12 chapter Learning Objectives forensic toxicology S M I T H , J After studying this chapter you should be able to: O t
Explain how alcohol is absorbed into the bloodstream, transported throughout the body, and eliminated by oxidation S and excretion H t
Understand the process by which alcohol is excreted in the U breath via the lungs A t
Understand the concepts of infrared and fuel cell breath-testing devices for alcohol testing 6 t
Describe commonly employed field sobriety tests to assess 8 alcohol impairment KEY TERMS absorption acid alveoli anticoagulant artery base capillary excretion fuel cell detector metabolism oxidation pH scale preservative toxicologist vein t
List and contrast laboratory procedures for9measuring the concentration of alcohol in the blood 0 B preserve blood t
Relate the precautions to be taken to properly in order to analyze its alcohol content U t
Understand the significance of implied-consent laws and the Schmerber v. California and Missouri v. McNeely cases to traffic enforcement ISBN: 978-1-323-16745-8 t
Describe techniques that forensic toxicologists use to isolate and identify drugs and poisons t
Appreciate the significance of finding a drug in human tissues and organs to assessing impairment t
Understand the drug recognition expert program and how to coordinate it with a forensic toxicology result Criminalistics: An Introduction to Forensic Science, Eleventh Edition, by Richard Saferstein. Published by Prentice Hall. Copyright © 2015 by Pearson Education, Inc. 300 CHAPTER 12 It is no secret that in spite of the concerted efforts of law enforcement agencies to prevent distribution and sale of illicit drugs, thousands die every year from intentional or unintentional administration of drugs, and many more innocent lives are lost as a result of the erratic and frequently uncontrollable behavior of individuals under the influence of drugs. But one should not automatically attribute these occurrences to the wide proliferation of illicit-drug markets. For example, in the United States alone, drug manufacturers produce enough sedatives and antidepressants each year to provide every man, woman, and child with about 40 pills. All of the statistical and medical evidence shows ethyl alcohol, a legal over-the-counter drug, to be the most heavily abused drug in Western countries. Role of Forensic Toxicology Because the uncontrolled use of drugs has become a worldwide problem affecting all segments of society, the role of the toxicologist has taken on new and added significance. Toxicologists detect and identify drugs and poisonsS in body fluids, tissues, and organs. Their services are required not only in such legal institutions as crime laboratories and medical examiners’ offices; they M also reach into hospital laboratories—where the possibility of identifying a drug overdose may represent the difference betweenI life and death—and into various health facilities responsible for monitoring the intake of drugs and other toxic substances. Primary examples include performT to leaded paints or analyzing the urine of addicts enrolled in ing blood tests on children exposed methadone maintenance programs. H The role of the forensic toxicologist is limited to matters that pertain to violations of crimi, nal law. However, the responsibility for performing toxicological services in a criminal justice system varies considerably throughout the United States. In systems with a crime laboratory independent of the medical examiner, this responsibility may reside with one or the other or J may be shared by both. Some systems, however, take advantage of the expertise residing in governmental health department laboratories and assign this role to them. Nevertheless, whatever O facility handles this work, its caseload will reflect the prevailing popularity of the drugs that are S abused in the community. In most cases, this means that the forensic toxicologist handles numerH ous requests relating to the determination of the presence of alcohol in the body. All of the statistical and medical evidence shows that ethyl alcohol—a legal, over-the-counter U substance—is the most heavily abused drug in Western countries. Forty percent of all traffic A 17,500 fatalities per year, are alcohol related, along with more deaths in the United States, nearly than 2 million injuries each year requiring hospital treatment. This highway death toll, as well as the untold damage to life, limb, and property, shows the dangerous consequences of alcohol 6 of alcohol in the toxicologist’s work, we will begin by taking a abuse. Because of the prevalence closer look at how the body processes and responds to alcohol. 8 9 0 Toxicology of Alcohol The subject of alcohol analysisB immediately confronts us with the primary objective of forensic toxicology: to detect and isolateU drugs in the body so that their influence on human behavior can be determined. Knowing how the body metabolizes alcohol provides the key to understanding its effects on human behavior. This knowledge has also made possible the development of instruments that measure the presence and concentration of alcohol in individuals suspected of driving while under its influence. Metabolism of Alcohol The transformation of a chemical in the body to another chemical to facilitate its elimination from the body. Alcohol, or ethyl alcohol, is a colorless liquid normally diluted with water and consumed as a beverage. Alcohol appears in the blood within minutes after it has been consumed and slowly increases in concentration while it is being absorbed ABSORPTION AND DISTRIBUTION Criminalistics: An Introduction to Forensic Science, Eleventh Edition, by Richard Saferstein. Published by Prentice Hall. Copyright © 2015 by Pearson Education, Inc. ISBN: 978-1-323-16745-8 metabolism All chemicals that enter the body are eventually broken down by chemicals within the body and transformed into other chemicals that are easier to eliminate. This process of transformation, called metabolism, consists of three basic steps: absorption, distribution, and elimination. FORENSIC TOXICOLOGY from the stomach and the small intestine into the bloodstream. During the absorption phase, alcohol slowly enters the body’s bloodstream and is carried to all parts of the body. When the absorption period is completed, the alcohol becomes distributed uniformly throughout the watery portions of the body—that is, throughout about two-thirds of the body volume. Fat, bones, and hair are low in water content and therefore contain little alcohol, whereas alcohol concentration in the rest of the body is fairly uniform. After absorption is completed, a maximum alcohol level is reached in the blood, and the postabsorption period begins. Then the alcohol concentration slowly decreases until it reaches zero again. Many factors determine the rate at which alcohol is absorbed into the bloodstream, including the total time taken to consume the drink, the alcohol content of the beverage, the amount consumed, and the quantity and type of food present in the stomach at the time of drinking. With so many variables, it is difficult to predict just how long the absorption process will require. For example, beer is absorbed more slowly than an equivalent concentration of alcohol in water, apparently because of the carbohydrates in beer. Also, alcohol consumed on an empty stomach is absorbed faster than an equivalent amount of alcohol taken when there is food in the stomach (see Figure 12–1). S The longer the total time required for complete absorption to occur, the lower the M peak alcohol concentration in the blood. Depending on a combination of factors, maximum blood-alcohol concentration may not be reached until two or three I hours have elapsed from the time of consumption. However, under normal social drinking conditions, it takes anywhere from 30 to 90 minutes from the time of the final drinkTuntil the absorption process is completed. H 301 absorption Passage of alcohol across the wall of the stomach and small intestine into the bloodstream. , ELIMINATION As the alcohol is circulated by the bloodstream, the body begins to eliminate it. Alcohol is eliminated through two mechanisms: oxidation and excretion. Nearly all of the alcohol consumed (95 to 98 percent) is eventually oxidized to carbon dioxide and water. Oxidation takes J place almost entirely in the liver. There, in the presence of the enzyme alcohol dehydrogenase, the alcohol is converted into acetaldehyde and then to acetic acid. The acetic acid is subsequently O oxidized in practically all parts of the body, becoming carbon dioxide and water. Surine, and perspiration. Most The remaining alcohol is excreted, unchanged, in the breath, significant, the amount of alcohol exhaled in the breath is in direct H proportion to the concentration of alcohol in the blood. This observation has had a tremendous impact on the technology and ISBN: 978-1-323-16745-8 Blood alcohol—mg per 100 mL and % w/v U A 100 0.10 90 0.09 80 0.08 70 0.07 60 0.06 50 0.05 40 0.04 30 0.03 20 0.02 10 0.01 0 0.00 oxidation The combination of oxygen with other substances to produce new products. excretion Elimination of alcohol from the body in an unchanged state; alcohol is normally excreted in breath and urine. FIGURE 12–1 6 Blood-alcohol concentrations after ingestion of 2 ounces of 8 pure alcohol mixed in 8 ounces of water 9 (equivalent to about 5 ounces of 80-proof vodka). Empty stomach 0 B U Source: Courtesy U.S. Department of Transportation, Washington, D.C. Immediately after a meal of potatoes 0 1 2 3 4 5 6 Hours Criminalistics: An Introduction to Forensic Science, Eleventh Edition, by Richard Saferstein. Published by Prentice Hall. Copyright © 2015 by Pearson Education, Inc. inside the science Alcohol in the Circulatory System The extent to which an individual may be under the influence of alcohol is usually determined by measuring the quantity of alcohol present in the blood system. Normally, this is accomplished in one of two ways: (1) by direct chemical analysis of the blood for its alcohol content or (2) by measurement of the alcohol content of the breath. In either case, the significance and meaning of the results can better be understood when the movement of alcohol through the circulatory system is studied. Humans, like all vertebrates, have a closed circulatory system, which consists basically of a heart and numerous arteries, capillaries, and veins. An artery is a blood vessel carrying blood away from the heart, and a vein is a vessel carrying blood back toward the heart. Capillaries are tiny blood vessels that interconnect the arteries with the veins. The exchange of materials between the blood and the other tissues takes place across the thin walls of the capillaries. A schematic diagram of the circulatory system is shown in the figure. Ingestion and Absorption Let us now trace the movement of alcohol through the human circulatory system. After alcohol is ingested, it Lungs Pulmonary artery Vein Pulmonary vein RA LA RV LV Artery Simplified diagram of the human circulatory system. Dark vessels contain oxygenated blood; light vessels contain deoxygenated blood. I Aeration TThe respiratory system bridges with the circulatory sysHtem in the lungs, so that oxygen can enter the blood carbon dioxide can leave it. As shown in the fig, and ure, the pulmonary artery branches into capillaries ly- ing close to tiny pear-shaped sacs called alveoli. The contain about 250 million alveoli, all located at Jlungs the ends of the bronchial tubes. The bronchial tubes Oconnect to the windpipe (trachea), which leads up to mouth and nose (see the figure). At the surface of Sthe the alveolar sacs, blood flowing through the capillarHies comes in contact with fresh oxygenated air in the A rapid exchange now proceeds to take place Usacs. between the fresh air in the sacs and the spent air in Athe blood. Oxygen passes through the walls of the alveoli into the blood while carbon dioxide is discharged from the blood into the air (see the figure). 