ul><ul><li>elasticity of tissues/organs </li></ul></ul><ul><u...
GSW - Damage <ul><li>damage caused mainly by </li></ul><ul><ul><li>tumbling motion of bullet </li></ul></ul><ul><ul><li>ca...
GSW - Damage <ul><li>cavities </li></ul><ul><ul><li>temporary cavity caused by cavitation </li></ul></ul><ul><ul><li>perma...
GSW - Damage <ul><li>elasticity </li></ul><ul><ul><li>extent of damage depends on whether  the transient (temporary) expan...
<ul><li>lock, stock and barrel </li></ul><ul><li>flash in the pan </li></ul><ul><li>going off at half cock </li></ul>
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Ballistics & Toolmark Analysis

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Ballistics & Toolmark Analysis

  1. 1. Ballistics Powders Weapons Projectiles
  2. 2. Powders
  3. 3. Fire of Discovery - powders <ul><li>dirt with sulfur in it will sizzle and pop with lit on fire </li></ul><ul><li>Chinese added concentrated sulfur to charcoal </li></ul><ul><li>by the 9 th Century AD, potassium nitrate crystals (saltpeter) was added </li></ul><ul><ul><li>burn the mixture for sparkly effects </li></ul></ul><ul><ul><li>Taoist monks played with these chemicals to create true fireworks </li></ul></ul>
  4. 4. Fire of Discovery - powders <ul><li>12 th Century and on… </li></ul><ul><ul><li>realization that this mixture could make stuff fly </li></ul></ul><ul><ul><ul><li>armies of Sung Dynasty added grenades to arsenals </li></ul></ul></ul><ul><ul><ul><li>fragmentations bombs created </li></ul></ul></ul><ul><ul><ul><li>military rockets and bombs </li></ul></ul></ul><ul><ul><ul><ul><li>some filled with poisons </li></ul></ul></ul></ul><ul><ul><ul><ul><li>some filled with oil to start fires upon impact </li></ul></ul></ul></ul>
  5. 5. Refining Gunpowder <ul><li>for hand held guns, improvements needed because carbon, sulfur and saltpeter all had different weights </li></ul><ul><ul><li>saltpeter would drop and carbon rise to the top = misfire </li></ul></ul><ul><li>could load weapon right before firing </li></ul><ul><ul><li>time consuming </li></ul></ul><ul><ul><li>difficult </li></ul></ul>
  6. 6. Refining Gunpowder <ul><li>ingredients could be made to stick together by mixing gunpowder with brandy and letting the resulting paste dry into corns or “grains” </li></ul><ul><li>waste of brandy so other items were used </li></ul><ul><ul><li>vinegar </li></ul></ul><ul><ul><li>urine </li></ul></ul>
  7. 7. Weapons
  8. 8. Early Firearms <ul><li>1364 – First recorded use of firearm </li></ul><ul><li>1380 – hand guns known across Europe </li></ul>
  9. 9. Early Firearms <ul><li>at this point, guns were fired by holding a burning wick to a “touch hole” in the barrel igniting the powder </li></ul><ul><li>one hand to aim, one to ignite, and a prop to hold the gun </li></ul>
  10. 10. Matchlock – 1400’s <ul><li>matchlock guns hold powder in a flash pan and is ignited by a wick (or match) in a movable clamp </li></ul><ul><li>both hands on the gun improves aim </li></ul><ul><li>pan cover still needs to be removed manually </li></ul>
  11. 11. Matchlock – 1400’s
  12. 12. Wheel Lock - 1509 <ul><li>generate a spark mechanically, no wick to keep lit </li></ul><ul><li>easier to use, more reliable </li></ul><ul><li>very expensive to produce, pan cover still had to be removed manually </li></ul>
  13. 13. Wheel Lock - 1509
  14. 14. Rifling - 1540 <ul><li>barrel (bore) of gun created with ridges (lands) and hollows (grooves) </li></ul><ul><li>these lands and grooves spiraled bore – the spin increases stability & accuracy at further distances </li></ul>
  15. 15. Rifling - 1540
  16. 16. Rifling - 1540 <ul><li>bores can then be described by the </li></ul><ul><ul><li>bore diameter (measured from tops of lands) </li></ul></ul><ul><ul><li>groove diameter (measured from bottom of grooves) </li></ul></ul><ul><li>some confusion </li></ul><ul><ul><li>.303 British vs </li></ul></ul><ul><ul><li>.308 Winchester </li></ul></ul>
