Criminalistics: Drugs Chapter 12 PDF

Criminalistics: An Introduction to Forensic Science Twelfth Edition Chapter 12 Drugs Copyright © 2018, 2015, 2011 Pearson Education, Inc. All Rights Reserved Introduction A drug can be defi...

Criminalistics: An Introduction to Forensic Science Twelfth Edition Chapter 12 Drugs Copyright © 2018, 2015, 2011 Pearson Education, Inc. All Rights Reserved Introduction 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 23 million people in the United States use illicit drugs. The nature of the drug experience can be approached from two distinctly different aspects of human behavior: 1. Psychological dependence: Conditioned use of a drug caused by underlying emotional needs 2. Physical dependence: Need for a drug that has been brought about by its regular use à characterized by withdrawal sickness when administration is abruptly stopped. Common Classification of Drugs of Abuse 1. Narcotics 2. Depressants 3. Stimulants 4. Hallucinogens Copyright © 2018, 2015, 2011 Pearson Education, Inc. All Rights Reserved  1. Psychological Dependence All types of repeated drug use creates psychological dependence Emotional factors playing part in drug dependence include: – Personal characteristics of the user, – His/her expectations about the drug experience, – Society's attitudes and possible responses – Settings in which the drug is used. The intensity of the psychological experience à difficult to define. – alcohol, heroin, and cocaine à lead to a high degree of involvement. – marijuana and codeine à lower potential for abuse. Copyright © 2018, 2015, 2011 Pearson Education, Inc. All Rights Reserved  2. Physical Dependence Physical dependence is defined as the physiological need for a drug brought about by its regular use. The desire to avoid withdrawal sickness, or abstinence syndrome, ultimately causes physical dependence or addiction. – Marijuana and cocaine are common drugs of abuse whose regular use does not lead to physical dependence. Copyright © 2018, 2015, 2011 Pearson Education, Inc. All Rights Reserved Table 12–1 The Potential of Some Commonly Abused Drugs to Produce Dependency with Regular Use Drug Psychological Physical Dependence Dependence 1. Narcotics - Morphine High Yes - Heroin High Yes - Methadone High Yes - Codeine Low Yes 2. Depressants - Barbiturates (short-acting) High Yes - Barbiturates (long-acting) Low Yes - Alcohol High Yes - Methaqualone (Quaalude) High Yes - Meprobamate (Miltown, Equanil) Moderate Yes - Diazepam (Valium) Moderate Yes - Chlordiazepoxide (Librium) Moderate Yes Copyright © 2018, 2015, 2011 Pearson Education, Inc. All Rights Reserved Table 12–1 (continued) The Potential of Some Commonly Abused Drugs to Produce Dependency with Regular Use Drug Psychological Physical Dependence Dependence 3. Stimulants Ø Amphetamines High ? Ø Cocaine High No Ø Caffeine Low No Ø Nicotine High Yes 4. Hallucinogens Ø Marijuana Low No Ø LSD No Low Ø Phencyclidine (PCP) No High Copyright © 2018, 2015, 2011 Pearson Education, Inc. All Rights Reserved  1. Narcotics Narcotic drugs are analgesics à relieve pain by a depressing action on the central nervous system. Their depressant effects impacts on blood pressure, pulse rate and breathing rate. Regular use of a narcotic lead to physical dependence. The most common source is opium, extracted from poppies. Figure 12–1 The opium poppy and its derivatives. Shown are the poppy plant, crude and smoking opium, codeine, heroin, and morphine. Copyright © 2018, 2015, 2011 Pearson Education, Inc. All Rights Reserved  1. Narcotics: Opiates Morphine is extracted from opium and is used to synthesize heroin. Heroin produces a "high" that is accompanied by drowsiness and a sense of well-being that generally last for three to four hours. Addicts frequently dissolve heroin in water by heating it in a spoon, and then inject in the skin. Codeine is also present in opium, but it is usually prepared synthetically from morphine. Figure 12–2 Heroin paraphernalia Copyright © 2018, 2015, 2011 Pearson Education, Inc. All Rights Reserved 1. Narcotics: Synthetic Opiates Synthetic opiates are not derived from opium OxyContin: not derived from opium or morphine – the active ingredient is oxycodone, – have the same physiological effects as do opium narcotics. – is prescribed to a million patients for treatment of chronic pain. Methadone is another well-known synthetic opiate à – pharmacologically related to heroin, – appears to eliminate the addict's desire for heroin while producing minimal side effects. Copyright © 2018, 2015, 2011 Pearson Education, Inc. All Rights Reserved 2. Depressants Depressants = substances used to depress the functions of the central nervous system. àcalm irritability and anxiety and may induce