Forensic Analysis of

Drugs:Drug Categories

• Drug = a natural or synthetic substance that is used to produce physiological or psychological effects

• Why important to forensics?– 75+ % of evidence analyzed in crime labs is drug

related– Huge expansion in analytic capabilities of drug

labs to process these samples

Drug Dependence

• Psychological– Emotional need (can be severe)– Craving

• Physical– Brought on by regular use– Experience withdrawl symptoms when abruptly

stopped (can result in death)

Narcotics

• Def: analgesic/pain killing substance that depresses vital body funtions (BP, pulse, breathing)

• Regular use results in physical dependence• “narcotic” often used incorrectly for any drug

that is socially unacceptable• Derivatives of opium

Narcotics• Morphine

– extracted from opium• Heroin – react morphine with acetyl anhydride– water soluble (IV use), 35% pure (lots of fillers!)

• Codeine– In morphine but usually synthesized in lab– 1/6 the strength of morphine

• Fentanyl– 100x more potent than morphine

Narcotics- not derived from opium but considered opiates

• Methadone– related to heroin and used to treat addiction

• Prescription pain killers– Percocet– often abused due to addictive nature

Hallucinogens

• Def: substance that induces changes in mood, attitude, though or perception

• Can cause psychological dependence

• Many derived from natural substances

Hallucinogens

• Marijuana– From Cannabis plant– Most widely used illicit drug– Active ingredient THC (2-20%)– Medical uses: glaucoma, muscle relaxant, nausea

Hallucinogens

• Peyote– From cactus– Used by American Indians to induce religious

experience

• Magic Mushrooms– Psilocybin = similar to serotonin– High doses can impair cognition

Hallucinogens• LSD = lysergic acid diethylamide– From ergot (fungus that attacks grasses)– Very potent– Flashbacks and psychotic episodes even after

discontinued use• PCP = phencylidine– Synthetic – made from toxic chemicals– Often mixed with other drugs– LT use can lead to suicide, schizophrenia

Hallucinogens

• MDMA/Ecstasy– Synthetic– Originally patented as appetite suppressant– Severe adverse reactions = severe anxiety,

paranoia, etc

Depressants

• Def: substance used to depress the functions of the CNS. Calms irritability and may induce sleep.

• Most can cause physical dependence

Depressants

• Alcohol– Most widely used legal drug– High levels can cause fatal depression of

circulatory and respiratory functions• Barbiturates– Powerful sedatives– Used in medical profession• Quaaludes have similar effect

Depressants

• Tranquilizers– Cause relaxation w/o inducing sleep– Valium and other anti-anxiety meds

• Glue sniffing, huffing, etc

Stimulants

• Def: substance taken to increase alertness. Increase BP, breathing, pulse

• Some cause psychological dependence

Stimulants

• Amphetamines– Meth, phen-phen– Increases alertness but over time causes

depression, anxiety and paranoia

• Cocaine/Crack– Extracted from leaves of coca plant

Anabolic Steroids

• Chemically related to testosterone• Promote muscle growth• Can cause “roid rage”, depression, infertility,

premature stop in bone growth

Drug Schedules

• 5 schedules based on potential for abuse/dependence and medical value

• Schedule I – high potential for abuse/dependence– low medical value

• Schedule V– low potential for abuse/dependence– high medical value

Forensic Analysis of

Drugs:Drug Testing

• Most drugs are composed of a mixture of the active ingredient and fillers/additives.

• This “cutting” is used to stretch the drug so that more money can be made.

• Common additives include sugar, starch, and quinine.

Scheme of Analysis for Determining the Identity of a Drug

– Screening Tests• Used to reduce the number of possibilities to a

manageable number• Quick tests but non-specific in nature. Must be

followed up with confirmation tests.

– Confirmation Tests• Tests used to specifically identify a substance.

Screening Tests

– Color Tests• Drug turns a characteristic color when brought into

contact with certain chemicals.

Screening Tests

– Microcrystalline Tests• Several crystals of the drug are examined under a

microscope and a preliminary identification is made based on the shape and color of the crystals.• Impurities can alter the crystals and throw off results.

Screening Tests

– Chromatography• Used to separate mixtures based on the preferential

affinity (attraction) to the stationary phase or the moving phase.• Used to purify the drug by separating it from the

additives/fillers• Compare Rf values to controls to make an ID

Formula: Rf = distance individual spot moves

distance solvent (moving phase) moves

Screening Tests

• Chromatography

Confirmation Tests

Drugs must be PURE

in order to perform these tests

Confirmation Tests

– Infrared (IR) Spectrophotometry• Electromagnetic radiation is absorbed differently by

chemical bonds in a substance• Provides a unique chemical fingerprint

Confirmation Tests

Mass Spectrophotometry• High energy electrons are shot at a substance breaking

the bonds and creating smaller fragments.• Provides a unique chemical fingerprint• Often used in combination with gas chromatography

(called GS-MS; gas chromatography-mass spectrophotometry)– GC- separates drug from impurities–MS- provides unique chemical ID based on patterns

of fragmentation

Mass Spectrophotometry

Analysis of Marijuana

– Different analysis due to botanical nature– Combination of 2 tests provides conclusive results

1) a specific color test2) microscopic analysis to look for cystolithic hairs (aka “bear claws”) on the leaf