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FORENSICS
DRUG EVIDENCE
Drugs
• 1. A drug can be defined as a
natural or synthetic
substance that is used to
produce physiological or
psychological effects in
humans or other higher
order animals.
• 2.
–a. Drug dependence
exists in numerous
patterns and in all
degrees of intensity
depending on several
factors.
•There are two types
of dependence –
psychological
dependence and
physical
dependence.
• b. Psychological
dependence – drug abuse is
caused by an underlying
psychological need and the
desire to fulfill them.
• Ex. To escape reality, relief
from personal problems,
stress.
• Drugs with high potential for
BOTH psychological and
physical dependency.
• Narcotics – Morphine,
Heroin, Methadone.
• Depressants – Barbiturates,
Alcohol, Quaalude, Valium
• Stimulants – Amphetamines,
nicotine
• Hallucinogens –
Phencyclidine (PCP)
• The social impact of drug
dependence is directly
related to the extent to
which the user has become
preoccupied with the drug.
• The more frequently the
drug satisfies the person’s
need, the greater the
likelihood that he or she will
become preoccupied with its
use, with a consequence of
neglect of individual and
social responsibilities.
• 3. NARCOTIC DRUGS
–a. Narcotic is derived from
the Greek word
“narkotikos” which means
a state of sluggishness or
lethargy.
• Pharmacologist classify
narcotics drugs as
analgesics. Analgesics
relieve pain by exerting a
depressing action on the
central nervous system.
• The regular use of narcotic
drugs will lead to physical
dependence.
• b. The source of most
analgesic narcotics is
opium. It is a gummy, milky
juice from the unripe pod of
the poppy plant.
• Poppy plants (Papaver
somniferium) is grown
primarily in Asia.
• Opium has a morphine
content from 4 – 21%.
• Most addicts prefer a
derivative of morphine heroin.
• Heroin is made by reacting
morphine with acetic
anhydride or acetyl chloride.
• c. Codeine is also present
in opium but is usually
prepared synthetically from
morphine. Commonly used
as a cough suppressant in
cough syrup.
• It is 1/6 as strong as
morphine.
• d. There are other narcotics
not derived from opium.
These are referred to as
opiates. The most common
is the drug Oxycontin whose
main ingredient is
oxycodone.
• Seven million Oxycontin
prescriptions are written
each year for the treatment
of pain.
• It is estimated that here are
250,000 people currently
abusing the drug.
• Another synthetic opiate is
methadone. It is often used
as a treatment / substitute
for heroin addiction because
it neutralizes its effect.
• 4. Hallucinogens – drugs
that can cause marked
alterations in normal
thought processes,
perceptions, and moods.
• The most common drug in
this category is marijuana.
• Derived from the plant
Cannabis satira. The plant
secretes a sticky resin
known as hashish.
• Marijuana's medical use has
been documented as far
back as 2737 B.C. in China.
• It was also used as the main
source of rope making fiber.
• In 1964 scientist isolated the
chemical substance
responsible for its
hallucinogenic properties.
• It is tetrahydrocannabinol
(THC)
• Medical marijuana has uses
for the treatment of
glaucoma (it reduces the
internal pressure of the eye)
and the lessening of nausea
caused by anticancer drugs.
• 5. Other Hallucinogens
– a. LSD is synthesized from
lysergic acid, a substance
derived from ergot, a type
of fungus that attacks
grasses and grains.
• 25 micrograms is sufficient
to produce visual
hallucinations for 12 hours
along with intense feelings
of anxiety and tension.
• b. PCP (phencyclidine)
• Is easily synthesized by
anyone with a “recipe”.
• PCP is often mixed with LSD
or amphetamines and is
sold as a powder (angel
dust), capsule, or tablet.
• Effects produced are
unresponsiveness,
confusion, agitation,
depression, and paranoia.
• 6. Depressants
–a. The most commonly
used depressant is
alcohol. In the U.S. the
alcohol industry has an
annual income of 40 billion
dollars.