6If, during this exchange, alcohol or any other volatile is in the blood, it too will pass into the al8substance veoli. During breathing, the carbon dioxide and al9cohol are expelled through the nose and mouth, and alveoli sacs are replenished with fresh oxygenated 0the air breathed into the lungs, allowing the process to Bbegin all over again. U The distribution of alcohol between the blood and alveolar air is similar to the example of a gas dissolved in an enclosed beaker of water, as described on page 280. Here again, one can use Henry’s law to explain how the alcohol divides itself between the air and blood. Henry’s law may now be restated as follows: When a volatile chemical (alcohol) is dissolved in a liquid (blood) and is brought to equilibrium with air (alveolar breath), there is a fixed ratio between the concentration of the volatile compound (alcohol) in air (alveolar breath) and its concentration in the liquid (blood), and this ratio is constant for a given temperature. 302 Criminalistics: An Introduction to Forensic Science, Eleventh Edition, by Richard Saferstein. Published by Prentice Hall. Copyright © 2015 by Pearson Education, Inc. ISBN: 978-1-323-16745-8 Body tissues moves down the esophagus into the stomach. About 20 percent of the alcohol is absorbed through the stomach walls into the portal vein of 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 to the liver, where its destruction starts as the blood (carrying the alcohol) moves up to the heart. The blood enters the upper right chamber of the heart, called the right atrium (or auricle), and is forced into the lower right chamber of the heart, known as the right ventricle. Having returned to the heart from its circulation through the tissues, the blood at this time contains very little oxygen and much carbon diSoxide. Consequently, the blood must be pumped up the lungs, through the pulmonary artery, to be reMto plenished with oxygen. Bronchial tube Pulmonary vein Pulmonary artery Carbon dioxide Oxygen Carbon dioxide Oxygen Gas exchange in the lungs. Blood flows from the pulmonary artery into vessels that lie close to the walls of the alveoli sacs. Here the blood gives up its carbon dioxide and absorbs oxygen. The oxygenated blood leaves the lungs via the pulmonary vein and returns to the heart. The temperature at which the breath leaves the mouth is normally 34°C. At this temperature, experimental evidence has shown that the ratio of alcohol in the blood to alcohol in alveoli air is approximately 2,100 to 1. In other words, 1 milliliter of blood will contain nearly the same amount of alcohol as 2,100 milliliters of alveolar breath. Henry’s law thus becomes a basis for relating breath to blood-alcohol concentration. ISBN: 978-1-323-16745-8 Recirculation and Distribution Now let’s return to the circulating blood. After emerging from the lungs, the oxygenated blood is rushed back to the upper left chamber of the heart (left atrium) by the pulmonary vein. When the left atrium contracts, it forces the blood through a valve into the left ventricle, which is the lower left chamber of the heart. The left ventricle then pumps the freshly oxygenated blood into the arteries, which carry the blood to all parts of the body. Each of these arteries, in turn, branches into smaller arteries, which eventually connect with the numerous tiny capillaries embedded in the tissues. Here the alcohol moves out of the blood and into the tissues. The blood then runs from the capillaries into Alveolar sac S M I Alveolar sac T H , J O S H U A 6 8 9 0 B U tiny veins that fuse to form larger veins. These veins eventually lead back to the heart to complete the circuit. During absorption, the concentration of alcohol in the arterial blood is considerably higher than the concentration of alcohol in the venous blood. One typical study revealed a subject’s arterial blood-alcohol level to be 41 percent higher than the venous level 30 minutes after the last drink.1 This difference is thought to exist because of the rapid diffusion of alcohol into the body tissues from venous blood during the early phases of absorption. Because the administration of a blood test requires drawing venous blood from the arm, this test is clearly to the advantage of a subject who may still be in the absorption stage. However, once absorption is complete, the alcohol becomes equally distributed throughout the blood system. Nasal cavity Larynx Esophagus Trachea Bronchial tube Alveolar sac The respiratory system. The trachea connects the nose and mouth to the bronchial tubes. The bronchial tubes divide into numerous branches that terminate in the alveoli sacs in the lungs. 1 R. B. Forney et al., “Alcohol Distribution in the Vascular System: Concentrations of Orally Administered Alcohol in Blood from Various Points in the Vascular System and in Rebreathed Air during Absorption,” Quarterly Journal of Studies on Alcohol 25 (1964): 205. 303 Criminalistics: An Introduction to Forensic Science, Eleventh Edition, by Richard Saferstein. Published by Prentice Hall. Copyright © 2015 by Pearson Education, Inc. 304 CHAPTER 12 artery A blood vessel that carries blood away from the heart. vein A blood vessel that transports blood toward the heart. capillary A tiny blood vessel across whose walls exchange of materials between the blood and the tissues takes place; it receives blood from arteries and carries it to veins. alveoli Small sacs in the lungs through whose walls air and other vapors are exchanged between the breath and the blood. procedures used for blood-alcohol testing. The development of instruments to reliably measure breath for its alcohol content has made possible the testing of millions of people in a quick, safe, and convenient manner. The fate of alcohol in the body is therefore relatively simple—namely, absorption into the bloodstream, distribution throughout the body’s water, and finally, elimination by oxidation and excretion. The elimination, or “burn-off,” rate of alcohol varies in different individuals; 0.015 percent w/v (weight per volume) per hour is the average rate after the absorption process is complete.2 However, this figure is an average that varies by as much as 30 percent among individuals. Logically, the most obvious measure of intoxication would be the amount of liquor a person has consumed. Unfortunately, most arrests are made after the fact, when such information is not available to legal authorities; furthermore, even if these data could be collected, numerous related factors, such as body weight and the rate of alcohol’s absorption into the body, are so variable that it would be impossible to prescribe uniform standards that would yield reliable alcohol intoxication levels for all S individuals. Theoretically, for a true determination of the quantity of alcohol impairing an individual’s M normal body functions, it would be best to remove a portion of brain tissue and analyze it for I alcohol content. For obvious reasons, this cannot be done on living subjects. Consequently, toxicologists concentrate on the T blood, which provides the medium for circulating alcohol throughout the body, carrying it to all tissues including the brain. Fortunately, experimental H evidence supports this approach and shows blood-alcohol concentration to be directly proportional to the concentration ,of alcohol in the brain. From the medicolegal point of view, blood-alcohol levels have become the accepted standard for relating alcohol intake to its effect on the body. J As noted earlier, alcohol becomes concentrated evenly throughout the watery portions of the body. This knowledge can be useful for the toxicologist analyzing a body for the presence of alO cohol. If blood is not available, as in some postmortem situations, a medical examiner can select a water-rich organ or fluid—forSexample, the brain, cerebrospinal fluid, or vitreous humor—to estimate the body’s equivalent alcohol H level. BLOOD-ALCOHOL CONCENTRATION U A Testing for Intoxication From a practical point of view, drawing blood from veins of motorists suspected of being under the influence of alcohol is simply 6 not convenient. The need to transport each suspect to a location where a medically qualified person can draw blood would be costly and time consuming, 8 considering the hundreds of suspects that the average police department must test every year. The methods used must be designed to test hundreds of thousands of motorists annually, without 9 causing them undue physical harm or unreasonable inconvenience, and provide a reliable diagno0 sis that can be supported and defended within the framework of the legal system. This means that toxicologists have had to deviseB rapid and specific procedures for measuring a driver’s degree of alcohol intoxication that can be easily administered in the field. U Breath Testing for Alcohol 2 In the United States, laws that define blood-alcohol levels almost exclusively use the unit percent weight per volume—% w/v. Hence, 0.015 percent w/v is equivalent to 0.015 gram of alcohol per 100 milliliters of blood, or 15 milligrams of alcohol per 100 milliliters. Criminalistics: An Introduction to Forensic Science, Eleventh Edition, by Richard Saferstein. Published by Prentice Hall. Copyright © 2015 by Pearson Education, Inc. ISBN: 978-1-323-16745-8 The most widespread method for rapidly determining alcohol intoxication is breath testing. A breath tester is simply a device for collecting and measuring the alcohol content of alveolar breath. Alcohol is expelled, unchanged, in the breath of a person who has