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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.