sleep. Includes: a. Alcohol (ethyl alcohol) enters the body's bloodstream and quickly travels to the brain, where it acts to suppress the brain's control of thought processes and muscle coordination. b. Barbiturates, or "downers," are normally taken orally and create a feeling of well-being, relax the body, and produce sleep. c. Antianxiety drugs produce a relaxing tranquility without impairment of high-thinking faculties or inducing sleep; e.g., Valium, Xanax. d. Substances that can be sniffed: Sniffing has immediate effects such as exhilaration, but impairs judgment and may cause liver, heart, and brain damage, or even death. e.g., airplane glue, model cement, or aerosol gas propellants such as freon Copyright © 2018, 2015, 2011 Pearson Education, Inc. All Rights Reserved 3. Stimulants Stimulants are substances taken to increase alertness or activity, followed by a decrease in fatigue and a loss of appetite. Includes a. Amphetamines, sometimes known as "uppers" or "speed," Amphetamine and methamphetamine, often injected intravenously, cause an initial "rush," followed by an intense feeling of pleasure à followed by a period of exhaustion and a prolonged Figure 12–5 Granular amphetamine beside a razor blade. period of depression b. Cocaine, which in its free-base form is known as crack. – Cocaine, extracted from the leaves of Erythroxylin coca, causes increased alertness and vigor, accompanied by the suppression of hunger, fatigue, and boredom. – Crack = cocaine mixed with baking soda and water, then heated à often smoked in glass pipes àstimulates the brain's pleasure center. Figure 12–6 Coca leaves and illicit forms of cocaine. Copyright © 2018, 2015, 2011 Pearson Education, Inc. All Rights Reserved 4. Hallucinogens: Marijuana Hallucinogens cause marked changes in normal thought processes, perceptions, and moods. Marijuana is the most widely used illicit drug. Ø is the most controversial because its long-term effects on health are still largely unknown. Ø preparation derived from the plant Cannabis Ø Its hallucinogenic properties comes from the Figure 12–3 Several rolled marijuana cigarettes lie on a pile of crushed dried chemical substance tetrahydrocannabinol, or marijuana leaves next to a tobacco cigarette. THC Ø THC content of Cannabis varies in different parts of the plant: decreasing in the following sequence: resin, flowers, leaves, with little THC in the stem, roots or seeds Ø THC-rich resin is known as hashish Ø does not cause physical dependency, but the Blocks of hashish and the marijuana leaf. risk of harm is in heavy, long-term use. Copyright © 2018, 2015, 2011 Pearson Education, Inc. All Rights Reserved  4. Other Hallucinogens Other hallucinogens include LSD, mescaline, PCP, psilocybin, and MDMA (Ecstasy). 1. LSD is synthesized from lysergic acid; Ø can cause hallucinations(last for 12 hours). 2. Phencyclidine, or PCP Ø often synthesized in clandestine laboratories Figure 12–7 Ecstasy, a popular club drug. Ø is often smoked, ingested, sniffed. Ø often mixed with other drugs, such as LSD, or amphetamine, and is sold as a powder ("angel dust"), capsule, or tablet. Ø first leads to feelings of strength and invulnerability; may turn to depression, violence, and suicide. Figure 12–4 Scene from a clandestine drug laboratory. Copyright © 2018, 2015, 2011 Pearson Education, Inc. All Rights Reserved  Drug-Control Laws The U.S. federal law known as the Controlled Substances Act will serve to illustrate a legal drug-classification system created to prevent and control drug abuse. This federal law establishes five schedules of classification for controlled dangerous substances on the basis of a drug's: – potential for abuse – potential for physical and psychological dependence – medical value Copyright © 2018, 2015, 2011 Pearson Education, Inc. All Rights Reserved Schedules of Classification Schedule I drugs have a high potential for abuse and have no currently accepted medical use such as heroin, marijuana, methaqualone, and LSD. Schedule II drugs have a high potential for abuse and have medical use with severe restrictions such as cocaine, PCP, and most amphetamine and barbiturate prescriptions. Schedule III drugs have less potential for abuse and a currently accepted medical use such as all barbiturate prescriptions not covered under Schedule II, such as codeine and anabolic steroids. Schedule IV drugs have a low potential for abuse and have a current medical use such as darvon, phenobarbital, and some tranquilizers such as diazepam (valium) and chlordiazepoxide (librium). Schedule V drugs must show low abuse potential and have medical use such as opiate drug mixtures that contain nonnarcotic medicinal ingredients. Copyright © 2018, 2015, 2011 Pearson Education, Inc. All