• Alcohol acts to suppress the
brain’s control of thought
processes and muscle
coordination.
• It also inhibits judgment,
memory, and concentration.
• b. Barbiturates are derived
from barbituric acid by a
German chemist Adolf Von
Bayer about 100 years ago.
• c. Tranquilizers – used to
reduce anxiety and tension.
• Most common is Valium.
These have a high potential
for both physical and
psychological dependency.
•
• d. Glue-sniffing
–Began in the 1960’s by
inhaling volatile solvents
like model glue.
–Recently added to this
category are aerosol gas
propellants such as freon.
• Toluene, naphtha, gasoline,
and ethyl keytone are also
used.
• Users suffer from liver,
heart, and brain damage
from the chemicals.
• 7. Stimulants
– a. Amphetamines are a
group of synthetic drugs
that stimulate the central
nervous system.
• Effects are increased
alertness followed by an
increase in fatigue, loss of
appetite, and depression.
• Chronic users exhibit violent
destructive behavior and
acute psychosis similar to
paranoid schizophrenia.
• The repeated use of
amphetamines leads to a
strong psychological
dependency which
encourages their continued
administration.
• b. Cocaine is a drug
extracted from the leaves of
Erythroxylon coca. Once
used as pain medication and
anesthetic.
• c. Club drugs are synthetic
drugs that are used at
nightclubs, bars, and raves.
• Many are central nervous
system depressants that are
often connected with drugfacilitated sexual assault,
rape, and robbery.
• Effects are muscle
relaxation, sedation, loss of
consciousness, and the
inability to remember what
happened during the hours
after ingestion.
• Most are odorless,
colorless, and tasteless and
will remain undetected when
slipped into a drink.
• Methylenedioxymethamphetamine (ecstasy)
• Chronic use leads to
seizures, stroke, kidney
failure, cardiovascular
system failure, brain
damage, nausea, confusion,
paranoia, and anxiety.
• 8. Anabolic steroids are
synthetic compounds that
are chemically related to the
male sex hormone
testosterone.
• One of the effects of
testosterone is that it
accelerates muscle growth.
This is called an anabolic
effect.
• Often taken by athletes to
increase performance.
• Liver cancer, infertility,
diminished sex drive, halting
of bone growth, mood
swings, and depression are
side effects of its use.
• 9. Drug Control Laws
–The severity of a penalty
associated with the
manufacture, distribution,
possession, and use of a
drug is dependent on the
weight of the drug or its
concentration in a mixture.
• It is the forensic chemists
responsibility to make sure
all the information is correct
in order to properly charge
the suspect.
• Controlled Substance Act
- The federal government
divides drugs into five
categories or
classifications.
These are based on a drug’s
potential for abuse,
potential for physical and
psychological dependence,
and medical value.
They are grouped into
Schedules I, II, III, IV, V.
• The most severe penalties
are associated with
schedule I and II drugs. First
offence can be punished by
20 years and/or fines up to
$1 – 5 million.
• The Controlled Substance
Act also includes provisions
for substances that are
chemically similar to or
copies of drugs. These are
designer drugs and carry
the same penalty as the
drug they are copying.
• The Act also has the
authority to control and
regulate the manufacture
and sale of precursor
chemicals to make it harder
for illegal drug labs to make
the illegal drug.
• 10. DRUG IDENTIFCATION
• a. The forensic chemist will
be given a sample of
unknown origin and
composition. Her job is to
identify this substance.
• Their plan to accomplish
this has two parts.
• The first part includes
screening tests to reduce
the possibilities to a
manageable number.
Usually based on physical
appearance.
• Once the possibilities have
been reduced the second
phase, determining exactly
the identity and
concentration of the drug
begins.
• b. There are many test that
can be conducted to confirm
a drugs identity.
• These include color test,
microcrystalline test,
chromatography,
spectrophotometry, and
mass spectrometry.
