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Forensic Science: Fundamentals & Investigations, Chapter 9 1
Introduction Introduction
Forensic toxicology helps determine cause-and-effect relationshipsbetween
o Exposure to a drug or other substance
and o Toxic or lethal effects from that exposure
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Forensic Science: Fundamentals & Investigations, Chapter 9 2
ExposureExposure
People can be exposed to toxic substances:
o intentionallyintentionally—by treating illness or relieving pain
o accidentallyaccidentally—by harmful combinations or overdoses
o deliberatelydeliberately—by harming or killing others, or
by suicide
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Poison—>Murder, Accidental Overdoses, and Drug Offences
o Poisoning causes less than ½ of 1% of all homicides
o Accidental drug overdoses are more Accidental drug overdoses are more commoncommon
o Drug offenders
• More than 50% of the federal prison population
• About 20% of the population in state prisons
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Controlled Substances
1. Hallucinogens
2. Narcotics
3. Stimulants
4. Anabolic steroids
5. Depressants
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Forensic Science: Fundamentals & Investigations, Chapter 9 5
Controlled Substances —Hallucinogens
o Often derived from plantso Affects the user’s perceptions, thinking, self-awareness,
and emotionso Blood 1-3 days, Urine 3-7 +, hair forever
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Controlled Substances-Narcotics
Urine Test
2-3 Days
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Controlled Substances- Stimulants
o Increases feelings of energy and alertness, Suppresses appetite…Afterwards, depression often results
o Overdose affects include high blood pressure, agitation, confusion, seizures
o Stimulants tend to be highly addictiveo Blood: 5-6 hours or 2-3 days, Urine: 1-7+ days (based on use)
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Controlled Substances- Anabolic Steroids
o A chemical structure similar to testosteroneo Promote cell and tissue growth increasing bone
mass and body muscle. o Popular with weightlifters, bodybuilders, and
other athletes
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Controlled Substances —Depressants
o Affects the central nervous system by increasing a neurotransmitter… causes drowsiness and slowed brain activity
o Relieves anxiety and produces sleepo Side effects include slurred speech and loss of
coordinationo Mixing depressants with alcohol and other drugs
increases potency and health risks
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Forensic Science: Fundamentals & Investigations, Chapter 9 10
Controlled Substances—Alcohols
o In what way are alcohols toxic? o How is grain alcohol produced? o What are the classic symptoms of a
hangover? o What is the effect of alcohol on the central
nervous system? o What can chronic alcohol abuse cause?
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Forensic Science: Fundamentals & Investigations, Chapter 9 11
Controlled Substances—Bacterial Toxins
o Tetanus (also called Lockjaw)• Produced by the Clostridium tetani bacteria • Causes violent muscle spasms
o Botulism • Produced by Clostridium botulinum—botulism • Paralyzes muscles• Causes irreversible damage to nerve endings• Extremely deadly in very small amounts• Most poisonous biological substance
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Forensic Science: Fundamentals & Investigations, Chapter 9 12
Controlled Substances—Pesticides and Heavy Metals
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Forensic Science: Fundamentals & Investigations, Chapter 9 13
Controlled Substances—Pesticides and Heavy Metals
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Forensic Science: Fundamentals & Investigations, Chapter 9 14
Controlled Substances—Bioterrorism Agents
Ricin o A poisonous protein in the castor bean o Lethal in extremely small amountso Enters the body in various ways:
• inhaled as a mist or a powder • ingested as food or drink• injected into the body
o Causes death within a few hours
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Forensic Science: Fundamentals & Investigations, Chapter 9 15
Controlled Substances—Bioterrorism Agents
Anthrax o Bacillus anthracis, which forms endosporeso Spreads to humans from infected animals o 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