Firearms and Tool Marks

Question 1

Shot Gun

Answer 1

has a long, thin, smooth barrel

Question 2

Land

Answer 2

part of a bullet or bore that is raised

Question 3

gunshot residue

Answer 3

gases, soot, unburned or partially burned gunpowder released when a shot is fired

Question 4

tool mark

Answer 4

any cut, scrape, impression, gouge, scratch, indentation or other mark left on an object or surface at a crime scene

Question 5

semi-autmatic

Answer 5

gun that fires a single round with a trigger pull and reloads itself

Question 6

caliber

Answer 6

the diameter of the bore or bullet

Question 7

shot

Answer 7

numerous round metal pellets

Question 8

smokeless

Answer 8

is the most common type of gunpowder used in ammunition today

Question 9

gunpowder

Answer 9

highly flammable material that pushes the projectile out of the gun barrel

Question 10

handgun

Answer 10

has a short, rifled barrel

Question 11

made up of a case, primer, powder, and bullet

Answer 11

cartridge

Question 12

microscopic markings left on the surface of a bullet

Answer 12

striations

Question 13

made up of a casing, shot, wad, powder and primer

Answer 13

shell

Question 14

groove

Answer 14

part of a bullet or bore that is pressed in

Question 15

spiral grooves impressed into the barrel of a firearm

Answer 15

rifling

Question 16

rifles

Answer 16

has a long, thick rifled barrel

Question 17

primer

Answer 17

substance that ignites the gunpowder after being struck by the firing pin

Question 18

crime lab firearm identification units provide knowledge on

Answer 18

operation of all types of weapons
recognition, of different types of ammunition
detection and characterization of gunpowder residue

Question 19

polygonal rifling

Answer 19

land and groove edges look rounded, older

Question 20

the trigger is pulled, causing the firing pin to strike the primer, then

Answer 20

the primer ignites the gunpowder inside the cartridge and the burning gunpowder produces gases which create pressure to propel the bullet through the barrel

Question 21

caliber

Answer 21

diameter

Question 22

to measure the land and groove characteristics you look at the

Answer 22

width, number, and twist

Question 23

breechface striations are

Answer 23

results from contact with the rear wall of the firing chamber

Question 24

firing impresssions

Answer 24

marked upon primer when the cartridge is stuck, shape is indented in the primer, rim of cartridge case

Question 25

extractor markings

Answer 25

usually found in a striated form, a hook that is used to remove a cartridge or cartridge case from the chamber of a firearm.

Question 26

ejector marks

Answer 26

shape impressed on the head stamp of cartridge case when pushed

Question 27

National integrated ballistic information network (NIBW)

Answer 27

database of digital microscopic images of spent bullets and cartridge casings from crime scenes or test fired

Question 28

Contact point black

Answer 28

muzzle of gun is touching victims skin or clothing, visible around bullet hole, tears in fabric, skin

Question 29

close range

Answer 29

less than 6 inches, GSR can be embedded around bullet hole, pattern small and dense, pattern increases w distance

Question 30

medium range

Answer 30

gun is 1.5-3 ft from target

Question 31

long distance

Answer 31

greater than 5 ft

Question 32

compression indentation

Answer 32

produced by pressing an object against softer surface

Question 33

sliding/ abrasion

Answer 33

when surfaces slide | scratches and striations

Question 34

cutting marks

Answer 34

along edge of surface as it is cut

Question 35

bullet wipe

Answer 35

The discolored area on the immediate edge of a bullet hole, caused by bullet lubricant, lead, smoke, bore debris, or possibly jacket material.