• c. Color tests
–Many drugs will turn a
specific color when
brought into contact with
specific chemical reagents.
–Color tests are usually
used in the first phase for
screening purposes.
–There are five primary
color test reagents.
•1. MARQUIS made with
formaldehyde and H2SO4
•Turns purple when in
contact with heroin,
morphine and most
opium derivatives.
–Turns orange when in
contact with
amphetamines and
methamphetamines.
–2. DILLIE – KOPPANYI
•Turns violet/blue when in
contact with barbiturates.
• 3. DUQUENOIS – LEVINE
–Turns purple in contact
with marijuana.
4. VAN URK – turns
purple/blue with contact
with LSD.
• 5. SCOTT TEST – turns blue
in contact with cocaine.
• d. Microcrystalline Test
–Is more specific than
color tests.
–A chemical reagent is
added to a small quantity
of the drug placed on a
microscope slide.
• Crystals will begin to form
after the chemical reaction
takes place between the
drug and the reagent.
• The shape and size of
these crystals are highly
characteristic of each
drug.
• Chromatography – helpful
because it separates drugs
from other substance that
may be present in a sample.
• Spectrophotometry –
Different drugs absorb
different wavelengths of
light in the UV and IR
region.
• The pattern of absorption of
each drug is characteristic
of that drug.
• Identification of Marijuana
–Different because it is
plant material with
identifiable characteristics.
–The upper side of the leaf
has short, distinctively
shaped hairs called
cystolithic hairs.
• The opposite side of the leaf
has longer, distinct hairs.
• Forensic Toxicology
• 1. Toxicologist look for the
presence or absence of drugs
and poisons in the bodies
fluids and organs.
• 2. Toxicologist work for crime
labs and medical examiners
offices. They also work for
hospitals and other health
facilities.
• A. TOXICOLOGY OF
ALCOHOL
• 1. Alcohol is the most widely
abused drug in Western
countries. In the U.S. 12,500
automobile deaths (40%) are
alcohol related, with 2 million
people per year hospitalized
from injuries.
B. What happens to alcohol in
the body?
1. There are many factors that
must be taken into account
when considering the effects of
alcohol on a person.
• 2. Alcohol is a depressant that
effects the central nervous
system, especially the brain.
• 3. The extent of the depression
is directly proportional to the
concentration of alcohol within
the nerve cells.
• The first part of the brain to be
effected is the forebrain
(movement, behavior,
emotion, problem solving).
• Then the central (orientation,
visual processing) and rear
portions (memory,
perception) are effected.
•Last is the medulla
region. This is the area
responsible for controlling
breathing and heart
function.
• 4. How can you determine how
much alcohol is effecting an
individual?
• It is the blood that distributes
the alcohol around the body
• 5. Blood-alcohol concentration
is directly proportional to the
alcohol concentration of
alcohol in the brain.
• 6. Alcohol is absorbed from the
stomach and intestine minutes
after being ingested. When all
the alcohol has been absorbed
the maximum level is reached.
Then the post absorption
period begins and the alcohol
concentration level drops to
zero again.
• 7. Several factors influence the
rate at which alcohol is
absorbed including:
–Total time taken to consume
alcohol.
–Amount of alcohol
consumed.
–Quantity and type of food in
the stomach.
• 8. During the absorption phase
blood distributes the alcohol
throughout the body. When the
absorption phase is complete
the alcohol is distributed
evenly throughout the watery
parts of the body (2/3 of it).
• 9. The body begins to rid itself
of alcohol shortly after it is
absorbed. Elimination is
accomplished by 2
mechanisms – oxidation and
excretion.
• 10. Oxidation is the
combination of oxygen with
other substances to produce
new products. 95 to 98% of
the alcohol is oxidized into
CO2 and H2O. Oxidation
happens in the liver.
• 12. The rest of the alcohol is
excreted in the breath, urine,
and sweat. The amount of
alcohol exhaled is directly
proportional to the
concentration of alcohol in the
blood. This fact has led to the
development of test that
confirm alcohol content.