been drinking. A breath test measures the alcohol concentration in the pulmonary artery by measuring its concentration in alveolar breath. Thus, breath analysis provides an easily obtainable specimen along with a rapid and accurate result. FORENSIC TOXICOLOGY 305 Breath-test results obtained during the absorption phase may be higher than results obtained from a simultaneous analysis of venous blood. However, the former are more reflective of the concentration of alcohol reaching the brain and therefore more accurately reflect the effects of alcohol on the subject. Again, once absorption is complete, the difference between a blood test and a breath test should be minimal. BREATH-TEST INSTRUMENTS The first widely used instrument for measuring the alcohol content of alveolar breath was the Breathalyzer, developed in 1954 by R. F. Borkenstein, who was a captain in the Indiana State Police. Starting in the 1970s, the Breathalyzer was phased out and replaced by other instruments. Like the Breathalyzer, they assume that the ratio of alcohol in the blood to alcohol in alveolar breath is 2,100 to 1 at a mouth temperature of 34°C. In other words, 1 milliliter of blood contains nearly the same amount of alcohol as 2,100 milliliters of alveolar breath. Unlike the Breathalyzer, modern breath testers are free of chemicals. These devices include infrared light–absorption devices and fuel cell detectors (described in the following “Inside the Science” box). Infrared and fuel-cell-based breath testers are microprocessor controlled, so all an S operator has to do is to press a start button; the instrument automatically moves through M test results. These instrua sequence of steps and produces a readout of the subject’s ments also perform self-diagnostic tests to ascertain whetherI they are in proper operating condition. fuel cell detector A detector in which chemical reactions produce electricity. ISBN: 978-1-323-16745-8 T CONSIDERATIONS IN BREATH TESTING An important feature H of these instruments is that they can be connected to an external alcohol standard or simulator in the form of either a , liquid or a gas. The liquid simulator contains a known concentration of alcohol in water. It is heated to a controlled temperature and the vapor formed above the liquid is pumped into the instrument. Dry-gas standards typically consist of a known concentration of alcohol J mixed with an inert gas and compressed in cylinders. The external standard is automatically sampled by the breath-test instrument before and/or after the subject’s breath sample is taken O and recorded. Thus the operator can check the accuracy of the instrument against the known S alcohol standard. H that the unit captures the The key to the accuracy of a breath-testing device is to ensure alcohol in the alveolar (i.e., deep-lung) breath of the subject. This is typically accomplished by U programming the unit to accept no less than 1.1 to 1.5 liters of breath from the subject. Also, A a minimum breath flow rate the subject must blow for a minimum time (such as 6 seconds) with (such as 3 liters per minute). The breath-test instruments just described feature a slope detector, which ensures that the breath sample is alveolar, or deep-lung, breath. As the subject 6 blows into the instrument, the breath-alcohol concentration is continuously monitored. The instrument accepts a breath sample 8 only when consecutive measurements fall within a predetermined rate of change. This approach 9 relates to the true bloodensures that the sample measurement is deep-lung breath and closely alcohol concentration of the subject being tested. 0 A breath-test operator must take other steps to ensure that the breath-test result truly reflects the actual blood-alcohol concentration within the subject. A majorBconsideration is to avoid measuring “mouth alcohol” resulting from regurgitation, belching, or Urecent intake of an alcoholic beverage. Also, recent gargling with an alcohol-containing mouthwash can lead to the presence of mouth alcohol. As a result, the alcohol concentration detected in the exhaled breath is higher than the concentration in the alveolar breath. To avoid this possibility, the operator must not allow the subject to take any foreign material into his or her mouth for at least fifteen minutes before the breath test. Likewise, the subject should be observed not to have belched or regurgitated during this period. Mouth alcohol has been shown to dissipate after fifteen to twenty minutes from its inception. Measurement of independent breath samples taken within a few minutes of each other is another extremely important check of the integrity of the breath test. Acceptable agreement between the two tests taken minutes apart significantly reduces the possibility of errors caused by the operator, mouth alcohol, instrument component failures, and spurious electric signals. Criminalistics: An Introduction to Forensic Science, Eleventh Edition, by Richard Saferstein. Published by Prentice Hall. Copyright © 2015 by Pearson Education, Inc. 306 CHAPTER 12 inside the science Breath inlet Infrared radiation source Sample chamber Breath inlet (b) J O S H U A (a) An infrared breath-testing instrument—the Data Master DMT. (b) A subject blowing into the DMT breath tester. 6 8 9 0 B U Breath flows into chamber Filter Detector Infrared light beamed through Breath chamber. Alcohol in breath outlet absorbs some infrared light. Sample chamber Detector Criminalistics: An Introduction to Forensic Science, Eleventh Edition, by Richard Saferstein. Published by Prentice Hall. Copyright © 2015 by Pearson Education, Inc. ISBN: 978-1-323-16745-8 Infrared radiation source Breath outlet S M I (a) T H , Courtesy Intoximeters, Inc., St. Louis, MO, www.intox.com In principle, infrared instruments operate no differently than the spectrophotometers described in Chapter 11. An evidential testing instrument that incorporates the principle of infrared light absorption is shown in Figure 1. Any alcohol present in the subject’s breath flows into the instrument’s breath chamber. As shown in Figure 2, a beam of infrared light is aimed through the chamber. A filter is used to select a wavelength of infrared light at which alcohol will absorb. As the infrared light passes through the chamber, it interacts with the alcohol and causes the light to decrease in intensity. The decrease in light intensity is measured by a photoelectric detector that gives a signal proportional to the concentration of alcohol present in the breath sample. This information is processed by an electronic microprocessor, and the percent blood-alcohol concentration is displayed on a digital readout. Also, the blood-alcohol level is printed on a card to produce a permanent record of the test result. Most infrared breath testers aim a second infrared beam into the same chamber to check for acetone or other chemical interferences on the breath. If the instrument detects differences in the relative response of the two infrared beams that does not conform to ethyl alcohol, the operator is immediately informed of the presence of an “interferant.” Courtesy Intoximeters, Inc., St. Louis, MO, www.intox.com Infrared Light Absorption FORENSIC TOXICOLOGY Breath inlet Infrared radiation source Infrared radiation source Breath outlet Sample chamber Breath inlet Filter selects wavelength of IR light at which alcohol absorbs Detector Breath outlet Sample chamber Breath inlet 307 Breath outlet S M I Detector converts infrared T light to an electrical signal proportional to the alcohol H content in breath. , J O S H Infrared Sample chamber Detector radiation U source A Schematic diagram of an infrared breath-testing instrument. Breath-alcohol content is converted into a blood-alcohol concentration and displayed on a digital readout. ISBN: 978-1-323-16745-8 6 8 9 Field Sobriety Testing 0 A police officer who suspects that an individual is under the influence of alcohol usually B to submit to an evidential conducts a series of preliminary tests before ordering the suspect breath or blood test. These preliminary, or field sobriety, tests Uare normally performed to ascertain the degree of the suspect’s physical impairment and whether an evidential test is justified. Field sobriety tests usually consist of a series of psychophysical tests and a preliminary breath test (if such devices are authorized and available for use). A portable handheld roadside breath tester is shown in Figure 12–2. This pocket-sized device weighs 5 ounces and uses a fuel cell to measure the alcohol content of a breath sample. The fuel cell absorbs the alcohol from the breath sample, oxidizes it, and produces an electrical current proportional to the breath-alcohol content. This instrument Figure 12–2 can typically perform for years before the fuel cell needs to be replaced. Its been approved for use as an evidential breath tester by the National Highway Traffic Safety Administration. Horizontal-gaze nystagmus, walk and turn, and the one-leg stand constitute a series of reliable and effective psychophysical tests. Horizontal-gaze nystagmus is an involuntary jerking of the eye as it moves to the side. A person experiencing nystagmus is usually unaware Criminalistics: An Introduction to Forensic Science, Eleventh Edition, by Richard Saferstein. Published by Prentice Hall. Copyright © 2015 by Pearson Education, Inc. Courtesy Intoximeters, Inc., St. Louis, MO, www.intox.com CHAPTER 12 Courtesy Intoximeters, Inc., St. Louis, MO, www.intox.com 308 (b) (a) S FIGURE 12–2 M tester device. (a) The Alco-Sensor FST. (b) A subject blowing into the roadside The Fuel Cell 6 8 9 0 B U Breath e– e– e– A fuel cell converts energy arising from a chemical reaction into electrochemical energy. A typical fuel cell consists of two platinum electrodes separated by an acid- or base-containing porous membrane. A platinum wire connects the electrodes and allows a current to flow between them. In the alcohol fuel cell, one of the electrodes is positioned to come into contact with a subject’s breath sample. If alcohol is present in the breath, a reaction at the electrode’s surface converts the alcohol to acetic acid. One by-product of this conversion is free electrons, which flow through the connecting wire to the opposite electrode, where they interact with atmospheric oxygen to form water (see the figure). The fuel cell also requires the migration of hydrogen ions across the acidic porous membrane to complete the circuit. The strength of the current flow between the two electrodes is proportional to the concentration of alcohol in the breath. J O S H U A e– e– e– inside the science I T H , Acetic acid Oxygen H2O Alcohol Outlet Porous membrane A fuel cell detector in which chemical reactions are used to produce electricity. Criminalistics: An Introduction to Forensic Science, Eleventh Edition, by Richard Saferstein. Published by Prentice Hall. Copyright © 2015 by Pearson Education, Inc. ISBN: 978-1-323-16745-8 that the jerking is happening and is unable to stop or control it. The subject being tested is asked to follow a penlight or some other object with his or her eye as far to the side as the eye can go. The more intoxicated the person is, the less the eye has to move toward the side before jerking or nystagmus begins. Usually, when a person’s blood-alcohol concentration is in the range of 0.10 percent, the jerking begins before the eyeball has moved 45 degrees to the side FORENSIC TOXICOLOGY 309 FIGURE 12–3 When a person’s blood-alcohol level is in the range of 0.10 percent, jerking of the eye during the horizontal-gaze nystagmus test begins before the eyeball has moved 45 degrees to the side. Eye lo o straig king ht ah ead 45° (see Figure 12–3). Higher blood-alcohol concentration causes jerking at smaller angles. Also, if the suspect has taken a drug that also causes nystagmus (such as phencyclidine, barbiturates, and other depressants), the nystagmus onset angle may occur much S earlier than would be expected from alcohol alone. M testing the subject’s abilWalk and turn and the one-leg stand are divided-attention tasks, ity to comprehend and execute two or more simple instructions I at one time. The ability to understand and simultaneously carry out more than two instructions is significantly affected by T to maintain balance while increasing blood-alcohol levels. Walk and turn requires the suspect standing heel-to-toe and at the same time listening to and comprehending the test instructions. H During the walking stage, the suspect must walk a straight line, touching heel-to-toe for nine steps, then turn around on the line and repeat the process. The ,one-leg stand requires the suspect to maintain balance while standing with heels together listening to the instructions. During the balancing stage, the suspect must stand on one foot while holding the other foot several J must count out loud during inches off the ground for 30 seconds; simultaneously, the suspect the 30-second time period. O S H Analysis of Blood for Alcohol U Gas chromatography is the approach most widely used by forensic toxicologists for determining A alcohol can be separated alcohol levels in blood. Under proper gas chromatographic conditions, 8 9 0 B U FID1 A, (112712A\019F1901.D) pA 175 1.228- Ethanol 150 125 100 75 50 2.106- Internal Standard from other volatile substances in the blood. By comparing the resultant alcohol peak area to ones obtained from known blood-alcohol standards, the investigator can calculate the alcohol level 6 with a high degree of accuracy (see Figure 12–4). ISBN: 978-1-323-16745-8 25 0 0.5 1 1.5 2 2.5 min FIGURE 12–4 A gas chromatogram showing ethyl alcohol (ethanol) in whole blood. Criminalistics: An Introduction to Forensic Science, Eleventh Edition, by Richard Saferstein. Published by Prentice Hall. Copyright © 2015 by Pearson Education, Inc. 310 CHAPTER 12 Another procedure for alcohol analysis involves the oxidation of alcohol to acetaldehyde. This reaction is carried out in the presence of the enzyme alcohol dehydrogenase and the coenzyme nicotin-amide-adenine dinucleotide (NAD). As the oxidation proceeds, NAD is converted into another chemical species, NADH. The extent of this conversion is measured by a spectrophotometer and is related to alcohol concentration. This approach to blood-alcohol testing is normally associated with instruments used in clinical or hospital settings. Instead, forensic laboratories normally use gas chromatography for determining blood-alcohol content. Collection and Preservation of Blood anticoagulant A substance that prevents coagulation or clotting of blood. preservative A substance that stops the growth of microorganisms in blood. Blood must always be drawn under medically acceptable conditions by a qualified individual. A nonalcoholic disinfectant should be applied before the suspect’s skin is penetrated with a sterile needle or lancet. It is important to eliminate any possibility that an alcoholic disinfectant could inadvertently contribute to a falsely high blood-alcohol result. Nonalcoholic disinfectants such as aqueous benzalkonium chloride (Zepiran), aqueous mercuric chloride, or povidone-iodine Sthis purpose. (Betadine) are recommended for Once blood is removed from Man individual, it is best preserved sealed in an airtight container after adding an anticoagulant and a preservative. The blood should be stored in a refrigerator until delivery to the toxicology Ilaboratory. The addition of an anticoagulant, such as EDTA or potassium oxalate, prevents clotting; T a preservative, such as sodium fluoride, inhibits the growth of microorganisms capable of destroying alcohol. H One study performed to determine the stability of alcohol in blood removed from living individuals found that the most significant factors affecting alcohol’s stability in blood are storage , temperature, the presence of a preservative, and the length of storage.3 Not a single blood specimen examined showed an increase in alcohol level with time. Failure to keep the blood refrigerated or to add sodium fluoride resulted in a substantial decline in alcohol concentration. Longer J storage times also reduced blood-alcohol levels. Hence, failure to adhere to any of the proper O works to the benefit of the suspect and to the detriment of preservation requirements for blood society. S The collection of postmortem blood samples for alcohol-level determinations requires added precautions. Ethyl alcohol mayH be generated in the body of a deceased individual as a result of bacterial action. Therefore, it isUbest to collect a number of blood samples from different body sites. For example, blood may be removed from the heart and from the femoral vein (in the leg) A sample should be placed in a clean, airtight container containand cubital vein (in the arm). Each ing an anticoagulant and sodium fluoride preservative and should be refrigerated. Blood-alcohol levels can be attributed solely to alcohol consumption if they are nearly similar in all blood 6 person. As an alternative to blood collection, the collection of samples collected from the same vitreous humor and urine is recommended. Vitreous humor and urine usually do not experience 8 any significant postmortem ethyl alcohol production. 9 0 Alcohol and the B Law Constitutionally, every state inU the United States is charged with establishing and administer- ing statutes regulating the operation of motor vehicles. Although such an arrangement might encourage diverse laws defining permissible blood-alcohol levels, this has not been the case. Both the American Medical Association and the National Safety Council have exerted considerable influence in persuading the states to establish uniform and reasonable blood-alcohol standards. Between 1939 and 1964, 39 states and the District of Columbia enacted legislation that followed the recommendations of the American Medical Association and the National Safety Council in specifying that a person with a blood-alcohol concentration in excess of 0.15 percent w/v 3 G. A. Brown et al., “The Stability of Ethanol in Stored Blood,” Analytica Chemica Acta 66 (1973): 271. Criminalistics: An Introduction to Forensic Science, Eleventh Edition, by Richard Saferstein. Published by Prentice Hall. Copyright © 2015 by Pearson Education, Inc. ISBN: 978-1-323-16745-8 Blood-Alcohol Laws FORENSIC TOXICOLOGY 311 was to be considered under the influence of alcohol.4 However, continued experimental studies have since shown a clear correlation between drinking and driving impairment for blood-alcohol levels much below 0.15 percent w/v. As a result of these studies, in 1960 the American Medical Association and in 1965 the National Safety Council recommended lowering the presumptive level at which an individual was considered to be under the influence of alcohol to 0.10 percent w/v. In 2000, U.S. federal law established 0.08 percent as the per se blood-alcohol level, meaning that any individual meeting or exceeding this blood-alcohol level shall be deemed intoxicated. No other proof of alcohol impairment is necessary. The 0.08 percent level applies only to noncommercial drivers, as the federal government has set the maximum allowable blood-alcohol concentration for commercial truck and bus drivers at 0.04 percent. Several Western countries have also set 0.08 percent w/v as the blood-alcohol level above which it is an offense to drive a motor vehicle. Those countries include Canada, Italy, Switzerland, and the United Kingdom. Finland, France, Germany, Ireland, Japan, the Netherlands, and Norway have a 0.05 percent limit. Australian states have adopted a 0.05 percent blood-alcohol concentration level. Sweden has lowered its blood-alcohol concentration limit to 0.02 percent. As shown in Figure 12–5, one is about four times as likely to S become involved in an automobile accident at the 0.08 percent level as a sober individual. At the 0.15 percent level, the chances Mcompared to a sober driver. are 25 times as much for involvement in an automobile accident The reader can estimate the relationship of blood-alcohol levels to I body weight and the quantity of 80-proof liquor consumed by referring to Figure 12–6. T Constitutional Issues H The Fifth Amendment to the U.S. Constitution guarantees all citizens protection against self, incrimination—that is, against being forced to make an admission that would prove one’s own guilt in a legal matter. To prevent a person’s refusal to take a test for alcohol intoxication on the constitutional grounds of self-incrimination, the National Highway Traffic Safety Administration J (NHTSA) recommended an “implied consent” law. By 1973, all the states had complied with this O vehicle on a public highway recommendation. In accordance with this statute, operating a motor automatically carries with it the stipulation that the driver must either submit to a test for alcoS hol intoxication if requested or lose his or her license for some designated period—usually six H months to one year. U A 30 8 9 0 B U 20 15 10 5 ISBN: 978-1-323-16745-8 About 25 times as much 6 as normal at 0.15% 1 .00 About 4 times as much as normal at 0.08% .04 .08 .12 .16 Blood-alcohol concentration .20 U.S. Department of Transportation Relative chances of a crash 25 FIGURE 12–5 Diagram of increased driving risk in relation to blood-alcohol concentration. 