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Introduction to
Forensic
Science and
Criminalistics
Chapter 12
Prepared by
Peter Bilous
Eastern Washington
University
Bell Work for Friday, January 4


Pick up the notes up front (2 sided!)
We will finish watching CSI and take
notes on Drugs and Toxicology
© 2007 The McGraw-Hill Companies, all rights reserved.
Drugs and Drug Analysis and
Forensic Toxicology
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Nature of Drugs and Drug Abuse
Major Classes of Abused Drugs
Controlled Substance Laws
Analysis of Controlled Substances in the
Forensic Laboratory
Forensic Toxicology –
Antemortem and Postmortem
Alcohol and Drugs and
Driving
© 2007 The McGraw-Hill Companies, all rights reserved.
I. Nature of Drugs and Drug Abuse
1. Working Definition of a Drug:
 A drug is any substance that produces
physiological or psychological change within a
short period of time after ingestion and from
a easily ingested dose
2. Nature of Drug Dependence:
 Drug dependence is when an individual
becomes strongly attached to a drug
 Dependency is subdivided into two
categories: physiological and psychological
© 2007 The McGraw-Hill Companies, all rights reserved.
I. Nature of Drugs and Drug Abuse
2a. Physiological Dependence:
 With physiological dependence, there is a
need by the body to have the drug present
 A person experiences sickness if they stop
taking the drug
2b. Psychological Dependence:
 A person develops an uncontrollable “craving”
(mental or emotional need) for a drug
 The craving is a desperate need to continue
© 2007 The McGraw-Hill Companies, all rights reserved.
II. Major Classes of Abused Drugs
Drugs of abuse can be divided into six basic categories
• Narcotic Drugs – taken to dull pain (analgesic)
• Stimulants – taken to increase mental and physical
energy
• Hallucinogens – taken to change one’s mental state
• Depressants, Hypnotics, & Tranquilizers – taken to dull
one’s senses, to reduce anxiety, or induce sleep
• Club Drugs – taken to enhance one’s enjoyment of a
party or other social activities
• Performance Enhancing Drugs – taken to build
muscles, endurance, or enhance athletic performance
© 2007 The McGraw-Hill Companies, all rights reserved.
II. Major Classes of Abused Drugs
1. Opiates or Narcotic Drugs:
 Narcotic drugs are painkillers (analgesics)
 Morphine is a narcotic and the primary active
drug in opium, the dried sap of the opium poppy
plant
 Opium can be smoked directly or
chemically processed to isolate
pure morphine
 All natural and drug compounds
derived from opium are known as
opiates
© 2007 The McGraw-Hill Companies, all rights reserved.
II. Major Classes of Abused Drugs
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Opiates are psychologically addictive drugs, with
withdrawal causing severe physiological symptoms
Codeine is the second most plentiful chemical
component of opium, used as a strong painkiller and
cough suppressant
Heroin, a derivative of
morphine is at least as
addictive as morphine
Synthetic painkillers include
Darvon & Demerol
© 2007 The McGraw-Hill Companies, all rights reserved.
How the Drug Works
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Depresses the CNS, reducing the
conduction of nerve impulses to and
from the brain
Pain impulses are reduced to
manage pain
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Symptoms
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extreme sleepiness
Droopy eyelids
Depressed (slow) reflexes
Euphoria (intense feeling of happiness/joy)
Dry mouth
Facial, extremities itching
Low, raspy speech
Signs of needle puncture (track marks) may
be present
Eyes are usually normal in movement, but
pupils will be severely constricted (small)
© 2007 The McGraw-Hill Companies, all rights reserved.
Problems with use/abuse
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Highly physiologically addictive
To obtain same level of “High”, users must
continually increase dosage
May cause hearing loss (Rush Limbaugh)
In cases of heroin, the user never knows
what it may be cut with (quinine, starch,
lactose, Novocain, mannitol (sugar))
Increased risk of HIV and or Hepatitis
infection (needle use)
© 2007 The McGraw-Hill Companies, all rights reserved.
Withdrawal Symptoms
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Nausea
Vomiting
Goosebumps
Sweating
Restlessness
Tremors
Lacrimation (eyes tearing)
Nasal congestion
Yawning
Changes in heart rate and blood pressure
Abdominal pain, muscle pain
Heat/Cold flashes
© 2007 The McGraw-Hill Companies, all rights reserved.
Forensic Tests
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Marquis Color Test – reagent turns purple
in presence of heroin and morphine and
most other opiates
Microcrystalline test – reagent is placed on
a slide containing small amount of the
drug, a reaction occurs and crystals form,
each type of drug has a specific crystalline
shape.
GC/Mass Spec. – chemical compositions
can be determined from analysis
© 2007 The McGraw-Hill Companies, all rights reserved.
VI. Alcohol and Drugs and Driving
Driving While Impaired by Alcohol:
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Alcohol is one of the easiest substances for
toxicologists to find in the body fluids, due to the