• C. Alcohol in The Circulatory
System.
1. Remember humans have a
closed circulatory system
consisting of heart, arteries,
capillaries, and veins. Arteries
carry blood away from the
heart.
• Veins carry blood
` toward the
heart. Capillaries are very
small vessels connecting
arteries and veins. Diffusion
happens in the capillaries.
• 2. After alcohol is consumed it
moves down the esophagus
into the stomach. About 20%
of the alcohol is absorbed
through the stomach wall into
the blood system.
• The remaining alcohol passes
into the blood through the
walls of the small intestine.
• Once in the blood the alcohol
is carried through the liver to
the heart.
• Blood enters the upper right
atrium then is forced into the
right ventricle.
• Then to the lungs where CO2
can be exchanged for O2. The
pulmonary artery branches
into capillaries that are very
close to the alveoli (small sacs
in the lungs through whose
walls air is exchanged
between breath and blood).
• There are about 250 million
alveoli in the lungs. They are
connected to the bronchial
tubes that are connected to
the trachea (windpipe).
• If there is alcohol in the blood
it will be exchanged with the
CO2 for O2 and exhaled.
• The freshly oxygenated blood
is taken back to the left atrium
then to the left ventricle then
into arteries which distribute
blood throughout the body.
• These arteries pass into
smaller ones then into
capillaries. It is here that the
alcohol in the blood diffuses
into the tissues.
• D. Breath –Test Instruments
• 1. The breathalyzer is used to
determine the amount of
alcohol in the breath.
• The air that is trapped in the
machine is combined with
potassium dichromate, sulfuric
acid and water.
• The alcohol dissolves into the
potassium dichromate and is
oxidized into acetic acid. In
this oxidation process the
potassium dichromate is
destroyed. The amount that is
destroyed is proportional to the
amount of alcohol present.
• 2. Field Sobriety Tests are
normally performed to
ascertain the degree of the
suspect’s physical impairment
and whether or not other test
are needed.
a. Horizontal Gaze Nystagmus
– the involuntary jerking of
the eye as it moves to the
side. A person experiencing
nystagmus is unaware of the
jerking and unable to stop or
control it.
• They are asked to follow an
object with their eyes as far as
they can. With a blood-alcohol
level of 0.10 percent the
jerking motion will begin
around 45 degrees. Higher
blood-alcohol content and the
jerking begins at smaller
angles.
• b. The walk-and-turn requires
walking heel-to-toe for nine
steps then turning and
repeating the process.
• C. The one-leg stand requires
the suspect to maintain
balance while standing with
heels together then standing
with one foot off the ground
balancing on the other and
counting to 30.
• E. The analysis of blood for
•
alcohol
• 1. Gas chromatography can be
used on blood samples to
determine the alcohol level in
blood.
• F. Collection and Preservation
of Blood
1. Once blood is removed from
an individual it should be kept
in a sealed air-tight container
after an anticoagulant and
preservative are added.
• The anticoagulant keeps the
blood from clotting and the
preservative stops the growth
of microorganisms.
• G. Alcohol and the Law
• 1. In 1992 the U.S.
Department of Transportation
recommended that states
adopt a 0.08 percent bloodalcohol concentration as the
legal measure of drunk driving.
• If states chose not to adopt
this level they will lose Federal
funds for highway
construction.
• For commercial truck drivers
the limit is 0.04.
• 2. Can a person refuse to take
a test for alcohol levels?
• Yes. In 1973 states adopted an
“implied consent” law. This law
says the operation of a motor
vehicle on a public road
automatically carries with it the
stipulation that the driver will
have the choice of either
submitting to a test or be
subject to losing their license.
• 3. The 5th Amendment refers to
self-incrimination. In
Schmerber v. California the
Supreme Court ruled that the
5th Amendment applies only to
testimonial evidence and not
to physical evidence such as
fingerprints, DNA, and blood
samples.
