Midterm 3 Flashcards
Analysis of Flammable residues
Headspace Technique –
◦ Material placed in airtight container
◦ Heat container to release volatile residue
◦ Vapors pulled out of the top of container
◦ Vapor Concentration –
◦ Charcoal coated strip placed in container with
material
◦ Heated for a period of time
◦ Charcoal absorbs volatile residue
◦ Wash off volatile residue with CS2
Low Explosives
an explosive with a velocity
of detonation less than 1,000 meters per second
◦ Black powder – 75% potassium nitrate, 15%
charcoal, 10% sulfur
◦ Nitrocellulose
◦ Smokeless powder –nitrocellulose and nitroglycerin
◦ Chlorate mixtures
◦ Gas-air mixtures – 5.3% to 13.9% methane in air by
volume
High Explosives
an explosive with a velocity of detonation greater than 1,000 meters per second
Primary Explosive
a high explosive that is easily detonated by heat, shock, or friction ◦ Lead azide ◦ Lead styphnate ◦ Diazodinitropheno
Secondary Explosive
a high explosive that is
relatively insensitive to heat, shock, or
friction
◦ TNT (trinitotoluene)
◦ PETN (pentaerythritol tetranitrate)
◦ RDX (cyclotrimethylenetrinitramine)
◦ Tetryl (2,4,6-trinitrophenylmethylnitramine)
Ammonium nitrate
a strong oxidizer that is mixed with a fuel forming a stable explosive
◦ ANFO (ammonium nitrate fuel oil)
Explosives
Detonators - initiate explosion of high explosives
Blasting caps are most often used as detonators
Evidence of Explosives
ion mobility spectromemter microscopy color spot test fluorescent and magnetic chip added to commercial explosives Thin-Layer Chromatography (TLC) High-Performance Liquid Chromatography (HPLC) Gas Chromatography (GC) Infrared Spectroscopy X-ray diffraction
Gun structure
striker and barrel will leave marks
need to collect ejected cartridges to make sure find all projectiles
Nitrocellulose is known as guncotton. What is this explosive classified?
low Explosive
Gun Barrel Rifling are made by
hand, hammer forging or electrochemical etching
where to find gun shot residue
on suspect, victim or material that may have been in contact with gun
presence of gun shot residue ≠someone fired a gun
No, the person may have touched the gun soon after it was fired; the person may have been cleaning a gun
Rifling Characteristics
Caliber (size of bullet)
Number of lands and grooves
Direction of twist of the rifling
Widths of lands and grooves
What are the tool marks
Compression – a tool is pressed into a softer
material
Sliding – a tool slides across a surface
Cutting – combination of compression and
sliding
Drug Classification (3)
Natural Product – a drug that is derived
directly from a plant
Semi-Synthetic – a drug that is derived
indirectly from plant matter
Synthetic – a drug that is synthesized rather
than extracted from a plant
Acid drugs (b/c of OH groups)
GHB – gamma hydroxybutyric acid
GBL – gamma butyrolactone
Marijuana and Hashish
acidic Drugs - Steroid
naturally occurring lipid composed of four fused rings
Neurotransmitters – a substance in the body
that carries information from one nerve cell
to another
dopamine; serotonin ( by body)
amphetamine, methamphetamine (synthetic)
Alkaloid
opiate:
compound derived from or related to the extract of the unripe seed pods of the opium poppy morphine, codeine, MAM, Heroin, cocaine (not opiate)
Endorphin
Interact with receptors in the brain to reduce perception of pain and stress
Analgesic
Analgesic – alleviate pain;
such as aspirin, acetaminophen and ibuprofen
Depressant
Depressant – causes depression of central nervous system; such as alcohol, barbiturates and tranquilizers
Hallucinogen
Hallucinogen – causes changes in thoughtsand perception;
such as marijuana, LSD and mescaline
Narcotics
Narcotics – relieve pain and encourage sleep;
such as morphine, oxycodone and heroin
Stimulants
Stimulants – stimulates the central nervous system;
such as methamphetamine, cocaine and amphetamine
Drug Classification
Predator Drugs – used to incapacitate a victim (most likely narcotics/depressants)
Club Drugs - used by teenagers and young adults (hallucinogens and stimulants) at bars, nightclubs, concerts, and parties
Human Performance Drugs – drugs that improve or impair one’s performance (steroids, stimulants, or depressants)
Inhalants – drugs that are inhaled to produce their
desired effect
The Five P’s
Powders, plant matter, pills, precursors (chemicals or over the counter drugs that can be converted into regulated substances), paraphenalia
Cutting Agents
Diluents – material added to dilute a drug
that is pharmacologically inactive (baking soda, corn starch, salt, sugar)
Adulterants – material added to dilute a drug that is pharmacologically active
Impurities – substance other than the drug or analyte of interest (remains from the synthesis or extraction process)
GSR?