4 0.15 percent w/v is equivalent to 0.15 grams of alcohol per 100 milliliters of blood, or 150 milligrams per 100 milliliters. Criminalistics: An Introduction to Forensic Science, Eleventh Edition, by Richard Saferstein. Published by Prentice Hall. Copyright © 2015 by Pearson Education, Inc. 312 CHAPTER 12 How to Tell What Your Blood Alcohol Level Is after Drinking Body Ounces of Maximum weight (lb.) 240 230 220 210 200 190 80-proof liquor consumed blood-alcohol concentration (% by weight) Body weight (lb.) Ounces of 80-proof liquor consumed 0.20 0.19 0.18 0.17 180 16 15 14 13 12 11 10 170 9 0.15 160 8 0.14 180 16 15 14 13 12 11 10 150 7 0.13 170 9 140 6 160 8 150 7 140 6 0.16 240 230 220 210 200 190 0.12 130 5 0.11 120 4 110 100 3 2 “Empty stomach” S M I T H , 130 0.10 0.08 0.12 0.11 0.10 0.08 0.07 110 3 0.06 0.05 0.04 0.07 “Full stomach” 0.06 0.13 5 4 100 0.14 0.09 120 0.09 Maximum blood-alcohol concentration (% by weight) 0.20 0.19 0.18 0.17 0.16 0.15 2 0.03 0.05 J FIGURE 12–6 O To use this diagram, lay a straightedge across your weight and the number of ounces S of liquor you’ve consumed on an empty or full stomach. The point where the edge hits Hmaximum blood-alcohol level. The rate of elimination of the right-hand column is your alcohol from the bloodstream Uis approximately 0.015 percent per hour. Therefore, to calculate your actual blood-alcohol level, subtract 0.015 from the number in the rightA the start of drinking. hand column for each hour from Source: U.S. Department of Transportation. 6 5 384 U.S. 757 (1966). 6 133 S. Ct. 932 (2013). Criminalistics: An Introduction to Forensic Science, Eleventh Edition, by Richard Saferstein. Published by Prentice Hall. Copyright © 2015 by Pearson Education, Inc. ISBN: 978-1-323-16745-8 In 1966, the Supreme Court, in Schmerber v. California,5 addressed the constitutionality of collecting a blood specimen 8 for alcohol testing, as well as for obtaining other types of physical evidence from a suspect without 9 consent. While being treated at a Los Angeles hospital for injuries sustained in an automobile collision, Schmerber was arrested for driving under the 0 took a blood sample from Schmerber at the direction of the influence of alcohol. A physician police, over the objection of the Bdefendant. On appeal to the U.S. Supreme Court, the defendant argued that his privilege against self-incrimination had been violated by the introduction of the results of the blood testU at his trial. The Court ruled against the defendant, reasoning that the Fifth Amendment only prohibits compelling a suspect to give “testimonial” evidence that may be self-incriminating; being compelled to furnish “physical” evidence, such as fingerprints, photographs, measurements, and blood samples, the Court ruled, was not protected by the Fifth Amendment. The Court also addressed the question of whether Schmerber was subjected to an unreasonable search and seizure by the taking of a blood specimen without a search warrant. In the 1966 decision, the Court upheld the blood removal, reasoning that the natural body elimination of alcohol created an emergency situation allowing for a warrantless search. The Court revisited this issue once again forty-seven years after Schmerber in the case of Missouri v. McNeely.6 FORENSIC TOXICOLOGY 313 Here, the Court addressed the issue as to whether the natural elimination of alcohol in blood categorically justifies a warrantless intrusion. The Court noted that advances in communication technology now allow police to obtain warrant quickly by phone, e-mail, or teleconferencing. In those drunk-driving investigations where police officers can reasonably obtain a warrant before a blood sample can be drawn without significantly undermining the efficacy of the search, the Fourth Amendment mandates that they do so. . . . In short, while the natural dissipation of alcohol in the blood may support a finding of exigency in a specific case, as it did in Schmerber, it does not do so categorically. Whether a warrantless blood test of a drunk-driving suspect is reasonable must be determined case by case based on the totality of the circumstances. S M he or she encounters an Once the forensic toxicologist ventures beyond the analysis of alcohol, encyclopedic maze of drugs and poisons. Even a cursory discussion I of the problems and handicaps imposed on toxicologists is enough to develop a sense of appreciation for their accomplishT ments and ingenuity. H Challenges Facing the Toxicologist , The toxicologist is presented with body fluids and/or organs and asked to examine them for the WEBEXTRA 12.1 Calculate Your Blood-Alcohol Level WEBEXTRA 12.2 See How Alcohol Affects Your Behavior ISBN: 978-1-323-16745-8 The Role of the Toxicologist toxicologist An individual charged with the responsibility of detecting and identifying the presence of drugs and poisons in body fluids, tissues, and organs. presence of drugs and poisons. If he or she is fortunate, which is not often, some clue to the type of toxic substance present may develop from the victim’s symptoms, a postmortem pathoJ logical examination, an examination of the victim’s personal effects, or the nearby presence of empty drug containers or household chemicals. Without such O supportive information, the toxicologist must use general screening procedures with the hope of narrowing thousands of S possibilities to one. H If this task does not seem monumental, consider that the toxicologist is not dealing with drugs at the concentration levels found in powders and pills. By the time a drug specimen reaches U the toxicology laboratory, it has been dissipated and distributed throughout the body. Whereas A to work with, the toxicolothe drug analyst may have gram or milligram quantities of material gist must be satisfied with nanogram or at best microgram amounts, acquired only after careful extraction from body fluids and organs. 6 no one can appreciate this Furthermore, the body is an active chemistry laboratory, and observation more than a toxicologist. Few substances enter and completely leave the body in the 8 same chemical state. The drug that is injected is not always the substance extracted from the body 9 or metabolizes the chemical tissues. Therefore, a thorough understanding of how the body alters structure of a drug is essential in detecting its presence. 0 It would, for example, be futile and frustrating to search exhaustively for heroin in the huB man body. This drug is almost immediately metabolized to morphine on entering the bloodstream. Even with this information, the search may still prove impossible unless the examiner U also knows that only a small percentage of morphine is excreted unchanged in urine. For the most part, morphine becomes chemically bonded to body carbohydrates before elimination in urine. Thus, successful detection of morphine requires that its extraction be planned in accordance with a knowledge of its chemical fate in the body. Another example of how one needs to know how a drug metabolizes itself in the body is exemplified by the investigation of the death of Anna Nicole Smith. In her case, the sedative chloral hydrate was a major contributor to her death, and its presence was detected by its active metabolite, trichloroethanol (see the following case files box). Last, when and if the toxicologist has surmounted all of these obstacles and has finally detected, identified, and quantitated a drug or poison, he or she must assess the substance’s toxicity. Fortunately, there is published information relating to the toxic levels of most drugs; however, when such data are available, their interpretation must assume that the victim’s physiological behavior agrees with that of the subjects of previous studies. In some cases, such an assumption Criminalistics: An Introduction to Forensic Science, Eleventh Edition, by Richard Saferstein. Published by Prentice Hall. Copyright © 2015 by Pearson Education, Inc. CHAPTER 12 Michael Jackson: The Demise of a Superstar A call to 911 had the desperate tone of urgency. The voice of a young man implored an ambulance to hurry to the home of pop star Michael Jackson. The unconscious performer was in cardiac arrest and was not responding to CPR. The 50-year-old Jackson was pronounced dead upon arrival at a regional medical center. When the initial autopsy results revealed no signs of foul play, rumors immediately began to swirl around aS drug-related death. News media coverage showed investigators carrying bags full of drugs and syringes out of the JacksonM residence. So it came as no surprise that the forensic toxicologyI report accompanying Jackson’s autopsy showed that the enterT tainer had died of a drug overdose. Apparently Jackson had become accustomed to receiving sedatives to help him sleep. Early on the morning of hisH death, his physician gave Jackson a tab of Valium. At 2 a.m., he, administered the sedative lorazepam, and at 3 a.m. the physician administered another sedative, midazolam. Those drugs were administered again at 5 a.m. and 7:30 a.m., but Jackson J still was unable to sleep. Finally, at about 10:40 a.m., Jackson’s doctor gave him 25 milligrams of propofol, at which pointO Justin Sullivan/AP Images case files 314 Michael Jackson Jackson went to sleep. Propofol is a powerful sedative used primarily in the maintenance of surgical anesthesia. All of the drugs administered to Jackson were sedatives, which can act in concert to depress the activities of the central nervous system. Therefore, it comes as no surprise that this drug cocktail resulted in cardiac arrest and death. S H U may not be entirely valid without knowing the subject’s case history. No experienced toxicologist would be surprised to find A an individual tolerating a toxic level of a drug that would have killed most other people. Collection and Preservation of Toxicological Evidence 6 Criminalistics: An Introduction to Forensic Science, Eleventh Edition, by Richard Saferstein. Published by Prentice Hall. Copyright © 2015 by Pearson Education, Inc. ISBN: 978-1-323-16745-8 Toxicology is made infinitely 8 easier once it is recognized that the toxicologist’s capabilities are directly dependent on the input received from the attending physician, medical examiner, and police investigator. It is a9tribute to forensic toxicologists, who must often labor under conditions that do not afford 0 such cooperation, that they can achieve such a high level of proficiency. Generally, with a deceased B person, the medical examiner decides what biological specimens must be shipped to the toxicology U laboratory for analysis. However, a living person suspected of being under the influence of a drug presents a completely different problem, and few options are available. When possible, both blood and urine are taken from any suspected drug user. The entire urine void is collected and submitted for toxicological analysis. Preferably, two consecutive voids should be collected in separate specimen containers. When a licensed physician or registered nurse is available, a