1. Chapter 9 Drug Identification and Toxicology By the end of this chapter you will be able to:
Identify the five types of controlled substances
Relate signs and symptoms of overdose with a specific class of drugs or toxins
Describe the role of various types of toxins in causing death
Discuss agents that may be used in bioterrorism
Define and describe the goals and practice of toxicology
All Rights Reserved South-Western / Cengage Learning © 2012, 2009
Forensic Science: Fundamentals & Investigations, Chapter 9

2. Introduction
Forensic toxicology helps determine cause-and-effect relationships
between
Exposure to a drug or other substance
and
Toxic or lethal effects from that exposure
Forensic Science: Fundamentals & Investigations, Chapter 9

3. Introduction People can be exposed to toxic substances:
intentionally— by treating illness or relieving pain
accidentally— by harmful combinations or overdoses
deliberately— by harming or killing others, or by suicide
Forensic Science: Fundamentals & Investigations, Chapter 9

4. Poison—Murder, Accidental Overdoses, and Drug Offences
Poisoning causes less than ½ of 1% of all homicides
Accidental drug overdoses are more common
Drug offenders
More than 50% of the federal prison population
About 20% of the population in state prisons
Forensic Science: Fundamentals & Investigations, Chapter 9

5. Controlled Substances
Hallucinogens
Narcotics
Stimulants
Anabolic steroids
Depressants
Forensic Science: Fundamentals & Investigations, Chapter 9

6. Controlled Substances —Hallucinogens
Often derived from plants
The effect and intensity of response to these drugs varies from person to person.
Affects the user’s perceptions, thinking, self-awareness, and emotions
Forensic Science: Fundamentals & Investigations, Chapter 9

7. Controlled Substances —Hallucinogens
Affects of an overdose often include
Increased heart rate
Increased blood pressure
Panic attacks, anxiety, or psychosis
Forensic Science: Fundamentals & Investigations, Chapter 9

8. Controlled Substances —Hallucinogens
Forensic Science: Fundamentals & Investigations, Chapter 9

9. Controlled Substances —Narcotics
Forensic Science: Fundamentals & Investigations, Chapter 9

10. Controlled Substances —Stimulants
Increases feelings of energy and alertness
Suppresses appetite
Afterwards, depression often results
Overdose affects include high blood pressure, agitation, confusion, seizures
Stimulants tend to be highly addictive
Forensic Science: Fundamentals & Investigations, Chapter 9

11. Controlled Substances —Stimulants
Forensic Science: Fundamentals & Investigations, Chapter 9

12. Controlled Substances —Anabolic Steroids
A chemical structure similar to testosterone
Promote cell and tissue growth increasing bone mass and body muscle.
Popular with weightlifters, bodybuilders, and other athletes
What are some of the negative side effects?
Forensic Science: Fundamentals & Investigations, Chapter 9

13. Controlled Substances —Depressants
Affects the central nervous system by increasing GABA activity, a neurotransmitter
Increased GABA causes drowsiness and slowed brain activity
Relieves anxiety and produces sleep
Side effects include slurred speech and loss of coordination
Mixing depressants with alcohol and other drugs increases potency and health risks
Forensic Science: Fundamentals & Investigations, Chapter 9

14. Role of Forensic Toxicology
Toxicology is the study of drugs and poisons, and their interactions with or effects on the body
A drug is a natural or synthetic substance that is used to produce physiological or psychological effects
Forensic Toxicology is the application of toxicology to the law, including
Workplace or Forensic Drug Testing
Postmortem Toxicology
Human Performance Testing

15. Toxicology of Alcohol
Approximately 40% of traffic deaths in the U.S. are alcohol-related (Flinn, 2012)
Toxicologists have had to develop specific procedures for measuring the degree of alcohol intoxication
Methods for diagnosis must be defendable within the framework of the legal system

16. Toxicology of Alcohol (continued)
Metabolism involves the body’s ability to break down chemicals. There are three steps:
Absorption
Alcohol appears in the blood minutes after consumption
Alcohol slowly enters the body’s bloodstream and is carried to all parts of the body

17. Toxicology of Alcohol (continued)
Metabolism (continued)
Distribution
When absorption is complete, alcohol becomes distributed uniformly throughout
Factors affecting absorption and distribution are
Speed of consumption
Percentage of alcohol content
Quantity of alcohol consumed
Quantity and type of food present in the stomach

18. Toxicology of Alcohol (continued)
Metabolism (continued)
Elimination
The body begins to eliminate alcohol as it is circulated through the bloodstream
There are two mechanisms for elimination
Oxidation, which occurs in the liver
Excretion through breath, urine, and perspiration