high dose and its chemical volatility
There is a good correlation between the amount of
alcohol in the blood and the level of impairment
Laws define the level of alcohol above which a
person would be considered impaired for the
purpose of operating a motor vehicle
Most states have defined the limit to be 0.08% w/v
(80 mg ethanol/100 ml of blood)
© 2007 The McGraw-Hill Companies, all rights reserved.
VI. Alcohol and Drugs and Driving
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In the field, alcohol levels are determined by
capturing a known volume of a person’s breath
using the Breathalyzer or Intoxilyzer
instruments
Alcohol levels in the breath can be correlated to
levels in the blood
In the lab, blood samples
are subjected to alcohol
determinations using the
GC
© 2007 The McGraw-Hill Companies, all rights reserved.
VI. Alcohol and Drugs and Driving
Other Drugs and Driving:
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All states have laws against driving while
impaired by drugs besides alcohol
Charges are supported primarily by behavioral
observations, but laboratory analysis showing a
significant level of a drug is almost always
required for successful prosecution
Prohibited levels for each drug have not been
developed and placed into state laws as with
alcohol
© 2007 The McGraw-Hill Companies, all rights reserved.
How the drug works
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Depresses the CNS (central nervous
system), particularly the brain
Absorbed from stomach and
intestines into the bloodstream,
where it travels to the brain
Depending upon a combination of
factors, maximum blood-alcohol
content may not be reached until 2-3
hrs after consumption
© 2007 The McGraw-Hill Companies, all rights reserved.
Effects on the brain
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The forebrain reacts first (area controlling
judgment) – lowers inhibitions, feeling of
warmth, happiness
Later central and rear portions of brain are
effected – loss of coordination, slurred
speech, impaired memory, slowed reflexes
The last area effected is the medulla which
regulates heart rate and respirations
© 2007 The McGraw-Hill Companies, all rights reserved.
Symptoms of effect
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Uninhibited behaviors
Uncoordinated
Drowsy, sluggish
Disoriented
Thick, slurred speech
Loss of consciousness
Trouble with visual tracking (eye jerking
horizontally, maybe vertically), pupil size
usually normal
© 2007 The McGraw-Hill Companies, all rights reserved.
Problems with use/abuse
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Psychologically and physiologically
addictive
Damages brain, liver - permanently
Severe binging can lead to poor
judgment
• Drunk driving, unprotected sex, etc.
• Memory impaired
© 2007 The McGraw-Hill Companies, all rights reserved.
Signs of withdrawal
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Tremors
Sweating
Restlessness
Inability to concentrate
Nervousness
Pain
© 2007 The McGraw-Hill Companies, all rights reserved.
Forensic Tests
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Breathalyzer test – subject exhales
into tube and alcohol content is read
Blood test – usually used in
conjunction with breathalyzer
Field sobriety test – eye tracking,
balance and coordination tests
determine ability to track and divide
attention
© 2007 The McGraw-Hill Companies, all rights reserved.
Barbiturates
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Downers
Amobarbital
Secobarbital
Phenobarbital
Pentobarbital
Butabarbital
Yellow jackets, Reds, Blue Devils
© 2007 The McGraw-Hill Companies, all rights reserved.
II. Major Classes of Abused Drugs
Depressants, Hypnotics, & Tranquilizers:
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Alcohol, a depressant, is the most abused drug in the
Western world
Barbiturates are highly physiologically active
depressants, resulting in a physical & mental state similar
to alcohol-induced intoxication
Valium, a benzodiazepine, is a tranquilizer
drug designed to relieve anxiety
Rohypnol or “roofies” is a benzodiazepine
and a major drug of abuse at raves and
the club scene
© 2007 The McGraw-Hill Companies, all rights reserved.
How the drug works
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Taken orally, enters the blood
stream from the small intestine
Relax the body and muscles
Creates feeling of well being
Produces sleep
© 2007 The McGraw-Hill Companies, all rights reserved.
Symptoms of Effect
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Sleepiness
Euphoria
Lowered heart rate and respiration
Uncoordination
© 2007 The McGraw-Hill Companies, all rights reserved.
Problems with use/abuse
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Extremely physiologically addictive
when taken in amounts larger than
the prescribed amounts
Physical withdrawal is extremely
severe and must be done under close
medical supervision
© 2007 The McGraw-Hill Companies, all rights reserved.
Symptoms of Withdrawal
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Insomnia
Severe muscle spasms
Delirium
Convulsions (severe)
Death
© 2007 The McGraw-Hill Companies, all rights reserved.
Forensic Tests