• H. The Role of the Toxicologist
• 1. How does the toxicologist
go about determining the toxin
or poison in a sample?
• First they look for clues in
personal effects like pill
bottles, containers etc. If these
are not available they begin a
screening process.
• They must use samples that
have been extracted from
bodily fluids and organs for
testing. The amounts of the
drugs may be very small
(nanograms or micrograms).
• Another problem toxicologist
face is that most drugs change
to something else when they
enter the body because they
are metabolized.
• I. Techniques Used in
Toxicology
• 1. The process of extracting a
drug from a biological
specimen is complex.
• 2. Most drugs fall into
categories of acids or bases.
• An acid is a compound
capable of donating a
hydrogen ion to another
compound.
• A base is a compound capable
of accepting a hydrogen ion.
• Acids and bases are
measured on a pH scale.
• The pH scales goes from 0 to
14.
• A pH of 7 is neutral.
• Below 7 is acidic with 0 being
the most acidic.
• Above 7 is basic with 14 being
the most basic.
• By controlling the pH of a
water solution into which a
sample is dissolved the
toxicologist can tell if the
extracted drug falls into the
acid or base categories.
• 3. Then they begin the process
of screening and confirmation.
• The three most widely used
screening tests are
–Thin-layer chromatography
–Gas chromatography
–Immunoassay
• Immunoassay is a process
based on specific drug
antibody reactions. Its primary
advantage is its ability to
detect small concentrations of
drugs in body fluids and
organs.
• Gas chromatography/mass
spectrometry is the most
commonly used method of
confirming a drug.
• 4. Forensic toxicologist also
must test for heavy metals.
These include arsenic,
bismuth, antimony, mercury,
and thallium.
• This is done by dissolving the
sample in hydrochloric acid
and inserting a copper strip.
• If a silvery or dark coating
appears on the strip it
indicates the presence of a
heavy metal.
• This is called the Reinsch Test.
• Another poison frequently
encountered is carbon
monoxide. When it enters the
body it is absorbed by the red
blood cells where it combines
with hemoglobin to form
carboxyhemoglobin.
• An average red blood cell
contains about 280 million
molecules of hemoglobin. The
hemoglobin is what carries
oxygen around the body to the
tissues.
• If a high percentage of
hemoglobin is carrying carbon
monoxide instead of oxygen
death by asphyxiation will
occur.
• The amount of carbon
monoxide in blood is
expressed as percent
saturation.
• This represents the extent to
which the available hemoglobin
has been converted to
carboxyhemoglobin.
• A level of 50 – 60 percent is
usually fatal.
• A level of 35 – 40 percent may be
fatal if the blood-alcohol level is
elevated.
• Suicide by automobile is
common.
• Carbon monoxide levels are
also measured in victims of
fires. The presence of high
levels of carbon monoxide in
the blood indicated they were
alive when the fire began.
Absence means?
• Common poisons and their
symptoms.
–Arsenic, mercury, copper,
metals; severe unexplained
diarrhea, vomiting
–Atropine; dilated pupil of the
eye
–Carbon monoxide; skin is
bright cherry red
–Cyanide; quick death, red
skin, odor of peaches.
–Food poisoning; vomiting,
abdominal pain
–Nicotine; convulsions
–Strychnine; convulsions,
dark face and neck
• There are about 700 deaths
by poisoning reported each
year.
• Children under 6 account for
the majority of poisons
reported but adults account
for the majority of deaths.
• Most frequently reported
poisonings
–household cleaning
supplies
–aspirin
–cosmetics
–cough and cold medicine
–plant scrapes and insect
bites
- pesticides
- gasoline and kerosene
- sedatives, antipsychotics
- food poisonings
- alcohol
• Most frequent deaths by
poisoning
– Antidepressants
– Street drugs
– Cardiovascular drugs
– Alcohol
– Gases and fumes
- Industrial chemicals
- Pesticides
- Household cleaning
supplies