Rights Reserved  Table 12–2 Control Mechanisms of the Controlled Substances Act Schedule Registration Record Manufacturing Distribution Dispensing Keeping Quotas Restrictions Limits I Required Separate Yes Order forms Research use only II Required Separate Yes Order forms Rx: written; no refills III Required Readily No, but some drugs Records required Rx: written or oral; Retrievable limited by schedule with Medical II quotas authorization refills up to five times in IV Required Readily Records required six months Retrievable No, but some drugs limited by schedule Rx: written or oral; II quotas with medical authorization refills V Required Records required up to five times in Readily six months Retrievable No, but some drugs limited by schedule Over-the-counter (Rx II quotas drugs limited to MD’s order; refills up to five times) Copyright © 2018, 2015, 2011 Pearson Education, Inc. All Rights Reserved  Collection and Preservation The field investigator has the responsibility of ensuring that the evidence is properly packaged and labeled for the laboratory. Generally common sense is the best guide, keeping in mind that the package must prevent the loss of the contents and/or cross-contamination. Often the original container in which the drug was seized will suffice. All packages must be marked with information that is sufficient to ensure identification by the officer in the future and establish the chain of custody. Copyright © 2018, 2015, 2011 Pearson Education, Inc. All Rights Reserved  Drug Identification The challenge or difficulty of forensic drug identification comes in selecting analytical procedures to ensure specific identification of a drug. This plan, or scheme of analysis, is divided into two phases. 1. Screening test à nonspecific and preliminary in nature to reduce the possibilities to a manageable number. 2. Confirmation test à a single test that specifically identifies a substance. Another consideration in selecting an analytical technique is the need for either a 1. Qualitative determination relates just to the identity of the materials 2. Quantitative determination. requires the determination of the percent composition of the components of a mixture. Copyright © 2018, 2015, 2011 Pearson Education, Inc. All Rights Reserved 1. Preliminary Analysis: Screening Tests Unknown substance may be any one of a thousand or more commonly encountered drugs àanalyst must use screening tests to reduce these possibilities to a small and manageable number. Color tests that will produce characteristic colors for illicit drugs: Figure 12–9 A field – Marquis Test – heroin and color test kit for marijuana. amphetamines – Duquenois-Levine – marijuana – Scott Test – cocaine – Dillie-Koppanyi – barbiturates Cocaine crystal formed in platinum chloride – Van Urk – LSD (400 ). Microcrystalline tests: studying the size and shape of crystals formed when the drug is mixed with specific reagents. a methamphetamine crystal formed in gold chloride (400 ) Copyright © 2018, 2015, 2011 Pearson Education, Inc. All Rights Reserved 2. Confirmational Determination Once this preliminary analysis is completed, a confirmational determination is pursued. Forensic chemists will use a specific test to identify a drug substance to the exclusion of all other known chemical substances. Typically used to specifically identify a drug substance are: 1. Chromatography: gas or thin layer 2. Infrared spectrophotometry or 3. Mass spectrometry Copyright © 2018, 2015, 2011 Pearson Education, Inc. All Rights Reserved  1. Chromatography Chromatography: technique of separating and tentatively identifying the components of a mixture. In chromatography, one phase is always made to move in one direction over a stationary or fixed phase. Materials that prefers the moving phase will slowly pull ahead and separate from substances that prefer to remain in the stationary phase. In this illustration of chromatography, the molecules represented by the blue balls have a greater affinity for the upper phase and hence will be pushed along at a faster rate by the moving air. Eventually, the two sets of molecules will separate from each other, completing the chromatographic process. Copyright © 2018, 2015, 2011 Pearson Education, Inc. All Rights Reserved a. Gas Chromatography In Gas Chromatography (GC): The moving phase = carrier gas à flows through a column. The stationary phase = thin film of liquid à contained within the column. The written record of this separation = a chromatogram. The time for a component to emerge from a GC column = retention time After a mixture has traversed the length of the column, it will emerge separated into its components. Basic gas chromatography. Copyright © 2018, 2015, 2011 Pearson Education, Inc. All