Gun Shot Residue Flashcards
what are the main components of GSR?
barium, lead, and antimony
T/F: you can find GSR on the shooters hands
true
What are points of interest for GSR?
hands, hair, face, large objects (ie cars), clothing etc.
Where is the Latent Forensic kit made? What does it include?
Canada by RCMP, Canadian forms (instructions for collection and lab submission forms)
T/F: you will always find all three barium, antimony and lead in GSR.
False, you may find a mixture of 2 or all three in unequal amounts.
What are characteristics of GSR?
Pb, Be, Sb
what is consistent with GSR?
Pb/Be, or Be/Sb, or Pb/Sb
what kind of components are analyzed in scanning electron microscopy and energy dispersive spectroscopy?
inorganic compounds
What is offence level (III)?
did the POI shoot the victim
what is activity level (II)?
did the POI discharge a firearm?
What is Source level (I)
is the trace arising from the POI hands GSR?
what are some environmental sources of GSR that are not from GSR?
Brake pads, fireworks, nail guns, matches and, exploded airbags
With the survey of GSR prevalence on clothing what offences did they use to examine the garments?
non-firearm offences
what percentage of garments contained Pb/Sb/Ba?
2%
what percentage of garments had no particles whatsoever?
50%
what is the probability of finding one 3-component particle on clothing by chance?
0.01
the initial discharge of of a firearm results in the _____ of GSR particles onto surfaces in near proximity
direct deposition.
GSR may be transfered to another surface by what?
a secondary transfer
what percentage of officers had at least one GSR particle present?
10%
in the simulated arrest situation being used to investigate GSR tansfer what was the probability of particle transfer
25%
how many GSR particles are typically found after firing a gun?
0-3000 (generally on the lower end)
what kind of gun will result in less characteristic GSR particles?
shot guns
for shot guns where are you likely to see GSR?
supporting hand, and in the crook of the supporting arm
where are you likely to find GSR from an automatic weapon?
both hands
T/F: Automatic rifles make more GSR than revolvers and pistols
false there will be less particles found for automatic weapons
how time sensitive is the GSR sample collection?
there will be rapid loss in the first few hours
T/F: the guns do not effect GSR persistance.
true
what types of material were used to assess the collection efficiency of gunshot residues?
cotton, worn cotton, leather, wool/vicose/acrylic
T/F it is more common to get characteristic paraticles on gun shot residue?
false
what kind of fabric has greater persistance of GSR than other fabrics?
leather
what fabric has the greatest shedability rate?
cotton
