Introduction to Forensic
Science and Criminalistics
Prepared byPeter Bilous
Eastern Washington University
Chapter 12
© 2007 The McGraw-Hill Companies, all rights reserved.
Drugs and Drug Analysis and Forensic Toxicology
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 drug2b. 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
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
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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
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.
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
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
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
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: 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.
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
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
6. Athletic Performance Enhancers: 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
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 Scott test for cocaine• The Duquenois-Levine test for marijuana• The Marquis test for opiates• The 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 electro-
magnetic 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 ToxicologyAntemortem 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 ToxicologyAntemortem 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 ToxicologyAntemortem 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 ToxicologyAntemortem 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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VI. Alcohol and Drugs and Driving
Driving While Impaired by Alcohol: 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
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: 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