Rights Reserved FIGURE 12–11 (a) An unknown mixture of barbiturates is identified by comparing its retention times to (b), a known mixture of barbiturates. Copyright © 2018, 2015, 2011 Pearson Education, Inc. All Rights Reserved b. Thin Layer Chromatography (TLC) Uses a solid stationary phase(coated onto a glass plate) and a mobile liquid phase to separate the components of the mixture. The liquid will slowly rise up the plate by capillary action causing the sample to become distributed between the stationary phase and the moving liquid phase. Because most compounds are colorless, the materials must be visualized by placing the plates under ultraviolet light or spraying the plate with a chemical reagent. The distance a spot travels up a thin-layer plate can be assigned a numerical value known as the Rf value. FIGURE 12–12 Copyright © 2018, 2015, 2011 Pearson Education, Inc. All Rights Reserved Figure 12–13 (a) The liquid phase begins to move up the stationary phase. (b) Liquid moves past the ink spot carrying the ink components up the stationary phase. (c) The moving liquid has separated the ink into its several components. Copyright © 2015, 2011, 2007 Pearson Education, Inc. All Rights Reserved Figure 12–14 Figure 12–15 Chromatograms of Thin-layer chromatogram known heroin (1) and quinine (2) of a marijuana extract. standards alongside suspect sample (3). Copyright © 2015, 2011, 2007 Pearson Education, Inc. All Rights Reserved  2. Spectrophotometry Substance can absorb visible light to produce color, many of the invisible radiations of the electromagnetic spectrum are likewise absorbed. Spectrophotometry, an important analytical tool, measures the quantity of radiation that a particular material absorbs as a function of wavelength and frequency. Copyright © 2018, 2015, 2011 Pearson Education, Inc. All Rights Reserved  The Spectrophotometer The spectrophotometer is the instrument used to measure and record the absorption spectrum of a chemical substance. The components of a spectrophotometer are a: – radiation source – monochromator or frequency selector – sample holder – detector convert electromagnetic radiation into electrical signal – recorder to produce a record of the signal Absorption spectra can be done in the visible, ultraviolet (UV) or infrared (IR) regions. Copyright © 2018, 2015, 2011 Pearson Education, Inc. All Rights Reserved UV Spectrophotometry Currently, most forensic laboratories use UV and IR spectrophotometers to characterize chemical compounds. The simplicity of the UV spectrum facilitates its use as a tool for determining a material's probable identity, although it may not provide a definitive result. The IR spectrum provides a far more complex pattern. Different materials always have distinctively different infrared spectra; each IR spectrum is therefore equivalent to a "fingerprint" of that substance. FIGURE 12–16 The ultraviolet FIGURE 12–17 spectrum of The ultraviolet heroin. spectrum of amphetamine. Copyright © 2018, 2015, 2011 Pearson Education, Inc. All Rights Reserved IR Spectrophotometry The IR spectrum provides a far more complex pattern Different materials always have distinctively different infrared spectra; each IR spectrum is therefore equivalent to a "fingerprint" of that substance. Figure 12–18a Infrared spectrum Figure 12–18b Infrared spectrum of of heroin secobarbital. Copyright © 2018, 2015, 2011 Pearson Education, Inc. All Rights Reserved 3. Mass Spectrometry In the mass spectrometer, a beam of high-energy electrons collide with a material, producing positively charged ions. These positive ions almost instantaneously decompose into numerous fragments, which are separated according to their masses. The unique feature of mass spectrometry is that under carefully controlled conditions, no two substances produce the same fragmentation pattern. FIGURE 12–20 (a) Mass spectrum of heroin. (b) Mass spectrum of cocaine. Copyright © 2018, 2015, 2011 Pearson Education, Inc. All Rights Reserved GC and Mass Spectrometry A direct connection between the GC column and the mass spectrometer allows each component to flow into the mass spectrometer as it emerges from the GC. The separation of a mixture's components is first accomplished by the GC. Then, fragmentation of each component by high-energy electrons in the mass spectrometer, will produce a distinct pattern, somewhat like a "fingerprint", of the substance being examined FIGURE 12–19: How GC/MS works. Left to right, the sample is separated into its components by the gas chromatograph, and then the components are ionized and identified by characteristic Copyright fragmentation patterns of the spectra © 2018, by produced 2015, the 2011 massPearson Education, Inc. All Rights Reserved spectrometer.