Transcript Drugs and Toxicology

Introduction to
Forensic
Science and
Criminalistics
Chapter 12
Prepared by
Peter Bilous
Eastern Washington
University
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
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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
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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
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I. Nature of Drugs and Drug Abuse
Drugs and Society - Controlled Substances:
 Access to drugs is regulated by the Federal
Controlled Substances Act and by State Acts in
all 50 States
 The Drug Enforcement Administration of the US
DOJ administers the Controlled Substances Act
 Society through its laws tries to control the
abuse of drugs
 Forensic science laboratories are involved with
cases where drugs have been abused
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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
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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
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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.
II. Major Classes of Abused Drugs
2. 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
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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
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II. Major Classes of Abused Drugs
3. 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
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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
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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
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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
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II. Major Classes of Abused Drugs
4. 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
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II. Major Classes of Abused Drugs
5. 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
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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
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II. Major Classes of Abused Drugs
6. 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
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III. Controlled Substance Laws
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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
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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:
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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
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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:
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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:
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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:
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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):
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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:
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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:
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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
© 2007 The McGraw-Hill Companies, all rights reserved.
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)
© 2007 The McGraw-Hill Companies, all rights reserved.
V. Forensic Toxicology
Antemortem and Postmortem
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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
© 2007 The McGraw-Hill Companies, all rights reserved.
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
© 2007 The McGraw-Hill Companies, all rights reserved.
V. Forensic Toxicology
Antemortem and Postmortem
Postmortem Sample Analysis:
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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:
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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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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)
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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
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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
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