Criminalistics and Ballistics (PDF)

CRIMINALISTICS Analyzing and interpreting evidence using the natural sciences. forensics “Forum” which means market place or public gathering. Relating to or dealing with the application of scientific knowledge to legal problems. Origin of “Ballistic”  BALLISTIC –Gigantic bow...

CRIMINALISTICS Analyzing and interpreting evidence using the natural sciences. forensics “Forum” which means market place or public gathering. Relating to or dealing with the application of scientific knowledge to legal problems. Origin of “Ballistic”  BALLISTIC –Gigantic bow or Catapult used for throwing stone. “Ballista” Latin Ballistes, from Ballein“to throw” Greek Words BRIEF HISTORY OF BALLISTIC 1835 –1 ST case of forensic firearm examination documented. (Henry Goddard) 1845 –through the bullet that stuck on the eye of NAPOLEON BONAPARTE’s grandfather, the traces of gunpowder and its value were discovered. (HANS GROSS) 1860 –newspaper wads were found in the victims wound made of the same newspaper found at the suspect’s house. 1902 –use of magnifying glass to examine test bullet that fired from cotton wool and compare its striations with bullet found from the victim BRIEF HISTORY OF BALLISTIC Through the aid of photography, significant markings on the fired bullet and cartridge were also evaluated. 1915 –reevaluated the evidence in the Stielow Case BRIEF HISTORY OF BALLISTIC 1925 –comparison Microscope developed and Helixometerwas invented BRIEF HISTORY OF BALLISTIC 1932 –FBI Lab was established (1Firearm st Identification Professional)  3 types of Motion Direct-forward motion of the bullet Rotatory-action passing of bullet through a rifled bore barrel firearm Translational-action of bullet once it hits the target and subsequently ricocheted.  Branches of Ballistic Internal External Transitional Terminal  INTERNAL BALLISTICS F.I.C.E.P.E.R.V.R.E. 1.Firing pin hitting the primer 2.Ignition of the priming mixture 3.Combustion of gun powder 4.Expansion of heated gas 5.Pressure developed 6.Energy generated 7.Recoil of gun 8.Velocity of bullet while inside the barrel 9.Rotation of bullet 10.Engraving the bullet of the cylindrical surface of  INTERIOR BALLISTICS 2. IGNTION OF PRIMING MIXTURE Priming Mixture located in primer cup Percussion “Alexander John Forsyth” Hangfire  INTERIOR BALLISTICS 3. COMBUSTION OF GUNPOWDER Combustion (production of fire/heat) Vent or Flash Hole  INTERIOR BALLISTICS 4. EXPANSION OF HEATED GAS CHAMBER –cartridge is loaded 5. PRESSURE DEVELOPED 6. ENERGY GENERATED 7. VELOCITY 8. ROTATION – gyroscopic stability  9. ENGRAVING 10. RECOIL –MAJOR –equal and opposite reaction while MINOR equal and backward movement of the pistol slide TRANSITIONAL BALLISTICS Muzzle blast noise created at the muzzle point Muzzle flash –light created 3. EXTERIOR BALLISTIC Muzzle Energy Trajectory Range Accurate Range-distance within which the shooter has control of his shots. Effective Range-when the bullet was fired it is still capable of inflicting fatal injury. Maximum Range-The farthest distance the bullet could travel. Maximum effective Range–farthest distance that the bullet can inflict fatal injury. PARABOLA–ARC/CURVED PATTERN UNTIL IT REACHES THE BACK CURVE BACK CURVE –PORTION WHERE BULLET DROP TO THE GROUND DUE TO GRAVITY Velocityrate of speed of bullet per unit of time Pull of gravity the downward reaction of the bullet towards the straight surface due to its weight. Air resistance force of the air encounter by the bullet in its flight