  17. 17. Rifling - 1540 <ul><li>rifling also allows us to describe twist rates – the distance the bullet must travel to complete one full revolution </li></ul><ul><ul><li>1:10 inches or 1:30 cm </li></ul></ul><ul><ul><li>shorter distance means a “faster” twist </li></ul></ul><ul><li>length of projectile determines twist rate needed to stabilize it </li></ul>
  18. 18. Rifling - 1540 <ul><li>forensic experts can use the scratch marks (called toolmarks) left from the bore to individualize evidence </li></ul>
  19. 19. Flintlock - 1630 <ul><li>solves the problem of having to remove pan cover manually </li></ul><ul><li>a flintlock mechanism moves the lid and sparks a flint at the same time </li></ul><ul><li>this design remained relatively unchanged for two centuries </li></ul>
  20. 20. Percussion Caps - 1825 <ul><li>firing mechanism no longer uses flash pan, instead has a tube leading straight into the gun barrel </li></ul><ul><li>the tube had an explosive cap on it that exploded when struck </li></ul>
  21. 21. Size Does Matter! <ul><li>Decimation of Target </li></ul><ul><li>Fire Power </li></ul>
  22. 22. Projectiles
  23. 23. Bullet vs. Cartridge <ul><li>a bullet (projectile) is the piece ejected from the barrel of the gun </li></ul><ul><li>a cartridge is a single unit of ammunition consisting of </li></ul><ul><ul><li>cartridge case </li></ul></ul><ul><ul><li>primer </li></ul></ul><ul><ul><li>propellant </li></ul></ul><ul><ul><li>may or may not contain projectile </li></ul></ul>
  24. 24. Cartridges <ul><li>primer is struck by firing pin </li></ul><ul><li>primer ignites powder </li></ul>
  25. 25. Cartridges in Identification <ul><li>manufacturer </li></ul><ul><li>type/size </li></ul><ul><ul><li>22 blank, 22 Short, 22 Long, 22 Long Rifle Shot, 22 Viper, 22 Long Rifle, 22 Stinger, 22 Magnum, and 22 Maximum </li></ul></ul>
  26. 26. Bullets <ul><li>described by caliber </li></ul><ul><ul><li>diameter of bullet in hundredths of an inch </li></ul></ul><ul><ul><ul><li>bullet 30 hundredths of an inch (.30) is called a 30 caliber bullet </li></ul></ul></ul><ul><ul><ul><li>this is an English derived system and used by manufacturers in the US </li></ul></ul></ul><ul><ul><ul><li>in Europe, the metric system is used and a 30 caliber bullet would be called a 7.62mm bullet </li></ul></ul></ul>
  27. 27. Bullets <ul><li>balance between penetration and expansion is main idea of bullet construction </li></ul><ul><ul><li>too little penetration and internal organs not reached </li></ul></ul><ul><ul><li>too much penetration and bullet can pass through target & energy is wasted down range </li></ul></ul><ul><ul><li>hollow point demo </li></ul></ul>
  28. 28. Bullets - Construction <ul><li>shape and material are key to identification </li></ul><ul><li>bullets usu. made of </li></ul><ul><ul><li>single metal alloy – non jacketed </li></ul></ul><ul><ul><li>layered combination of various materials (copper, lead, brass, bronze, steel, aluminum) – these are called jacketed bullets </li></ul></ul>
  29. 29. Bullets - Construction <ul><li>non-jacketed bullets </li></ul><ul><ul><li>usu. lead </li></ul></ul><ul><ul><li>may have thin coating </li></ul></ul><ul><ul><li>newer manufacturing has increased types </li></ul></ul>
  30. 30. Bullets - Construction <ul><li>jacketed bullets </li></ul><ul><ul><li>thick layer over a central core </li></ul></ul><ul><ul><ul><li>most common core is lead </li></ul></ul></ul><ul><ul><ul><li>most common jacket is copper </li></ul></ul></ul><ul><ul><li>usu. have a hole at base or nose </li></ul></ul><ul><ul><ul><li>those w/o the opening are called TMJ (total metal jacket) or encapsulated bullets </li></ul></ul></ul>
