Firearms and Toolmarks Flashcards
How much was criminal use of firearms increased from 2009-2019?
81%
how many homicides involving firearms in 2020?
277
what percentage of homicides involve a firearm?
37.2
T/F: drug crime always involves weapons
false cause not always
what are commonly used illegal drugs in canada?
- MDMA
- acid (LSD)
- meth
- coke
- speed
- heroine
how many poppyseeds/grains of sand worth of fentanyl is lethal?
7 seeds or 32 grains of sand
T/F: there is another more lethal type of fentanyl. if true what is its name
true carfentanyl
what drug reverses effect of opioid overdose?
naloxone
what should you include in a drug scene examination?
- photographs
- fingerprinting of evidence
- drug seizures (done by drug unit member)
T/F: drugs are stored at forensic units
false
what are the types of firearms?
hand guns and long guns
what are the types of hand guns?
revolver and pistol
what is a pistol?
- handgun with a single barrel and chamber
- fires a chambered round
- extracts and ejects empty casing
- loads a new round with each trigger pull
what is a pistol?
- handgun with a cylinder that has multiple chambers
- when trigger is pulled, cylinder rotates around a central pin to align the next chamber with the firing pin
- one bullet per trigger pull
T/F: a single action handgun cocks then drops the hammer with the pull of a trigger.
false
how does a single action gun work?
hammer must be cocked manually then trigger pulled to fire the gun each time
define a double action handgun.
fired with one pull of the trigger which drops the hammer
what ammo is used for rifles and shotguns?
bullets and shells
what is the difference between ammo types in long guns?
shell: has a bunch of ball shaped projectiles called shot
T/F: shotguns have grooves and lands
false
what are the raised and lowered portions in rifling called?
lands and grooves
is a 10 gauge shotgun small barreled?
no
what is a repeating shotgun?
mechanical instrument to eject spent shot shell, load a new round and cock the hammer after round is fired
what three subtypes of repeating shotgun are there?
- pump
- bolt
- lever action
what are semi-automatic shotguns?
uses the force of gas during firing to eject the spent cartridge to load a new round and cock the hammer
define a break open action shotgun,
must be loaded each time its fired, trigger needs to be pulled each time
what is a repeating rifle?
has a mechanical instrument to eject spent cartridge, load a new round and cock the hammer after round is done
what are types of repeating rifles?
- pump
- bolt
- lever action
- semi-automatic
what is live ammunition referred to as?
cartridge not yet fired
what is included in ammunition cartridge cases?
primer, gunpowder, and a bullet
what might be recovered after a shot has been fired?
fired bullet and cartridge case
what primer is most common?
centre fire
what is on the base of a cartridge case?
manufacturers name and tradmark
how are cartridges measured?
metric (ie 9mm) or imperial (0.22 or 0.357)
how can you identify a firearm?
- serial number
- manufacturer
- type of firearm
- loaded/unloaded/chambered
- descriptive characteristics (accidental characteristics)
- semi-automatic vs. fully automatic
how do you link firearms to scenes?
- striations in fired bullet
- gunpowder residue pattern
- trajectory, ricochet, bullet holes
- fingerprints (rare)
- firing pin impressions
- ejector and extractor marks
- bullet damage to tissue
- dna
how long is GSR on hands?
within 8 hours of the incident
what is IBIS?
integrated ballistics identification system
what is the purpose of IBIS?
tool that enables comparisons and linkages that may exist amonst firearms cases submitted for examination
what is CIBIN?
canadian integrated ballistics identification network
what is the purpose of cibin?
assist police in linking crime scenes or crime scene items to firearms
who maintains CIBIN?
RCMP
what does penetrate mean ;)
to enter an object and stay in it
what does perforate mean?
to pass all the way through an object
what should be done in a shooting scene examination?
- document: notes, photos, sketch, etc.
- search
- suspects (swab hands, clothes, vehicles etc.)
- examine victim
- submit to CFS
T/F: you should treat all guns as unloaded
false
how should a gun exhibit be entered?
proving it is safe and the action open
how should you pick up a gun?
hold by trigger guard or barrel to not have any fingerprint alterations
where should you swab on a gun?
textured area of the grip and or the slide
T/F: during the manufacturing process most tools have unique microscopic characteristics
true
on a cut wire how can you tell a specific tool?
the class characteristics will mark the surfaces
what are the conclusions in examinations?
- identification
- inconclusive
- elimination
- unsuitable
how do you document toolmarks?
- notes
- photos
- casts of marks
what is the most common impression cast material?
mikrosil