sample of blood should also be collected. The amount of blood taken depends on the type of examination to be conducted. Comprehensive toxicological tests for drugs and poisons can conveniently be carried out on a minimum of 10 cc of blood. A determination solely for the presence of alcohol will require much less—approximately 5 cc of blood. However, many therapeutic drugs, such as tranquilizers and barbiturates, when taken in combination with a small, nonintoxicating amount of alcohol, produce behavioral patterns resembling alcohol intoxication. For this reason, the toxicologist must be given an adequate amount of blood so he or she will 315 Accidental Overdose: The Tragedy of Anna Nicole Smith Rumors exploded in the media when former model, Playboy playmate, reality television star, and favorite tabloid subject Anna Nicole Smith was found unconscious in her hotel room at the Seminole Hard Rock Hotel and Casino in Hollywood, Florida. She was taken to Memorial Legal Hospital, where she was declared dead at age 39. Analysis of Smith’s blood postmortem revealed an array of prescribed medications. Most S pronounced was a toxic level of the sedative chloral hydrate. M A part of the contents of the toxicology report from Smith’s autopsy are shown here. I Although many of the drugs present were detected at T levels consistent with typical doses of the prescribed medications, it was their presence in combination with chloral hyH drate that exacerbated the toxic level of chloral hydrate. The lethal combination of these prescription drugs caused failure , of both her circulatory and respiratory systems and resulted in her death. The investigators determined that the overdose of chloral hydrate and other drugs was accidental and not a J suicide. This was due to the nonexcessive levels of most of the prescription medications and the discovery of a significant O amount of chloral hydrate still remaining in its original conS tainer; had she intended to kill herself, she would have likely downed it all. Anna Nicole Smith was a victim of accidental H overmedication. U A Manuel Balce Cenet/Landov Media case files FORENSIC TOXICOLOGY Anna Nicole Smith Final Pathological Diagnoses I. Acute Combined Drug Intoxication A. Toxic/legal drug: Chloral Hydrate (Noctec) 1. Trichloroethanol (TCE) 75 mg/L (active metabolite) 2. Trichloroacetic acid (TCA) 85 mg/L (inactive metabolite) B. Therapeutic drugs: 1. Diphenhydramine (Benadryl) 0.11 mg/L 2. Clonazepam (Klonopin) 0.04 mg/L 3. Diazepam (Valium) 0.21 mg/L 4. Nordiazepam (metabolite) 0.38 mg/L 5. Temazepam (metabolite) 0.09 mg/L 6. Oxazepam 0.09 mg/L 7. Lorazepam 0.022 mg/L C. Other noncontributory drugs present (atropine, topiramate, ciprofloxacin, acetaminophen) have the option of performing a comprehensive analysis for 6 drugs in cases of low alcohol concentrations. 8 9 For the toxicologist, the upsurge in drug use and abuse has meant0that the overwhelming majority of fatal and nonfatal toxic agents are drugs. Not surprisingly, a relatively small number of B drugs—namely, those discussed in Chapter 11—comprise nearly all the toxic agents encounUfor 90 percent or more of the tered. Of these, alcohol, marijuana, and cocaine normally account Techniques Used in Toxicology ISBN: 978-1-323-16745-8 drugs encountered in a typical toxicology laboratory. ACIDS AND BASES Like the drug analyst, the toxicologist must devise an analytical scheme to detect, isolate, and identify a toxic substance. The first chore is to selectively remove and isolate drugs and other toxic agents from the biological materials submitted as evidence. Because drugs constitute a large portion of the toxic materials found, a good deal of effort must be devoted to their extraction and detection. The procedures are numerous, and a useful description of them would be too detailed for this text. We can best understand the underlying principle of drug extraction by observing that many drugs fall into the categories of acids and bases. Although several definitions exist for these two classes, a simple one states that an acid is a compound that sheds a hydrogen ion (or a hydrogen atom minus its electron) with reasonable acid A compound capable of donating a hydrogen ion (H1) to another compound. base A compound capable of accepting a hydrogen ion (H1). Criminalistics: An Introduction to Forensic Science, Eleventh Edition, by Richard Saferstein. Published by Prentice Hall. Copyright © 2015 by Pearson Education, Inc. 316 CHAPTER 12 pH scale A scale used to express the basicity or acidity of a substance; a pH of 7 is neutral, whereas lower values are acidic and higher values are basic. ease. Conversely, a base is a compound that can pick up a hydrogen ion shed by an acid. The idea of acidity and basicity can be expressed in terms of a simple numerical value that relates to the concentration of the hydrogen ion (H1) in a liquid medium such as water. Chemists use the pH scale to do this. This scale runs from 0 to 14: pH 5 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 ← Increasing acidity—Neutral—Increasing basicity → Normally, water is neither acidic nor basic—in other words, it is neutral, with a pH of 7. However, when an acidic substance—for example, sulfuric acid or hydrochloric acid—is added to the water, it adds excess hydrogen ions, and the pH value becomes less than 7. The lower the number, the more acidic the water. Similarly, when a basic substance—for example, sodium hydroxide or ammonium hydroxide—is added to water, it removes hydrogen ions, thus making water basic. The more basic theS water, the higher its pH value. By controlling the pH of a water solution into which blood, urine, or tissues are dissolved, Mcontrol the type of drug that is recovered. For example, acidic the toxicologist can conveniently drugs are easily extracted from Ian acidified water solution (pH less than 7) with organic solvents such as chloroform. Similarly, basic drugs are readily removed from a basic water solution (pH greater than 7) with organicTsolvents. This simple approach gives the toxicologist a general technique for extracting and categorizing drugs. Some of the more commonly encountered drugs H may be classified as follows: , Acid Drugs Basic Drugs Barbiturates J Acetylsalicylic acid (aspirin) Phencyclidine Methadone Amphetamines Cocaine O S H SCREENING AND CONFIRMATION Once the specimen has been extracted and divided into acidic and basic fractions,Uthe toxicologist can identify the drugs present. The strategy for identifying abused drugs entails a two-step approach: screening and confirmation (see A Figure 12–7). A screening test is normally employed to give the analyst quick insight into the likelihood that a specimen contains a drug substance. This test allows a toxicologist to examine a large number of specimens within a short period of time for a wide range of drugs. 6 8 9 FIGURE 12–7 Biological fluids and tissues are 0 extracted for acidic and basic drugs by controlling the pH of a water solution in which they B are dissolved. Once this is accomplished, the toxicologist analyzes for U Sample Extraction at appropriate pH drugs by using screening and confirmation test procedures. Acidic Drugs Basic Drugs CONFIRMATION TEST Gas chromatography/mass spectrometry Criminalistics: An Introduction to Forensic Science, Eleventh Edition, by Richard Saferstein. Published by Prentice Hall. Copyright © 2015 by Pearson Education, Inc. ISBN: 978-1-323-16745-8 SCREENING TEST Immunoassay Gas chromatography Thin-layer chromatography FORENSIC TOXICOLOGY 317 Any positive results from a screening test are tentative at best and must be verified with a confirmation test. The three most widely used screening tests are thin-layer chromatography (TLC), gas chromatography (GC), and immunoassay. The techniques of GC and TLC have already been described on pages 279–282 and 284–285, respectively. An immunoassay has proven to be a useful screening tool in toxicology laboratories. Its principles are very different from any of the analytical techniques we have discussed so far. Basically, immunoassay is based on specific drug antibody reactions. We will learn about this concept in Chapter 14. The primary advantage of immunoassay is its ability to detect small concentrations of drugs in body fluids and organs. In fact, this technique provides the best approach for detecting the low drug levels normally associated with smoking marijuana. The necessity of eliminating the possibility that a positive screening test may be due to a substance’s having a close chemical structure to an abused drug requires the toxicologist to follow up a positive screening test with a confirmation test. Because of the potential impact of the results of a drug finding on an individual, only the most conclusive confirmation procedures should be used. Gas chromatography/mass spectrometry Sis generally accepted as the confirmation test of choice. The combination of gas chromatography and mass spectrometry M sensitivity and specificprovides the toxicologist with a one-step confirmation test of unequaled ity (see pages 291–292). As shown in Figure 12–8, the sample isI separated into its components by the gas chromatograph. When the separated sample component leaves the column of the gas chromatograph, it enters the mass spectrometer, where it isTbombarded with high-energy electrons. This bombardment causes the sample to break up into Hfragments, producing a fragmentation pattern or mass spectrum for each sample. For most compounds, the mass spectrum , represents a unique “fingerprint” pattern that can be used for identification. There is tremendous interest in drug-testing programs conducted not only in criminal matters but for industry and government as well. Urine testing for drugs is becoming common for J job applicants and employees in the workplace. Likewise, the U.S. military has an extensive drug urine-testing program for its members. Many urine-testing programs O rely on private laboratories to perform the analyses. In any case, when the test results form the basis for taking action against S an individual, both a screening and confirmation test must be incorporated into the testing protoH col to ensure the integrity of the laboratory’s conclusions. U When a forensic toxicological examination on a living person is required, practicality limits available specimens to blood and urine. Most drugs remain in the A bloodstream for about 24 hours; in urine, they normally are present up to 72 hours. However, it may be necessary to go further back in time to ascertain whether a subject has been abusing a drug. If so, the only viable alternative to blood and urine is head 6 hair. Hair is nourished by blood flowing through capillaries located close to the hair root. Drugs 8 of the hair and become