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Dillie-Koppanyi Color test – reagent
turns violet-blue in presence of
barbiturates
Microcrystalline tests
Gas Chromatography
© 2007 The McGraw-Hill Companies, all rights reserved.
Tranquilizers
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Drugs that produce a feeling of relaxed
tranquility without the impairment of
higher thinking skills or the inducement of
sleep
Reserpine
Chlorpromazine
Meprobromate (Miltown)
Chlordiazepoxide (Librium)
Diazepam (Valium)
Xanax, Zoloft
© 2007 The McGraw-Hill Companies, all rights reserved.
How the drug works
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Similar to barbiturates and other
depressants
Relaxes without impairment of
thinking or production of sleep
© 2007 The McGraw-Hill Companies, all rights reserved.
Problems with use/abuse
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Very addictive (psychological and
physiological) with high levels of
usage
Regulates mood so that there is no
up or down
Impairs sexual function (due to
regulation of mood)
Changes may be long lasting after
cessation
© 2007 The McGraw-Hill Companies, all rights reserved.
Withdrawal Symptoms
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Similar to other depressants
Need to feel happy, normal
© 2007 The McGraw-Hill Companies, all rights reserved.
Forensic Tests
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Microcrystalline Tests
Gas Chromatography
© 2007 The McGraw-Hill Companies, all rights reserved.
II. Major Classes of Abused Drugs
Hallucinogens:
 Are taken to cause a significantly altered mental
state, often including hallucinations
 Marijuana is one of the oldest
 The physiologically active ingredients are known
as cannabinoids, found in the resinous leaf
coating of Cannabis sativa
 The most active cannabinoid
is THC
(Tetrahydrocannabinol)
© 2007 The McGraw-Hill Companies, all rights reserved.
II. Major Classes of Abused Drugs
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Hashish is another form of marijuana,
traditionally a more potent form, made from
the flowering tops of the plant
Hash oil is made by taking the plant material
and cooking it with a solvent to remove the
plant resin
The solvent is then evaporated leaving a thick
oily material which is almost pure resin
The concentrated hash oil can be mixed with
tobacco or other vegetable material
© 2007 The McGraw-Hill Companies, all rights reserved.
II. Major Classes of Abused Drugs
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LSD is an extremely potent hallucinogen
The normal dose is only 30-50 micrograms
Causes visual hallucinations, brilliant colors,
and the perception that one is wise
PCP or “angel dust” is another popular
hallucinogen
PCP is fairly simple to
make, with the vast
majority made in
clandestine labs
© 2007 The McGraw-Hill Companies, all rights reserved.
II. Major Classes of Abused Drugs
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Naturally occurring hallucinogens include peyote,
the bud of a particular cactus
The main active ingredient in peyote is
“mescaline”
Magic mushrooms are mushrooms of the genus
Psilocybe, which
contains two active
components,
psilocin and
psilocybin
© 2007 The McGraw-Hill Companies, all rights reserved.
Hallucinogens (except
Marijuana)
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Drugs that cause marked changes in
normal thought processes, perceptions
and moods
LSD – lysergic acid diethylamide
STP – dimethoxymethylamphetamine
DMT – dimethyltryptamine
PCP – phenylcyclidine, mescaline
Psilocybin – Toxin produced by poisonous
mushrooms “shrooms”
MDMA –
Methylenedioxymethamphetamine
“ecstacy”
© 2007 The McGraw-Hill Companies, all rights reserved.
How the drug works
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Causes hallucinations
Taken orally, user experiences feelings of
strength or invincibility, along with a
sense of detachment (PCP)
All hallucinogens change neural pathways
so that brain impulses travel through
different areas of the brain than they
would usually.
Many effect levels of seratonin in brain,
chemical that regulates mood, causing the
user to feel good or happy.
© 2007 The McGraw-Hill Companies, all rights reserved.
Symptoms of effect
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Hallucinations
Dazed appearance
Body tremors
Incoordination
Sweating
Disorientation
Paranoia
Difficulty in speech
Nausea
Pupils usually noticeably dilated (Popped)
© 2007 The McGraw-Hill Companies, all rights reserved.
Problems with use/abuse
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Small amounts are extremely potent
Body stores in fatty tissues (lining of
nerves) can lead to flashbacks as
chemical is re-released into the body
Mind can be permanently put into
psychosis (mental illness)
Many times, feelings of anxiety and
tension accompany the hallucinations
(Bad Trips)
LSD may cause chromosomal damage
in gametes (egg and sperm cells of
users)
© 2007 The McGraw-Hill Companies, all rights reserved.
Other Problems
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Ecstasy causes grinding of teeth (look for
use of pacifiers), may cause lesions in the
tongue or mouth
Many users of PCP (angel dust) will
demonstrate schizophrenic behavior after
drug is removed
