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