J.M. Saloom FIREARMS/TOOLMARKS ACDLA SUMMER SEMINAR Joseph M. Saloom.
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Transcript of J.M. Saloom FIREARMS/TOOLMARKS ACDLA SUMMER SEMINAR Joseph M. Saloom.
J.M. Saloom
FIREARMS/TOOLMARKS FIREARMS/TOOLMARKS
ACDLA SUMMER SEMINAR
Joseph M. Saloom
J.M. Saloom
Alabama Department of Forensic Sciences
Brief History
J.M. SaloomJ.M. Saloom - ADFS Montgomery
History
• Created by legislative action in 1935
• Created because of need for scientific evidence.
• Set up as a law enforcement agency
• Set up as a separate department
• Originally set up to help with deaths of humans and animals
J.M. Saloom
Alabama Department of Forensic Sciences
• Firearms / Toolmarks Laboratories:
• Huntsville
• Birmingham
• Montgomery
• Mobile
J.M. Saloom
FIREARMS/TOOLMARKS
• The firearms / toolmarks examiner is responsible for comparing bullets and cartridge cases to a particular weapon or to each other. Examination of clothing for gunpowder residue, and comparing pry marks, cuts, impressions and saw marks back to a particular tool.
J.M. Saloom
• The scientific theory/basis that we operate under, is that no two items in nature are microscopically identical. Therefore, it follows that no two man-made items are microscopically identical, and we may make determinations based on microscopic comparisons.
J.M. Saloom
Routine firearm examinations and results:
• Caliber
• Make of weapon
• Weapon type and model
• Safety features and whether they work
• Capacity
• Trigger pull
• Proper function
Cartridge
J.M. Saloom
BULLET
POWDER
CARTRIDGE CASE
PRIMER CUP
FLASH HOLE
ANVIL
Louise Walzer, JPSO Crime Lab
Rimfire Cartridge
J.M. Saloom
BLANK DRILLED BARREL
RIFLEDRIFLED BARRELBARREL
Cross Section of gun barrel 6 lands and grooves
Lands of the barrel
Grooves of the barrel
Cross Section of unrifled gun barrel
Louise Walzer, JPSO Crime Lab
J.M. Saloom
CUTTING BLADES(note imperfections)
BROACH RIFLING METHOD
Louise Walzer, JPSO Crime Lab
J.M. Saloom
Front view
Side view
Button Rifling
The button is made of solid carbide and is larger than the reamed bore of the gun barrel.
Louise Walzer, JPSO Crime Lab
Rifling
J.M. Saloom
-Louise Walzer, JPSO Crime Lab
J.M. Saloom
-Louise Walzer, JPSO Crime Lab
J.M. Saloom
Louise Walzer, JPSO Crime Lab
J.M. Saloom
MEASURED WIDTH OF BULLET LAND
MEASURED WIDTH OF BULLET GROOVE
Winchester 38 special caliber lead bullet•Q-load•134 grains•six lands and grooves•right twist(possible revolvers: Rossi, Taurus, Spesco)(possible derringers: Excam, Hy-Hunter F.I.E., E.I.G.)bu
llet l
and
bulle
t gro
ove
Louise Walzer, JPSO Crime Lab
Important information for the “no gun” case...
Comparison Microscope
BULLET COMPARISON
J.M. Saloom
Louise Walzer, JPSO Crime Lab
J.M. Saloom
-The firing pin is recessed
The firing pin strikes the primer, sending the bullet down the barrel.
The back of the primer is slammed back onto the breech.
Louise Walzer, JPSO Crime Lab
J.M. Saloom
Firing PinStriking Primer
Louise Walzer, JPSO Crime Lab
J.M. Saloom
Breech Firing Pin
J.M. Saloom
Breech
Firing Pin
Extractor
Louise Walzer, JPSO Crime Lab
J.M. Saloom
Slide
Ejection port
Extractor
Rearward movement of Slideafter cartridge has been fired
Ejection of Fired Cartridge Case
Breech
J.M. Saloom
38S P L
-R P
FIRED CARTRIDGE CASE
BREECH MARKS
FIRING PINIMPRESSION
Louise Walzer, JPSO Crime Lab
CARTRIDGE CASE COMPARISON
Cartridge Case Comparison
Shotshell
J.M. Saloom
Shotshell components
J.M. Saloom
J.M. Saloom
Additional firearm related examinations
• Clothing examination for gunpowder
• Location of holes and other defects in clothing
• Serial number restoration
• Ballistic determinations
• Fingerprints
Gunshot Residue
Gunshot hole in shirt
Gunpowder Particles
J.M. Saloom
J.M. Saloom
J.M. Saloom
J.M. Saloom
J.M. Saloom
J.M. Saloom
Toolmarks examinations and results
• What type of tool was involved
• Could the tool submitted make the mark in question
• Comparison and determination of toolmark match
Toolmark
J.M. Saloom
J.M. Saloom
J.M. Saloom
J.M. Saloom
J.M. Saloom
Additional toolmark related examinations
• Wire striation matches
• Fracture matches
Wire cover extrusion marks