Often triggers abnormal fears, depression,
feelings of isolation, suicidal tendencies
Audio and visual hallucinations can cause
severe paranoia and tendency to violence
© 2007 The McGraw-Hill Companies, all rights reserved.
Withdrawal Symptoms
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Psychologically addictive – need it to
feel “normal” or happy
Low seratonin levels cause severe
depression
© 2007 The McGraw-Hill Companies, all rights reserved.
Forensic Tests
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Van Urk Color Test – reagent turns
blue-purple in presence of LSD
Gas Chromatography
Infra Red Spectrometry
© 2007 The McGraw-Hill Companies, all rights reserved.
Want to see what its like??
http://www.youtube.
com/watch?v=fVaLdd
nlafc
© 2007 The McGraw-Hill Companies, all rights reserved.
Inhalants
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Glue Sniffing
Whip-its
Inhalation of volatile solvents
Huffing
http://abcnews.go.com
/Blotter/dangerous-teencraze-whip-makingcomeback/story?id=160
06130
© 2007 The McGraw-Hill Companies, all rights reserved.
How the drug works
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CNS Depressant
Chemicals like toluene, freon,
naphtha, methyl ethyl ketone,
gasoline, trichloroethylene
Slows down the brain and reflexes
Slow heart rate, breathing and brain
activity
© 2007 The McGraw-Hill Companies, all rights reserved.
Symptoms
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Feeling of exhilaration, euphoria
Slurred speech
Impaired judgment
Double vision
Drowsiness
Residue on hands and clothes
Stupor (Severe DUH symptoms)
Eyes have problems tracking horizontally,
sometimes vertically
© 2007 The McGraw-Hill Companies, all rights reserved.
Problems with use/abuse
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Physiologically and psychologically
addictive
Danger of heart, lung, liver and brain
damage
Can result in suffocation and death
Seizures
Can cause brain lesions from solvent use
May dissolve membranes in the nasal
passage (slow loss of nasal cartilage)
Most chemicals are carcinogenic
© 2007 The McGraw-Hill Companies, all rights reserved.
Withdrawal Symptoms
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Headaches
Depression
Seizures
© 2007 The McGraw-Hill Companies, all rights reserved.
Forensic Tests
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Field sobriety tests
Look for residues on hands, face and
clothes
Look for chemical others
Redness of eye and nasal
membranes
© 2007 The McGraw-Hill Companies, all rights reserved.
Marijuana
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Varying forms of the plant cannabis sativa
Contains chemical – tetrahydrocannabinol
(THC)
May be in plant form, or dried or liquid
resin
Sinsemilla – potent form made from
female plant buds – high in THC resin
Hashish – resin only - high in THC – may
be in sticky solid or liquid form
© 2007 The McGraw-Hill Companies, all rights reserved.
How the drug works
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Smoked or ingested
In the brain, THC connects to specific sites
called cannabinoid receptors on nerve
cells and influences the activity of those
cells. Some brain areas have many
cannabinoid receptors; others have few or
none. Many cannabinoid receptors are
found in the parts of the brain that
influence pleasure, memory, thought,
concentration, sensory and time
perception, and coordinated
movement(5).
© 2007 The McGraw-Hill Companies, all rights reserved.
Symptoms of Effect
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Inability to divide attention, perform 2
tasks at once
Bloodshot eyes
Body tremors
Acrid odor
Disorientation
Relaxed inhibitions
Pupils slightly dilated
Paranoia
Impaired short term memory
© 2007 The McGraw-Hill Companies, all rights reserved.
Problems with use/abuse
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Causes cancer (more carcinogens than
tobacco – 5x as much)
Tolerance occurs easily (have to have more
and more to get high)
Physiologically and psychologically addictive
Bronchitis, more frequent chest colds
Suppresses immune system
Increases heart rate and blood pressure
Can trigger seizures in epileptics
Distortions in perception of the senses
Trouble with thinking and problem solving
© 2007 The McGraw-Hill Companies, all rights reserved.
Withdrawal Symptoms
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Depression
Restlessness
Loss of appetite
Insomnia
Weight loss
Shaky hands
© 2007 The McGraw-Hill Companies, all rights reserved.
Forensic Tests
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Field Sobriety tests
Drug Dogs
Duquenois-Levine Color test – chloroform
layer will turn purple when reagents are
added to suspect vegetation or resin.
Microscopic evaluations of structures –
crysolithic hairs on the upper side of the
leaf
Thin layer chromatography - TLC
© 2007 The McGraw-Hill Companies, all rights reserved.
II. Major Classes of Abused Drugs
Stimulants:
 Stimulants are taken to make one feel more
energetic, strong, or awake
 Amphetamine, methamphetamine, and cocaine are
examples of abused stimulants
 Methamphetamine is the drug most commonly
produced in clandestine labs
© 2007 The McGraw-Hill Companies, all rights reserved.