  31. 31. Bullets - Shape <ul><li>shape determines aerodynamics </li></ul><ul><li>shape determines impact characteristics </li></ul><ul><li>bases </li></ul><ul><ul><li>banded </li></ul></ul><ul><ul><li>tapered (boat-tail) </li></ul></ul><ul><ul><li>expanded base </li></ul></ul>
  32. 32. Bullets – Solid Nosed <ul><li>have solid nose and remain fairly intact when they strike soft targets </li></ul><ul><li>often pass through target unless they hit bone </li></ul><ul><li>other common types of solid nose include “wadcutters” </li></ul>
  33. 33. Bullets – Hollow Point <ul><li>if bullet is manufactured with a hollow tip, it will mushroom and expand on impact </li></ul><ul><ul><li>slows the bullet </li></ul></ul><ul><ul><li>a bullet that expends all energy in target is more efficient and does more damage </li></ul></ul>
  34. 34. Bullets in Identification <ul><li>manufacturer </li></ul><ul><ul><li>construction </li></ul></ul><ul><ul><ul><li>shape </li></ul></ul></ul><ul><ul><ul><ul><li>nose </li></ul></ul></ul></ul><ul><ul><ul><ul><li>base </li></ul></ul></ul></ul><ul><ul><li>materials </li></ul></ul><ul><ul><li>jacketed vs. unjacketed </li></ul></ul><ul><li>weight </li></ul><ul><li>diameter </li></ul>
  35. 35. Class & Individual ID <ul><li>Class Characteristics </li></ul><ul><ul><li>rifling </li></ul></ul><ul><ul><li>caliber </li></ul></ul><ul><li>Individual Characteristics </li></ul><ul><ul><li>breech marks </li></ul></ul><ul><ul><li>firing pin impressions </li></ul></ul><ul><ul><li>extractor marks </li></ul></ul><ul><ul><li>ejector marks </li></ul></ul>
  36. 36. Gun Shot Wounds <ul><li>many determining factors </li></ul><ul><ul><li>distance </li></ul></ul><ul><ul><li>weapon/caliber </li></ul></ul><ul><ul><li>site of wound </li></ul></ul>
  37. 37. Gun Shot Wounds <ul><li>contact wound </li></ul><ul><ul><li>may display star shaped pattern </li></ul></ul><ul><ul><li>often with GSR in the wound </li></ul></ul><ul><ul><li>may show muzzle impressions </li></ul></ul>
  38. 38. Gun Shot Wounds <ul><li>close/intermediate range shot </li></ul><ul><ul><li>often with “tattooing” or “stippling” from the gunpowder </li></ul></ul><ul><ul><li>histology </li></ul></ul>
  39. 39. Gun Shot Wounds <ul><li>distant shot </li></ul><ul><ul><li>usually without tattooing </li></ul></ul><ul><ul><li>usually without abrasions/star shaped patterns </li></ul></ul>
  40. 40. GSW - Damage <ul><li>degree of damage depends on </li></ul><ul><ul><li>elasticity of tissues/organs </li></ul></ul><ul><ul><li>type of bullet ( solid vs. hollow point ) </li></ul></ul><ul><ul><li>velocity of bullet </li></ul></ul><ul><ul><li>fragmentation of bullet </li></ul></ul><ul><li>entrance and exit wounds may be small with large wound cavity </li></ul>
  41. 41. GSW - Damage <ul><li>damage caused mainly by </li></ul><ul><ul><li>tumbling motion of bullet </li></ul></ul><ul><ul><li>cavitation in the tissue </li></ul></ul>
  42. 42. GSW - Damage <ul><li>cavities </li></ul><ul><ul><li>temporary cavity caused by cavitation </li></ul></ul><ul><ul><li>permanent cavity remains after temporary cavity collapses – may be much larger than bullet </li></ul></ul>
  43. 43. GSW - Damage <ul><li>elasticity </li></ul><ul><ul><li>extent of damage depends on whether the transient (temporary) expansion of tissues/organs exceeds their elasticity </li></ul></ul><ul><ul><ul><li>liver and spleen which lack elasticity are easily lacerated </li></ul></ul></ul><ul><ul><ul><li>stomach and intestines are more elastic and more likely to sustain contusions </li></ul></ul></ul><ul><ul><li>video </li></ul></ul><ul><ul><li>Mythbusters – ballistics gel </li></ul></ul>
  44. 44. <ul><li>lock, stock and barrel </li></ul><ul><li>flash in the pan </li></ul><ul><li>going off at half cock </li></ul>

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