19. Toxicology of Alcohol (continued)
To determine the blood alcohol level, analyzing brain tissue would be best. However, brain tissue is not available from a living individual, so blood alcohol concentrations are used. Blood and brain concentrations are directly proportional
Measuring the quantity of alcohol consumed can be done by analyzing either blood or breath

20. Toxicology of Alcohol (continued)
Testing for Intoxication
Breath testing
The most widespread method
The Breathalyzer measures alcohol content in alveolar breath (deep within the lungs)
It requires no less than 1.1 to 1.5 liters of breath to ensure that “deep-lung” breath is measured
For accuracy, avoid “mouth alcohol,” such as that from belching, regurgitation, or recent mouthwash

21. Toxicology of Alcohol (continued)
Testing for Intoxication (continued)
Field Sobriety
A preliminary test performed to ascertain the degree of a suspect’s physical impairment and whether further tests are justified

22. Toxicology of Alcohol (continued)
Testing for Intoxication (continued)
Field Sobriety (continued)
Psychophysical tests
Horizontal-gaze nystagmus
Walk and turn
One-leg stand

23. Toxicology of Alcohol (continued)
Testing for Intoxication (continued)
Field Sobriety (continued)
Preliminary Breath Test
A handheld breath tester that uses a fuel cell to measure alcohol content
Should establish probable cause for requiring more thorough breath or blood tests

24. Toxicology of Alcohol (continued)
Blood Analysis
Calculated with a high degree of accuracy by use of gas chromatography which separates alcohol from any other chemicals
Collection and preservation of blood
Before the penetration of the needle, the area must be cleaned with non-alcoholic disinfectant
Refrigerate the blood until it is delivered to the lab
Effects on the collected blood
Storage temperature
Presence of a preservative, such as sodium fluoride
Amount of time in storage
Postmortem blood should be collected from a variety of body sites if it is available at all

25. Toxicology of Alcohol (continued)
Blood Alcohol Laws (Morgan, 2012)
The Department of Transportation recommended that states adopt .08% blood alcohol concentration as the legal measure for drunk driving
This percentage has been adopted by all 50 states
.08% only applies to noncommercial drivers; for commercial drivers, it is .04%
An implied consent law is used to prevent a person from refusing to take a blood or breath test based on self-incrimination rights

26. Controlled Substances —Alcohols
In what way are alcohols toxic?
How is grain alcohol produced?
What are the classic symptoms of a hangover?
What is the effect of alcohol on the central nervous system?
What can chronic alcohol abuse cause?
Forensic Science: Fundamentals & Investigations, Chapter 9

27. Controlled Substances —Bacterial Toxins
Tetanus (also called Lockjaw)
Produced by the Clostridium tetani bacteria
Causes violent muscle spasms
Botulism
Produced by Clostridium botulinum—botulism
Paralyzes muscles
Causes irreversible damage to nerve endings
Extremely deadly in very small amounts
Most poisonous biological substance
Forensic Science: Fundamentals & Investigations, Chapter 9

28. Controlled Substances —Pesticides and Heavy Metals
Forensic Science: Fundamentals & Investigations, Chapter 9

29. Controlled Substances —Pesticides and Heavy Metals
Forensic Science: Fundamentals & Investigations, Chapter 9

30. Controlled Substances —Bioterrorism Agents
Ricin
A poisonous protein in the castor bean
Lethal in extremely small amounts
Enters the body in various ways:
inhaled as a mist or a powder
ingested as food or drink
injected into the body
Causes death within a few hours
Forensic Science: Fundamentals & Investigations, Chapter 9

31. Controlled Substances—Bioterrorism Agents
Anthrax
Bacillus anthracis, which forms endospores
Spreads to humans from infected animals
Enters the human body through:
Inhalation; causing breathing problems that usually result in death
Ingestion; becoming fatal in 25% to 60% of cases
Absorption via the skin; leading to death in about 20% of untreated cases
Forensic Science: Fundamentals & Investigations, Chapter 9

32. Summary
Forensic toxicology seeks to identify poisons or drugs in criminals and victims.
Toxicology is important in studying cases of drug overdose and sporting violations.
Forensic Science: Fundamentals & Investigations, Chapter 9

33. Summary
Controlled substances fall into five main groups:
Hallucinogens
Narcotic
Stimulants
Steroids
Depressants
Forensic Science: Fundamentals & Investigations, Chapter 9

34. Summary
Poisons can be produced by living organisms.
Pesticides and heavy metals are common poisons.
Bioterrorism agents include ricin and anthrax.
Forensic Science: Fundamentals & Investigations, Chapter 9