Ballistics

Question 1

Explain why ballistic science is important?

Answer 1

Firearms were used in:
69% of the US murders
40% of robberies
21.6% of aggravated assaults

Question 2

Handguns can be held and fired with ______. They are divided into ___ categories. Name them

Answer 2

one hand 
3
revolvers 
semiautomatic pistols 
machine pistols

Question 3

• Handguns
  Revolvers have a _____ to hold bullets and short _____.
  One pull of the trigger = ___ shot.
  Shell casting remains in the ______ after firing.

Answer 3

cylinder cartridges
1
cylinder

Question 4

• Handguns
  Semiautomatic pistols have a ____ or a ____.
  Each shot = __ shot.
  empty shells are automatically _____.

Answer 4

magazine or clip
1
removed

Question 5

• Handguns
  Machine pistols, automatic. It fires ______ (as long as ______).
  ___ similar to semiautomatic pistols.

Answer 5

repeatedly
there is ammunition
clip

Question 6

Rifles often use a ____ or a sliding ___ to eject the spent cartridge. They can be ___ or _____.

Answer 6

lever blot

automatic or semiautomatic

Question 7

Shotguns don’t fire ____, but _____ filled with groups of ___. Those spread out in ____ pattern and the shot spread about an inch for each ___ feet of travel.

Answer 7

bullets
shells
pellets
circular
3

Question 8

Shotguns have no ___ in the barrel, so no ____ marks.

Answer 8

grroves

identifying

Question 9

Intact bullets are ____ found, so bullets often considered _______.

Answer 9

rarely

trace evidence

Question 10

How can we find the manufacturer of the gun?

Answer 10

chemical and physical composition of the bullet. powder in the bullets.

Question 11

What information can be found with a recovered bullet?

Answer 11

1- a type of gun
2- trace evidence: paint, fibers
3- DNA flesh and blood.

Question 12

What are the 3 limits of ballistic science when it comes to recovered bullets?

Answer 12

1- severely deformed
2- too small
3- damaged during recovery

Question 13

____ bullets are soft, deform and fragment as they reach the target and they cause ____ damage.

Answer 13

Lead

tissue

Question 14

Lead ___ bullets are different than Lead bullets because they are mixed with ____ and ____. They deform and fragment (more/less) than lead bullets.
Also, they have (more/less) penetrability.

Answer 14

alloy
tin antimony
less
more

Question 15

Semijacketed bullets have a thin layer of ____ on the side.

They ____ and fragment upon impact.

Answer 15

brass

expand

Question 16

Fully jacketed bullets are ____ covered with brass. They have a ___ penetrating power. They can penetrate body armour which is why they are called ______. Their jacket is made of ___, ____ and other synthetics.

Answer 16

completely
greater
cop killer
Teflon, nylon

Question 17

How do we calculate the calibre of a gun?

How do we calculate the gauge of a gun?

Answer 17

1- measurement of the internal diameter of the barrel. in inches or mm
2- number of balls that can fit in the barrel diameter - inverse relation.

Question 18

The shell casing is the part of the bullet that ________.
It retains marks such as:
impression left by the ______ (centre-fire or rim-fire)
_____ pattern
_________
_____ or ejector marks.

Answer 18

remains after the powder explodes and the bullet is gone. 
firing pin
breechblock
headstamps
extractor

Question 19

The rifling pattern helps link a ____ to a _____.

Answer 19

bullet

gun/gun type

Question 20

Spiral grooves are inside the _____ and make the bullet ____. They make the shot more _____ and create marking that can be used in forensic.

Answer 20

barrel
spin
precise

Question 21

depending on the manufaturer:

the____ of the grooves, the _____ of the lands, the direction (______/_______), and the ____ of the twist.

Answer 21

depth
width
clockwise/counterclock
degree

Question 22

What are the three things that can link the bullet to a gun (simply with the rifling pattern)?

Answer 22

1- lands and grooves
2- twists
3- striations

Question 23

What are the 3 limits of rifling patterns?

Answer 23

1- silencer
2- rifling patterns vary from barrel to barrel
3- when using a gun a lot, the grooves and the lands wear down.

Question 24

What are the four steps to individualizing striations?

Answer 24

1- obtain intact bullet
2- compare the lab fired bullet + crime scene bullet
3- see if there is a match with a comparison microscope
4- identify or not the perpetrator

Question 25

How many striations (consecutive) are necessary to have a match?

Answer 25

3

Question 26

What is a gunshot residue and when is it used?

Answer 26

powder that explodes when the shot is fired.

When no gun, no bullets, no shell casing.

Question 27

Where can GSR be found? 8

Answer 27

shooters hand 
arm 
clothing 
face
hair
walls
furniture 
victims clothing

Question 28

____ and ____ can change the pattern or lessen the spread of the GSR cloud.

Answer 28

wind and rain

Question 29

GSR are visible on ______ clothing, but needs further testing on _____.

Answer 29

light-colored

dark

Question 30

Firing distance can be estimated when GSR is found on the ____ of a victim. Only if there was no _____ in between.

Answer 30

wound

clothing

Question 31

Firing distance can also be estimated if a pattern of GSR is found on the ______. The farther the distance, the ____ the spread. After a certain distance, ____ residue is found.

Answer 31

clothing
wider
no

Question 32

People who get shot rarely die ______. Also, they will probably die of _____ or _____.

Answer 32

immediatly
exsanguination
infection

Question 33

The character of the shot depends on: 4

Answer 33

1- distance between shooter and victim
2- caliber and velocity f the bullet
3- angle at which the bullet enters the body
4- whether the bullet remains or exits the body

Question 34

When the bullet hits the victim, it creates an ____ wound and sometimes an ____ wound.

Answer 34

entry

exit

Question 35

the bullet often (remains in/exits)____ the victim.

determining the entry and exit wound in crucial in _____.

Answer 35

remains in

reconstructing the crime scene.

Question 36

Exit wounds are typically ____ because it gets ____ inside the body and ____ its ways out of the tissues.

Answer 36

larger
derformed
tears

Question 37

____ bullets are easily deformed and create more damage as the bullet tries to exit the body.

Answer 37

softer

Question 38

If the victim wears ___ clothing or is standing ___ a wall, the skin is ___ likely to tear. And the exit wound can look like _____.

Answer 38

tight
against
less
an entry wound

Question 39

A shotgun creates ___ entry wounds, creating a ___ pattern which can help determine the ___ between the victim and the shooter.

Answer 39

multiple
shot
distance

Question 40

Muzzle 2 feet or more creates:
Muzzle 6 inches to 2 feet creates: because?
muzzle less than 6 inches creates:
muzzle pressed against victim:

Answer 40

buising in a halo around the hole
speckles, gunpowder
area charring around the hole
ripping around the whole