Stimulants (Cocaine)
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Cocaine
Crack
Caffeine
Nicotine
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How the Drug Works
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Accelerates heart rate and
respiration
Raises blood pressure
Speeds up or over-stimulates other
systems
Stimulates or Speeds up the CNS
Can act as an anesthetic
© 2007 The McGraw-Hill Companies, all rights reserved.
Symptoms
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Euphoria –caused by a rush of
neurochemicals in the pleasure centers of
the brain (Dopamine)
Restlessness
Exaggerated reflexes
Loss of appetite
Grinding teeth
Irritated nasal mucosa (if snorted)
Pupils noticeably dilated
Extremely excited, talkative
© 2007 The McGraw-Hill Companies, all rights reserved.
Problems with use/abuse
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Highly addictive (physiological and
psychological)
Can cause heart attack, seizures and
death
Gives user misplaced feelings of
being able to perform well or more
effectively – often the opposite is
true
© 2007 The McGraw-Hill Companies, all rights reserved.
Withdrawal Symptoms
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Restlessness
Severe Depression
Severe Cravings – users will do
anything to get more
© 2007 The McGraw-Hill Companies, all rights reserved.
Forensic Tests
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Microcrystalline test
Scott Color Test – reagent will turn
from blue to pink and back to blue in
the chloroform layer if cocaine is
present.
GC/ Mass Spec.
© 2007 The McGraw-Hill Companies, all rights reserved.
II. Major Classes of Abused Drugs
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Cocaine is a very powerful stimulant and
is enormously psychologically addicting
Cocaine hydrochloride is usually inhaled
through the nose
Cocaine in its free
base form, “crack”,
is vaporized by heat
in a pipe and inhaled
into the lungs
© 2007 The McGraw-Hill Companies, all rights reserved.
Stimulants (amphetamines)
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Methamphetamine
Uppers
Speed
Ephedra
Crank
Crystal Meth
Ice
© 2007 The McGraw-Hill Companies, all rights reserved.
How the drug works
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Increased alertness or activity by
stimulating the CNS
Speeds up all processes in the body
May be injected, snorted or ingested
© 2007 The McGraw-Hill Companies, all rights reserved.
Symptoms
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Restlessness
Euphoria
Hyperactivity
Inability to sleep or relax
May become violent or psychotic
(heavy use)
Dilated pupils
© 2007 The McGraw-Hill Companies, all rights reserved.
Problems with use/abuse
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Withdrawals are severe
Causes violent behavior
May cause acute psychosis like paranoid
schizophrenia
Manufacture of chemicals release toxic
fumes, not all is manufactured correctly –
may kill the user upon use.
If user has not slept in a while, will
hallucinate
© 2007 The McGraw-Hill Companies, all rights reserved.
Withdrawal Symptoms
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Severe depression
May sleep for days after a binge
Chronic fatigue
Severe hunger
© 2007 The McGraw-Hill Companies, all rights reserved.
Forensic Tests
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Marquis color test – reagent turns
orange-brown in the presence of
amphetamines and
methamphetamines
Microcrystalline test
© 2007 The McGraw-Hill Companies, all rights reserved.
II. Major Classes of Abused Drugs
Club Drugs:
 MDMA, the “love drug” or “Ecstasy” is either
prepared by clandestine labs, or obtained legally
from other countries
 GHB, gamma hydroxybutyrate, is synthesized in
clandestine labs or diverted from legal production
 GHB and related compound GBL, are used for their
hypnotic or depressant
effects
© 2007 The McGraw-Hill Companies, all rights reserved.
II. Major Classes of Abused Drugs
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Ketamine, is an anesthetic and animal
tranquilizer that can cause anterograde
amnesia, the loss of memory while under its
influence
Rohypnol, GHB, and ketamine have been
implicated in cases of drug-facilitated sexual
assaults, thus also known
as “date-rape” drugs
© 2007 The McGraw-Hill Companies, all rights reserved.
II. Major Classes of Abused Drugs
Athletic Performance Enhancers:
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Athletes trying to gain a competitive edge may
abuse stimulants and painkillers
The first drug controlled because of their abuse by
athletes were anabolic steroids
Anabolic steroids promote cell growth
resulting in growth of muscle tissue and
sometimes bone size and strength
© 2007 The McGraw-Hill Companies, all rights reserved.
Steroids
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Anabolic steroids – promote muscle
growth
Testosterone
Androgens
© 2007 The McGraw-Hill Companies, all rights reserved.
How the drugs works
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Injected or ingested
Stimulates growth of muscle and
development of masculine traits
(deep voice, aggressiveness, facial
hair)
© 2007 The McGraw-Hill Companies, all rights reserved.
Symptoms

