Forensic Chem Exam 3

Blowback

• Fired cartridge exerts pressure to push breechblock back again the spring

• Cartridge is extracted and ejected by the moving breechblock

• Compressed spring propels breechblock forward and new cartridge is removed from magazine and inserted

Recoil

• Barrel of the weapon and the breechblock together

• Breechblock unlocks from the barrel and recoils further backward and compresses a spring

• Compressed spring returns the breechblock to starting position

Gas Piston

• Small hole in the barrel leading to a gas piston

• Small amount of propellant gases pass through the hole and exerts pressure on piston

• Also forces breechblock to rear since piston is connected to it

Revolvers

• Single-action = manually fired by cocking hammer

• Double-action = Fired by long trigger pull that raises the hammer

Pistols

• Semi-automatic = firing of a round will cycle the pistol, eject cartridge casing, and insert new

• Single-shot

• Machine (Automatic)

Firearm Manufacturing Methods

• Inner surface of barrel has markings from manufacturer

  • Barrel hollowed by drilling, which leaves random, non-systematic marks on the inside

  • Drills vary in size = Class characteristic

Stereomicroscopy and Comparison Microscopy of Firearms

• Examine weapons and spent bullet or cartridge cases alongside items recovered from test fires

• Bullet gets impressions in surface from the rifled markings, grooves, twist, striations, and wear characteristics of the weapon

• Evidence and test fired items can be compared at same time

Firearm Individualizing Characteristics

• Metal fragments impressed at random into metal of barrel resulting in bullets gaining striations as it passes through

• Wear and tear from use and improper cleaning can impact unique characteristics

• Microgrooving features imparted by manufacturer form unique individual characteristics

Gunshot Residue Analysis

• GSR and gunpowder residue is projected forward and blown back onto shooter’s firing hand

  • Partially burned and unburn gunpowder particles may be recovered

• Fabrics and surfaces of items receiving the bullet are examines using infrared light and microscope to locate traces

• Distribution of gunpowder particles and other discharge residues around a bullet hole allow assessment of distance from where the gun was fired

• Measures the amount of barium and antimony on portions of suspect’s hands

• Color tests can be done (Pink color = Gunpowder; Blue color = unburned nitrates)

Sonja Farak

• Stole drugs from lab and used drugs while working

• Ethical Issues:

  • Abuse of Drugs in lab → Lack of trust in lab work

  • Evidence tampering → Breach of professional responsibility

  • Lack of accountability

  • Fairness of releasing and returning prisoners

  • Covering up the scandal → Civil justice system failure

• Prevention:

  • Preventing self-assignment of cases

  • No one working alone in labs

  • More funding and better practices

  • Regular surveillance of labs/benches/standards

  • Employee drug tests

New York State Police

• Falsifying evidence

• Ethical Issues:

  • False evidence → False convictions

  • Trivializing crimes and lack of empathy for victims/accused

  • Lack of accountability

• Prevention:

  • Stricter policies (Including auditors, photographs of fingerprints)

  • Less publications including associated officers with cases

  • Regulatory troop movement

Drug Analysis

• Often largest unit/labs

• Most common = Cocaine, Heroin, Fentanyl, Marijuana, and new psychoactive substances

Illicit Drug

legally produced drug that is abused, or a drug that has no legitimate, medicinal purpose that is produced and ingested entirely for its psychoactive effects

Control of Illicit Drugs

• FDA decides based on:

  • Pharmacological effects

  • ability to induce psychological or physical addiction/dependence

  • Whether there is legitimate medical use

• Schedule 1 - 5 (1 being most controlled, 5 being least)

Schedule 1 Drugs

• High potential for abuse

• Physical/psychological addiction

• No currently accepted medical use

• Ex. Heroin, LSD, Marijuana, PCP, Methaqualone

Schedule 2 Drugs

• High potential for abuse

• May lead to severe Physical/psychological addiction

• No currently accepted medical use

• Ex. Morphine, PCP, cocaine, methadone, and methamphetamine

Schedule 3 Drugs

• Has potential for abuse

• Moderate or low Physical/psychological addiction

• No currently accepted medical use

• Ex. Steroids, codeine, hydrocodone, some barbiturates

Schedule 4 Drugs

• Low potential for abuse

• May lead to limited Physical/psychological addiction

• Accepted medical use

• Ex. Darvon, Talwin, Equanil, Valium, Xanax

Schedule 5 Drugs

• Low potential for abuse

• May lead to limited Physical/psychological addiction

• Accepted medical use

• Ex. Over the counter cough meds with codeine

Crack Cocaine

Made by processing the drug into small white/off-white rock crystals that are smoked; Produces faster-acting euphoric effect

Methamphetamine Drug Lab

• Synthesis begins by grinding ephedrine tablets (Blenders used in home labs)

• Starting material extracted using denatured alcohol or another obtainable solvent and solids are filters out using coffee filters

• Red phosphorus collected from match strike pads

• Iodine crystals obtained and acidified to produce hydroiodic acid

• Ephedrine then reacted with red phosphorous and hydroiodic acid

Classification Methods

• Scheduling by addiction potential and medical usage

• By origins

• By psychoactive effects

Classification by Origin

• Naturally occurring

• Plant extracts

• Semi-synthetic

• Synthetic

Naturally Occurring

• Found in nature in plants; part of plant ingested and drug is extracted and used by the person