perpresent in blood diffuse through the capillary walls into the base manently entrapped in the hair’s hardening protein structure. As9the hair continues to grow, the DETECTING DRUGS IN HAIR Gas chromatograph 0 B U C A B D Mass spectrometer A B C D ISBN: 978-1-323-16745-8 Chromatogram Spectra FIGURE 12–8 The combination of the gas chromatograph and the mass spectrometer enables forensic toxicologists to separate the components of a drug mixture and provides specific identification of a drug substance. Criminalistics: An Introduction to Forensic Science, Eleventh Edition, by Richard Saferstein. Published by Prentice Hall. Copyright © 2015 by Pearson Education, Inc. 318 CHAPTER 12 drug’s location on the hair shaft becomes a historical marker for delineating drug intake. Given that the average human head hair grows at the rate of 1 centimeter per month, analyzing segments of hair for drug content may define the timeline for drug use, dating it back over a period of weeks, months, or even years, depending on the hair’s length. However, caution is required in interpreting the timeline. The chronology of drug intake may be distorted by drugs penetrating the hair’s surface as a result of environmental exposure, or drugs may enter the hair’s surface through sweat. Nevertheless, drug hair analysis is the only viable approach for measuring long-term abuse of a drug. Detecting Nondrug Poisons Although forensic toxicologists devote most of their efforts to detecting drugs, they also test for a wide variety of other toxic substances. Some of these are rare elements, not widely or commercially available. Others are so common that virtually everyone is exposed to nontoxic amounts of them every day. HEAVY METALS The forensicStoxicologist only occasionally encounters a group of poisons known as heavy metals. TheseMinclude arsenic, bismuth, antimony, mercury, and thallium. To screen for many of these metals, the investigator may dissolve the suspect body fluid or I tissue in a hydrochloric acid solution and insert a copper strip into the solution (the Reinsch test). The appearance of a silvery or dark coating on the copper indicates the presence of a T heavy metal. Such a finding must be confirmed by the use of analytical techniques suitable for H absorption spectrophotometry, emission spectroscopy, or inorganic analysis—namely, atomic X-ray diffraction. , CARBON MONOXIDE Unlike heavy metals, carbon monoxide still represents one of the most common poisons encountered in a forensic laboratory. When carbon monoxide enters the human body, it is primarily absorbed J by the red blood cells, where it combines with hemoglobin to form carboxyhemoglobin. An O average red blood cell contains about 280 million molecules of hemoglobin. Oxygen normally combines with hemoglobin, which transports the oxygen throughout the body. However,Sif a high percentage of the hemoglobin combines with carbon monoxide, not enough is left toH carry sufficient oxygen to the tissues, and death by asphyxiation quickly follows. U There are two basic methods for measuring the concentration of carbon monoxide in the blood. Spectrophotometric methods A examine the visible spectrum of blood to determine the amount of carboxyhemoglobin relative to oxyhemoglobin or total hemoglobin; also, a volume of blood can be treated with a reagent to liberate the carbon monoxide, which is then measured by gas chromatography. 6 The amount of carbon monoxide in blood is generally expressed as percent saturation. This 8 represents the extent to which the available hemoglobin has been converted to carboxyhemoglobin. The transition from normal or9occupational levels of carbon monoxide to toxic levels is not sharply defined. It depends, among other things, on the age, health, and general fitness of each 0 individual. In a healthy middle-aged individual, a carbon monoxide blood saturation greater B fatal. However, in combination with alcohol or other depresthan 50–60 percent is considered sants, fatal levels may be significantly lower. For instance, a carbon monoxide saturation of U 35–40 percent may prove fatal in the presence of a blood-alcohol concentration of 0.20 percent w/v. Interestingly, chain smokers may have a constant carbon monoxide level of 8–10 percent from the carbon monoxide in cigarette smoke. Inhaling automobile fumes is a relatively common way to commit suicide. A garden or vacuum cleaner hose is often used to connect the tailpipe with the vehicle’s interior, or the engine is allowed to run in a closed garage. A level of carbon monoxide sufficient to cause death accumulates in five to ten minutes in a closed single-car garage. ISBN: 978-1-323-16745-8 Criminalistics: An Introduction to Forensic Science, Eleventh Edition, by Richard Saferstein. Published by Prentice Hall. Copyright © 2015 by Pearson Education, Inc. case files FORENSIC TOXICOLOGY Joann Curley: Caught by a Hair A vibrant young woman named Joann Curley rushed to the Wilkes-Barre (Pennsylvania) General Hospital—her husband, Bobby, was having an attack and required immediate medical attention. Bobby was experiencing a burning sensation in his feet, numbness in his hands, a flushed face, and intense sweating. He was diagnosed with Guillain-Barré syndrome, an acute inflammation of the nervous system that accounted for all of Bobby’s symptoms. After being discharged, Bobby experienced another bout of debilitating pain and numbness. He was admitted to another hospital, the larger and more capable Hershey Medical Center in Hershey, Pennsylvania. There docS tors observed extreme alopecia, or hair loss. Test results of Bobby’s urine showed high levels of the M heavy metal thallium in his body. Thallium, a rare and highly I toxic metal that was used decades ago in substances such as rat poison and to treat ringworm and gout, was found in suffiT cient quantities to cause Bobby’s sickness. The use of thallium was banned in the United States in 1984. Now, at least, Bobby H could be treated. However, before Bobby’s doctors could treat , him for thallium poisoning, he experienced cardiac arrest and slipped into a coma. Joann Curley made the difficult decision to remove her husband of 13 months from life support equipment. He died shortly thereafter. J Bobby Curley was an electrician and, for five months beO fore his death, he worked in the chemistry department at nearby Wilkes University. Authorities suspected that Bobby had been S accidentally exposed to thallium there among old chemicals H and laboratory equipment. The laboratory was searched and several old bottles of powdered thallium salts were discovU ered in a storage closet. After testing of the air and surfaces, these were eliminated as possible sources for exposure. This A 319 finding was supported by the discovery that none of Bobby’s co-workers had any thallium in their systems. The next most logical route of exposure was in the home; thus, the Curley kitchen was sampled. Of the hundreds of items tested, three thermoses were found to contain traces of thallium. Investigators also learned that Bobby had changed his life insurance to list his wife, Joann, as the beneficiary of his $300,000 policy. Based on this information, police consulted a forensic toxicologist in an effort to glean as much from the physical evidence in Bobby Curley’s body as possible. The toxicologist conducted segmental analysis of Bobby’s hair, an analytical method based on the predictable rate of hair growth on the human scalp: an average of 1 centimeter per month. Bobby had approximately 5 inches (12.5 centimeters) of hair, which represents almost twelve months of hair growth. Each section tested represented a specific period of time in Bobby’s final year of his life. The hair analysis proved that Bobby Curley was poisoned with thallium long before he began working at Wilkes University. The first few doses were small, which probably barely made him sick at the time. Gradually, over a year or more, Bobby was receiving more doses of thallium until he finally succumbed to a massive dose three or four days before his death. After careful scrutiny of the timeline, investigators concluded that only Joann Curley had access to Bobby during each of these intervals. She also had motive, in the amount of $300,000. Presented with the timeline and the solid toxicological evidence against her, Joann Curley pleaded guilty to murder. As part of her plea agreement, she provided a 40-page written confession of how she haphazardly dosed Bobby with some rat poison she found in her basement. She admitted that she murdered him for the money she would receive from Bobby’s life insurance policy. 6 The level of carbon monoxide in the blood of a victim found dead at the scene of a fire is 8 of carbon monoxide in the significant in ascertaining whether foul play has occurred. High levels blood prove that the victim breathed the combustion products of 9 the fire and was alive when the fire began. Many attempts at covering up a murder by setting fire to a victim’s house or car have 0 been uncovered in this manner. ISBN: 978-1-323-16745-8 Significance of Toxicological Findings B U Once a drug is found and identified, the toxicologist assesses its influence on the behavior of the individual. Interpreting the results of a toxicology find is one of the toxicologist’s more difficult chores. Recall that many of the world’s countries have designated a specific bloodalcohol level at which an individual is deemed under the influence of alcohol. These levels were established as a result of numerous studies conducted over several years to measure the effects of alcohol levels on driving performance. However, no such legal guidelines are available to the toxicologist who must judge how a drug other than alcohol affects an individual’s performance or physical state. Criminalistics: An Introduction to Forensic Science, Eleventh Edition, by Richard Saferstein. Published by Prentice Hall. Copyright © 2015 by Pearson Education, Inc. 320 CHAPTER 12 For many drugs, blood concentration levels are readily determined and can be used to estimate the pharmacological effects of the drug on the individual. Often, when dealing with a living person, the toxicologist has the added benefit of knowing what a police officer may have observed about an individual’s behavior and motor skills, as well as the outcome of a drug influence evaluation conducted by a police officer trained to be a drug recognition expert (discussed shortly). For a deceased person, drug levels in various body organs and tissues provide additional information about the individual’s state at the time of death. However, before conclusions can be drawn about a drug-induced death, other factors must also be considered, including the age, physical condition, and tolerance of the drug user. With