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
Muscle development
Moods swings – aggressive in nature
Depression
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Problems with use/abuse

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

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
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Gives little to marginal increased strength
or enhanced performance
Harmful medical side effects
Liver cancer and liver malfunction
Infertility in females
Decreased testicular size, sex drive and
sperm count in males
Premature halting of bone growth in
teenagers
Frequent mood swings, tendency towards
aggressiveness
Depression
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Withdrawal symptoms


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Psychologically addictive – need it to
get ahead, etc
Triggers depression
Muscle mass reverts to adipose
tissue
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Forensic Tests


GC/Mass Spec
Blood/Urine tests
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III. Controlled Substance Laws


A controlled substance is a drug named in either
federal or state statutes that is illegal to possess
except when prescribed by a physician
The federal government has created 5 controlled
substance schedules, based on their potential for
abuse and medical value
•
•
•
•
•
No medical use (heroin, LSD, marijuana)
Some medical use (Cocaine, morphine)
Anabolic steroids are placed in this schedule
Has most of the tranquilizers & many diet drugs
Exempt preparations: e.g. cough syrup with codeine
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IV. Analysis of Controlled Substances
in the Forensic Laboratory
Screening tests:



Drug test kits are packets used by police officers in
the field to screen for drugs
The tests are simple to perform and based on color
changes
A small amount of drug is
added to the pouch, a
sealed ampoule(s) is then
broken to release a
chemical reagent, mixed,
and the color change noted
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IV. Analysis of Controlled Substances
in the Forensic Laboratory