• Ex. Marijuana leaves; Psylocybin mushrooms eaten; Peyote Cactus buttons eaten

Plant Extracts

• Naturally occurring substances that are extracted from plants and ingested

• Ex. Cocaine extracted from coca plant; Morphine and codeine extracted from opium poppy

Semi-Synthetic

• Substances are derived chemically from a naturally occurring substance

• Ex. Heroin manufactured from morphine (that came from poppies); LSD manufactured from lysergic acid

Synthetic

• Substances that are totally artificial

• Ex. Amphetamines; Barbiturates; PCP; Oxycodone

Stimulants

• Elevate mood, give extra energy

• Often used for people who are sad or depressed

• Range in power from mild to strong

  • Ex. Caffeine and ephedrine (Legal, mild, not illicit drugs), Amphetamine and cocaine (Strong, often abused)

• Caffeine sometimes mixed with illegal drugs as an enhancing or cutting agent

Cutting Agents

• Contaminants = by-products of manufacturing process

• Adulterants = pharmacologically active ingredients added to give synergistic and antagonistic effects

• Diluents = inert substances added to bulk out the drug and decrease the amount of active ingredient

Amphetamine

• Stimulant

• Schedule 2

• Improve physical alertness and energy levels and can produce euphoria

• Chemical modification at R1 and R9 results in unlimited number of pharmacologically active compounds

• Grew out of desire to find a substitute for ephedrine

• Taken intravenously = Addictive

• Taken orally/smoked = Psychological dependence but no physical addiction

Cocaine

• Stimulant

• Naturally occurring substance that is found in the Erythoxylon coca plant

• Snorted = Psychological dependence but not physical addiction

• Crack = Addictive when smoked

Depressants

• Calm irritability and anxiety, reduce muscle coordination, impair judgement, and may induce sleep

• Ex. Barbiturates, Antianxiety/antipsychotic drugs, tranquilizers, methaqualone, alcohol

GHB

• Schedule 1 Drug; Schedule 3 when formulated in an FDA approved drug

• Stimulant and aphrodisiac effects

• Depressant

Rohypnol

• Odorless, colorless, tasteless benzodiazepine

• Schedule 4

• Depressant

Barbiturates

• Depressant

• Sedatives that can be taken orally or intravenously and used to treat anxiety and insomnia

• Based on compounds barbituric acid and thiobarbituric acid

• Grouped pharmacologically into 3 groups: Short, intermediate, and long acting

• Highly addictive and withdrawal can be difficult and dangerous

Hallucinogens

• No legitimate medical uses in US

• Most are naturally occurring substances

• Most are Schedule 1

• Most common = THC/Marijuana

• Alter normal perception, moods, and thought processes

Marijuana

• Schedule 1

• Hallucinogen

• 4-leaved plants with fluted stems consisting of 2 serrated and 2 rounded slender leaves

• Separated into many parts that vary widely in their THC content (Resin/Hashish, Hash oil)

• Smoked or ingested

LSD

• Hallucinogen

• Semi-synthetic, derived from ergot alkaloids from grain fungus

• Often dosed on art blotter paper, sugar cubes, or candy dots

• Most potent and famous hallucinogen

• Not addictive, psychological dependence is rare

Mescaline

• Hallucinogen

• Found in upper crown of peyote cactus

• Extracted as a sulfate

PCP

• Hallucinogen

• Schedule 2

• Dissociative anesthetic

Psilocybin and psilocin

• Hallucinogen

• Same chemical backbone as LSD

• Found in a variety of mushrooms

• Similar effects to LSD and mescaline

• Street test used to tentatively ID mushrooms is look for bluish color upon bruising or breakage

MDMA

• Hallucinogen

• Schedule 1

• Enhances self-awareness and decreases inhibitions

• Snorted, injected, smoked, or ingested

DMT

• Hallucinogen

• Produces euphoria and hallucinations with short duration

Ibogaine

• Hallucinogen

• Produced by a plant (Rook bark is ground and ingested)

Ketamine

• Hallucinogen

• Schedule 3

• Euphoria, trance, and hallucinations

• Very short acting

Salvia divinorum

• Hallucinogen

• Produced from Diviner’s sage

• Not currently controlled in US but restricted in many states

Opiates (Narcotics)

• Natural product, semi-synthetic, and synthetic drugs from the opium poppy

• Opium poppy source of the resin opium

• Highly addictive

• Produces both morphine and codeine that are then used to heroin

• Heroin - Schedule 1

• Morphine, methadone, oxycodone, fentanyl - Schedule 2

• Codeine - Schedule 5

Anabolic Steroids

• Synthetic compounds chemically related to male sex hormone testosterone

• Used for muscle building and to improve sport performance/physical appearance

• Schedule 3

New Psychoactive Substances (NPS)

• Schedule 1

• Recreational designer drugs

• Ex. Bath salts, Incense, Plant food, fertilizer, Khat, Kratom

• Many synthetic cathinone and cannabinoids

• Several placed under control after reported deaths

Drug Identification and Quantitation

• 3 Pronged approach = Color test, ATR FT-IR, and GC-MAS

• Similarities in structural characteristics and their derivatives can cause problems for analysts and make analysis difficult and time-consuming

• Knowing chemical form is useful for determining solvents

  • Acidic drugs with ionizable protons = Aspirin, ibuprofen, cocaine hydrochloride

  • Basic drugs with hydrogen acceptors = Caffeine, nicotine, crack cocaine

  • Ionic compounds = Cocaine hydrochloride (Soluble in water)

  • ATR FT-IR spectroscopy can be used to differentiate acid and base forms of cocaine