Gunshot Residue
1) Primer residues from the combustion of the cartridge priming mixture when the primer was struck by the firing pin
2) Residues resulting from the burning of the propellant
3) Material generated by the interaction of the bullet with the inside of the barrel
4) Unburned and partially burned powder
Nitrate Test
Modern “smokeless” gunpowder used in bullets today contains many nitrogen-containing compounds like nitrocellulose, nitroglycerin and trinitrotoluene (TNT) all of which give a positive for this test colorless to blue diphenylamine + nitrate + sulfuric acid
Nitrite test (greiss test)
orange color
lead test fro cartridge primer
sodium rhidozonate to pink(after lead) to dark blue(after HCL+lead)
antimony test
colorless to yellow orange
copper test from lead free bullets
dithiooxamide to olive green
When no GSR is found around a bullet hole, it can mean several things.
- The firearm was at a distance far enough away that the residues did not reach the garment.
- An intervening object between the firearm and garment prevented the residues from reaching the garment.
- Gunshot residues were removed through severe handling, heavy bleeding, or by laundering.
Drug testing - Presumptive color test
The Marquis Test – turns orange-red in the
presence of amphetamine and
methamphetamine, turns violet in the
presence of morphine
Ehrlich’s Test – turns purple in presence of
LSD and indole alkaloids
Liebermann Test – changes color in the
presence of phenols and amines
Simon Test – distinguishes between
amphetamine and methamphetamine
Duquenois-Levine Test – test for marijuana
Modes of Ingestion
Injection into the tissue under the skin (subcutaneous)
Injection into a vein (intravenous)
Absorption through the skin (dermal)
Injection into muscle (intramuscular)
Inhalation or aspiration (inhalation of liquid)
Ingestion into the stomach
Dissolution under the tongue (sublingual)
Absorption through the mucus membrane of the nose
Absorption through the eyes
Metabolism
Xenobiotic – a substance that is not normally ingested or that is present but in much smaller quantities than the dosage in question
Metabolite – products of metabolic reactions and conversions
Elimination
Liquid metabolites released in urine or sweat
Gaseous metabolites exhaled
Excretion can also be in feces, tears, saliva,
hair, nails and skin
dosage consideration Ed50 and LD50
ED50 – the dose that will lead to the desired response in 50% of the test population (median effective dose)
LD50 – the dose that causes death in 50% of the test population (median lethal dose)
Endogenous vs exogenous
Endogenous – a substance, compound,
element, or material that is naturally present
in the body
Exogenous - a substance, compound,
element, or material that is not naturally
present in the body (indicate exposure to something)
Antibodies
Polyclonal antibodies – a series of antibodies are
produced responding to a variety of different sites
on the antigen
Monoclonal antibodies – a collection of identical
antibodies that interact with a single antigen site
EMIT
Enzyme Multiplied Immunoassay Technique
the minimum temperature at which a liquid fuel produces enough vapor to burn
Flash point -the minimum temperature at which a liquid fuel produces enough vapor to burn
the decomposition of solid organic matter by heat
Pyrolysis – the decomposition of solid organic matter by heat
combustion on the surface
of a solid fuel in the absence of heat high enough
to pyrolyze the fuel
Glowing combustion – combustion on the surface
of a solid fuel in the absence of heat high enough
to pyrolyze the fuel
a fire caused by a
natural heat producing source in the presence
of sufficient air and fuel
Spontaneous Combustion – a fire caused by a
natural heat producing source in the presence
of sufficient air and fuel
requires fuel, oxygen and heat (initiate combustion and sustain relation)
NIBIN
National Integrated Ballistics Information Network
