Midterm 3

Question 1

Analysis of Flammable residues

Answer 1

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

Question 2

Low Explosives

Answer 2

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

Question 3

High Explosives

Answer 3

an explosive with a velocity of detonation greater than 1,000 meters per second

Question 4

Primary Explosive

Answer 4

a high explosive that is
easily detonated by heat, shock, or friction
◦ Lead azide
◦ Lead styphnate
◦ Diazodinitropheno

Question 5

Secondary Explosive

Answer 5

a high explosive that is
relatively insensitive to heat, shock, or
friction
◦ TNT (trinitotoluene)
◦ PETN (pentaerythritol tetranitrate)
◦ RDX (cyclotrimethylenetrinitramine)
◦ Tetryl (2,4,6-trinitrophenylmethylnitramine)

Question 6

Ammonium nitrate

Answer 6

a strong oxidizer that is mixed with a fuel forming a stable explosive
◦ ANFO (ammonium nitrate fuel oil)

Question 7

Explosives

Answer 7

Detonators - initiate explosion of high explosives

Blasting caps are most often used as detonators

Question 8

Evidence of Explosives

Answer 8

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

Question 9

Gun structure

Answer 9

striker and barrel will leave marks

need to collect ejected cartridges to make sure find all projectiles

Question 10

Nitrocellulose is known as guncotton. What is this explosive classified?

Answer 10

low Explosive

Question 11

Gun Barrel Rifling are made by

Answer 11

hand, hammer forging or electrochemical etching

Question 12

where to find gun shot residue

Answer 12

on suspect, victim or material that may have been in contact with gun

Question 13

presence of gun shot residue ≠someone fired a gun

Answer 13

No, the person may have touched the gun soon after it was fired; the person may have been cleaning a gun

Question 14

Rifling Characteristics

Answer 14

 Caliber (size of bullet)
 Number of lands and grooves
 Direction of twist of the rifling
 Widths of lands and grooves

Question 15

What are the tool marks

Answer 15

 Compression – a tool is pressed into a softer
material
 Sliding – a tool slides across a surface
 Cutting – combination of compression and
sliding

Question 16

Drug Classification (3)

Answer 16

 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

Question 17

Acid drugs (b/c of OH groups)

Answer 17

GHB – gamma hydroxybutyric acid
GBL – gamma butyrolactone
Marijuana and Hashish

Question 18

acidic Drugs - Steroid

Answer 18

naturally occurring lipid composed of four fused rings

Question 19

Neurotransmitters – a substance in the body
that carries information from one nerve cell
to another

Answer 19

dopamine; serotonin ( by body)

amphetamine, methamphetamine (synthetic)

Question 20

Alkaloid

Answer 20

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)

Question 21

Endorphin

Answer 21

Interact with receptors in the brain to reduce perception of pain and stress

Question 22

Analgesic

Answer 22

Analgesic – alleviate pain;

such as aspirin, acetaminophen and ibuprofen

Question 23

Depressant

Answer 23

Depressant – causes depression of central nervous system; such as alcohol, barbiturates and tranquilizers

Question 24

Hallucinogen

Answer 24

Hallucinogen – causes changes in thoughtsand perception;

such as marijuana, LSD and mescaline

Question 25

Narcotics

Answer 25

Narcotics – relieve pain and encourage sleep;

such as morphine, oxycodone and heroin

Question 26

Stimulants

Answer 26

Stimulants – stimulates the central nervous system;

such as methamphetamine, cocaine and amphetamine

Question 27

Drug Classification

Answer 27

 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

Question 28

The Five P’s

Answer 28

Powders, plant matter, pills, precursors (chemicals or over the counter drugs that can be converted into regulated substances), paraphenalia

Question 29

Cutting Agents

Answer 29

 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)

Question 30

GSR?

Answer 30

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

Question 31

Nitrate Test

Answer 31

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

Question 32

Nitrite test (greiss test)

Answer 32

orange color

Question 33

lead test fro cartridge primer

Answer 33

sodium rhidozonate to pink(after lead) to dark blue(after HCL+lead)

Question 34

antimony test

Answer 34

colorless to yellow orange

Question 35

copper test from lead free bullets

Answer 35

dithiooxamide to olive green

Question 36

When no GSR is found around a bullet hole, it can mean several things.

Answer 36

1. The firearm was at a distance far enough away that the residues did not reach the garment.
2. An intervening object between the firearm and garment prevented the residues from reaching the garment.
3. Gunshot residues were removed through severe handling, heavy bleeding, or by laundering.

Question 37

Drug testing - Presumptive color test

Answer 37

 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

Question 38

 Modes of Ingestion

Answer 38

 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

Question 39

Metabolism

Answer 39

 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

Question 40

Elimination

Answer 40

 Liquid metabolites released in urine or sweat
 Gaseous metabolites exhaled
 Excretion can also be in feces, tears, saliva,
hair, nails and skin

Question 41

dosage consideration Ed50 and LD50

Answer 41

 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)

Question 42

Endogenous vs exogenous

Answer 42

 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)

Question 43

Antibodies

Answer 43

 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

Question 44

EMIT

Answer 44

Enzyme Multiplied Immunoassay Technique

Question 45

the minimum temperature at which a liquid fuel produces enough vapor to burn

Answer 45

Flash point -the minimum temperature at which a liquid fuel produces enough vapor to burn

Question 46

the decomposition of solid organic matter by heat

Answer 46

Pyrolysis – the decomposition of solid organic matter by heat

Question 47

combustion on the surface
of a solid fuel in the absence of heat high enough
to pyrolyze the fuel

Answer 47

Glowing combustion – combustion on the surface
of a solid fuel in the absence of heat high enough
to pyrolyze the fuel

Question 48

a fire caused by a
natural heat producing source in the presence
of sufficient air and fuel

Answer 48

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)

Question 49

NIBIN

Answer 49

National Integrated Ballistics Information Network