SN Restoration
Firearms most common in what metal?
aluminum alloy, stainless steel, and steel
Naturally occurring: morphine, cocaine, marijuana
Semisynthetic: Heroin, LSD
Synthetic: Oxycodone, methamphetamine, PCP
What are some screening test for drug identification?
Visual analysis and microscopic examination
Accurate weighing/measuring sample, selecting representative sample to test
Presumptive tests - colour tests, microcrystalline tests, TLC, UV-spectrophotometry
What’s a key indicator of airbag deployment?
Talc particles
Lowest temperature at which a liquid gives off sufficient vapour to form a mixture with air to support combustion
Flashpoint of gasoline = -50oF
SN can be applied through three things?
Dot matrix, Laser engraving, Stamped.
Narcortic drugs are what and give examples
Analgesic/pain killing substance that relieves pain by depressing the action of the central nervous system
Examples of opioid drugs are morphine, heroin, codeine, oxycodone, hydrocodone, fentanyl
Marquis test
purple in presence of heroin, morphine and most opiate derivatives
orange/brown when mixed with amphetamines and methamphetamines
light pink in presence of PCP, orange-brown-purple for LSD
Describe the difference between the driver and passenger airbag.
Driver’s airbag circular from steering wheel and Stitching circular
Passenger airbag rectangular and Stitching straight
What pattern is a strong indicator of accelerant use at a fire scene?
Streamer trails
What process reveals stamped serial numbers through corrosion?
Acid etching
What are Hallucinogens? Give examples.
Drugs that cause marked alterations in normal thought processes, perceptions and moods.
Examples include marijuana, LSD, PCP, MDMA
Mandelin test
Cobalt thiocyanate/Scott’s test
turns olive green colour for amphetamines, blue-grey for heroin
test for cocaine; turns blueish colour
What would happen to a light filament if a significant accident occurred while the light was off?
The filament would exhibit a clean break because it would not be warm/heated. If the glass was broken then there would be oxides present on the filament
Flammable liquids always flow to lowest point.
True or False
True
How does acid etching help reveal serial numbers?
Etches deformed (compressed) metal faster, revealing imprint
What is Depressants? Examples?
Substance used to depress the functions of the central nervous system – meant to calm irritability and anxiety and induce sleep
Examples include alcohol, barbiturates, tranquilizers
Nitric acid test
secondary screening for confirmation of opiates and amphetamines;
yellow-light green indicates heroin
orange-red-yellow indicates morphine
orange only indicates amphetamines
What is a common burn source from airbag deployment?
What causes the "singe" pattern on clothing after airbag deployment?
Sodium azide upon explosion creates N2(g), Hot nitrogen gas fills airbag → burns on clothing or skin
Small dots from front of bag or large from back vent holes
Analysis of flammable residue is
GC because it is most sensitive and reliable
Describe the process of SN restoration?
Sand metal down with progressively finer sandpaper until metal is finely polished. Apply appropriate chemicals to react (corrode) the metal. The number impression will erode at a faster rate creating the etching pattern.
Stimulus is what? Examples?
A substance taken to increase alertness or activity, stimulate the central nervous system = uppers/speed
Examples include amphetamines, cocaine
Mecke’s test
test for heroin, MDMA; initially turns blue is indicative of MDMA,
yellow-green colour intensifies with prolonged agitation indicates heroin
What visual evidence indicates that a headlight was on at the time of an accident?
1. the filament may show signs of oxidation, such as discolouration or the formation of oxides, due to exposure to oxygen when the vacuum is broken.
2. The filament may also appear twisted, stretched, or melted, and glass can adhere to the filament as a result of the heat and impact.
3. Additionally, arc marks (localized burns or bright spots on the filament) are strong indicators that the filament was energized during the collision.
What indicates an accelerant may have been used?
Burn patterns on floor, streamers, intense localized burning