The screening tests are important for
establishing probable cause when making a
drug possession arrest
However, the screening tests are not a
substitute for laboratory analysis
Commonly used screening tests are:
•
•
•
•
The
The
The
The
Scott test for cocaine
Duquenois-Levine test for marijuana
Marquis test for opiates
Van Erk test for many hallucinogenic drugs
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IV. Analysis of Controlled Substances
in the Forensic Laboratory
Isolation and Separation:



Steps may include an initial microscopic
examination to determine the number of
materials that may be present
A purification step to separate the controlled
substance from other materials, such as
diluents (materials added to a drug to give
bulk/volume)
A liquid-liquid extraction or various types of
chromatography are commonly used separation
techniques
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IV. Analysis of Controlled Substances
in the Forensic Laboratory
Microcrystal Tests:




A confirmatory test that can be used directly with
street drug samples is the microcrystal test
The test is performed by taking a small amount of
drug, placing it on a microscope slide and adding a
drop of reagent
The shape (morphology) of the
crystal formed is characteristic
for that particular drug and
reagent
The tests are rapid and specific
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IV. Analysis of Controlled Substances
in the Forensic Laboratory
Chromatography (Separations):



Chromatography is a process that separates a mixture of
different compounds
Separation is achieved by the differences in the
partitioning of compounds between two phases: a
moving phase and a
stationary phase
Chromatography
provides tentative
identification, based
on retention time (GC)
or distance traveled
(TLC)
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IV. Analysis of Controlled Substances
in the Forensic Laboratory
Spectroscopy/Spectrometry:


Spectroscopy refers to the interaction of electromagnetic radiation with a chemical to give a pattern
(spectrum) characteristic of that material’s
interaction with the radiation
Mass spectroscopy
(MS) or infrared
spectroscopy (IR)
are excellent ways
to identify drugs
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IV. Analysis of Controlled Substances
in the Forensic Laboratory
Spectroscopy/Spectrometry:


Spectroscopic methods work best with samples that
are relatively pure, thus often combined with gas
chromatography (GC-MS; GC-IR)
The combination of liquid
chromatography and
mass spectrometry
(LC-MS) provides a
retention time along
with a spectrum for
unambiguous
identification
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IV. Analysis of Controlled Substances
in the Forensic Laboratory
Qualitative versus Quantitative Analysis:
 Qualitative analysis means determining whether
something is there or not there
 With most drug laws, a qualitative identification
is all that is necessary (“aggregate weight based
law”)
 Quantitative analysis indicates how much of that
sample is made up of a controlled substance
(percentage of the total for each controlled
substance present in a sample)
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V. Forensic Toxicology
Antemortem and Postmortem





Forensic toxicologists receive blood, urine or body tissue
for analysis
Toxicologists must be able to analyze small amounts of
drug and isolate them from a complex biological matrix
In contrast to the work typically done by drug chemists,
a toxicologists needs quantitative information in order to
determine if the amount is consistent with a therapeutic
dose or an abuse dosage
Toxicologists must aid others in understanding the effects
of the substance on the human body
Samples from living individuals (antemortem) and
deceased (postmortem) are received for analysis
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V. Forensic Toxicology
Antemortem and Postmortem
Antemortem Sample Analysis:
 A number of laws and rules have to do
with the workplace use of drugs
 Urine specimens from random drug testing
are sent to the forensic lab for toxicology
analysis
 Forensic Toxicology labs also test for the
presence of certain drugs in victims of
sexual assault, who may have been
drugged as an adjunct to the assault
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V. Forensic Toxicology
Antemortem and Postmortem
Postmortem Sample Analysis:




Medical examiners are responsible for determining
the cause and manner of sudden, suspicious, or
unattended death
Postmortem toxicology is done to assist the medical
examiner with this determination
Toxicologist’s work is complicated by the limited
amount of drug in the body and by the natural
process of metabolism
The toxicologist looks for both the drug itself and
the metabolites
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V. Forensic Toxicology
Antemortem and Postmortem
Classes of Poisons:


The presence of poisons in the body may
be critical to law enforcement or public
health investigations
Three basic groups of poisons:
• Inorganic (arsenic, cadmium, cyanide)
• Organic (strychnine, curare, digitalis)
• Biological (venoms, botulism, tetradotoxin)
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