prolonged use of a drug, an individual may become less responsive to a drug’s effects and tolerate blood-drug concentrations that would kill a casual drug user. Therefore, knowledge of an individual’s history of drug use is important in evaluating drug concentrations. Another consideration is additive or synergistic effects of the interaction of two or more drugs, which may produce a highly intoxicated or comatose state even though none of the drugs alone is present at high or toxic levels. The combination of alcohol with tranquilizers or narcotics is a common example of a potentially lethal drug S combination. The presence of a drug present in urine is a poor indicator of how extensively an individual’s Mthe drug. Urine is formed outside the body’s circulatory system, behavior or state is influenced by and consequently drug levels can I build up in it over a long period. Some drugs are found in the urine one to three days after they have been taken and long after their effects on the user have disappeared. Nevertheless, the T value of this information should not be discounted. Urine drug levels, like blood levels, are best Hused by law enforcement authorities and the courts to corroborate other investigative and medical findings regarding an individual’s condition. Hence, for an , individual who is arrested for suspicion of being under the influence of a drug, a toxicologist’s determinations supplement the observations of the arresting officer, including the results of a drug influence evaluation (discussed next). J For a deceased person, the responsibility for establishing a cause of death rests with the medical examiner or coroner. However, before a conclusive determination is made, the examinO ing physician depends on the forensic toxicologist to demonstrate the presence or absence of a S drug or poison in the tissues or body fluids of the deceased. Only through the combined efforts of the toxicologist and the medicalH examiner (or coroner) can society be assured that death investigations achieve high professional and legal standards. U A The Drug Recognition Expert 6 Whereas recognizing alcohol-impaired performance is an expertise generally accorded to police officers by the courts, recognizing drug-induced intoxication is much more difficult and gener8 ally not part of police training. During the 1970s, the Los Angeles Police Department developed 9psychophysical examinations that a trained police officer could and tested a series of clinical and use to identify and differentiate0between types of drug impairment. This program has evolved into a national program to train police as drug recognition experts. Normally, a three- to fiveB to certify an officer as a drug recognition expert (DRE). month training program is required The DRE program incorporates U standardized methods for examining suspects to determine whether they have taken one or more drugs. The process is systematic and standard; to ensure that each subject has been tested in a routine fashion, each DRE must complete a standard Drug Influence Evaluation form (see Figure 12–9). The entire drug evaluation takes approximately 30 to 40 minutes. The components of the 12-step process are summarized in Table 12–1. The DRE evaluation process can suggest the presence of the following seven broad categories of drugs: Central nervous system depressants Central nervous system stimulants Hallucinogens Dissociative anesthetics (includes phencyclidine and its analogs) Inhalants Narcotic analgesics Cannabis Criminalistics: An Introduction to Forensic Science, Eleventh Edition, by Richard Saferstein. Published by Prentice Hall. Copyright © 2015 by Pearson Education, Inc. ISBN: 978-1-323-16745-8 1. 2. 3. 4. 5. 6. 7. FORENSIC TOXICOLOGY 321 J O S H U A ISBN: 978-1-323-16745-8 FIGURE 12–9 Drug Influence Evaluation form. 6 8 9 0 B U National Highway Traffic Safety Administration S M I T H , The DRE program is not designed to be a substitute for toxicological testing. The toxicologist can often determine that a suspect has a particular drug in his or her body. But the toxicologist often cannot infer with reasonable certainty that the suspect was impaired at a specific time. On the other hand, the DRE can supply credible evidence that the suspect was impaired at a specific time and that the nature of the impairment was consistent with a particular family of drugs. But the DRE program usually cannot determine which specific drug was ingested. Proving drug intoxication requires a coordinated effort and the production of competent data from both the DRE and the forensic toxicologist. Criminalistics: An Introduction to Forensic Science, Eleventh Edition, by Richard Saferstein. Published by Prentice Hall. Copyright © 2015 by Pearson Education, Inc. 322 CHAPTER 12 TABLE 12–1 Components of the Drug Recognition Process 1. The Breath-Alcohol Test. By obtaining an accurate and immediate measurement of the suspect’s blood-alcohol concentration, the drug recognition expert (DRE) can determine whether alcohol may be contributing to the suspect’s observable impairment and whether the concentration of alcohol is sufficient to be the sole cause of that impairment. 2. Interview with the Arresting Officer. Spending a few minutes with the arresting officer often enables the DRE to determine the most promising areas of investigation. 3. The Preliminary Examination. This structured series of questions, specific observations, and simple tests provides the first opportunity to examine the suspect closely. It is designed to determine whether the suspect is suffering from an injury or from another condition unrelated to drug consumption. It also affords an opportunity to begin assessing the suspect’s appearance and behavior for signs of possible drug influence. S categories of drugs induce nystagmus, an involuntary, 4. The Eye Examination. Certain spasmodic motion of the eyeball. M Nystagmus is an indicator of drug-induced impairment. The inability of the eyes to converge toward the bridge of the nose also I of certain types of drugs. indicates the possible presence 5. Divided-Attention Psychophysical Tests. These tests check balance and physical T orientation and include the walk and turn, the one-leg stand, the Romberg balance, and H the finger-to-nose. 6. Vital Signs Examinations. Precise measurements of blood pressure, pulse rate, and body , temperature are taken. Certain drugs elevate these signs; others depress them. 7. Dark Room Examinations. The size of the suspect’s pupils in room light, near-total darkness, indirect light, and J direct light is checked. Some drugs cause the pupils to either dilate or constrict. O Certain categories of drugs cause the muscles to 8. Examination for Muscle Rigidity. become hypertense and quite S rigid. Others may cause the muscles to relax and become flaccid. H Users of certain categories of drugs routinely or 9. Examination for Injection Sites. occasionally inject their drugs. U Evidence of needle use may be found on veins along the neck, arms, and hands. 10. Suspect’s Statements and A Other Observations. The next step is to attempt to interview the suspect concerning the drug or drugs he or she has ingested. Of course, the interview must be conducted in full compliance with the suspect’s constitutional rights. 6 11. Opinions of the Evaluator. Using the information obtained in the previous ten steps, the DRE can make an informed 8 decision about whether the suspect is impaired by drugs and, if so, what category or combination of categories is the probable cause of the 9 impairment. 12. The Toxicological Examination. 0 The DRE should obtain a blood or urine sample from the suspect for laboratory analysis in order to secure scientific, admissible evidence to B substantiate his or her conclusions. U ISBN: 978-1-323-16745-8 Criminalistics: An Introduction to Forensic Science, Eleventh Edition, by Richard Saferstein. Published by Prentice Hall. Copyright © 2015 by Pearson Education, Inc. chapter summary Toxicologists detect and identify the presence of drugs and poisons in body fluids, tissues, and organs. A major branch of forensic toxicology deals with the measurement of alcohol in the body for matters that pertain to violations of criminal law. Alcohol appears in the blood within minutes after it has been taken by mouth and slowly increases in concentration while it is being absorbed from the stomach and the small intestine into the bloodstream. When all the alcohol has been absorbed, a maximum alcohol level is reached in the blood and the postabsorption period begins. Then the alcohol concentration slowly decreases until a zero level is again reached. Alcohol is eliminated from the body through oxidation and excretion. Oxidation takes place almost entirely in the liver, whereas alcohol is excreted unchanged in the breath, urine, and perspiration. The extent to which an individual is under the influence of alcohol is usually determined by measuring the quantity of alcohol in the blood or the breath. Breath testers that operate on the principle of infrared light absorption are becoming increasingly popular within the law enforcement community. Many types of breath testers analyze a set volume of breath. The sampled breath is exposed to infrared light. The degree of interaction of the light with alcohol in the breath sample allows the instrument to measure a blood-alcohol concentration in breath. These breath-testing devices operate on the principle that the ratio between the concentration of alcohol in deep-lung or alveolar breath and its concentration in blood is fixed. Most breath-test devices have set the ratio of alcohol in the blood to alcohol in alveolar air at 2,100 to 1. Law enforcement officers typically use field sobriety tests to estimate a motorist’s degree of physical impairment by alcohol and whether an evidential test for alcohol is justified. The horizontal-gaze nystagmus test, walk and turn, and ISBN: 978-1-323-16745-8 review questions 1. The most heavily abused drug in the Western world is ___________. 2. True or False: Toxicologists are employed only by crime laboratories. ___________ 3. The amount of alcohol in the blood (is, is not) directly proportional to the concentration of alcohol in the brain. 4. True or False: Blood levels have become the accepted standard for relating alcohol intake to its effect on the body. ___________ 5. Alcohol consumed on an empty stomach is absorbed (faster, slower) than an equivalent amount of alcohol taken when there is food in the stomach. 6. Under normal drinking conditions, alcohol concentration in the blood peaks in ___________ to ___________ minutes. the one-leg stand are all reliable and effective psychophysical tests. Gas chromatography is the most widely used approach for determining alcohol levels in blood. Blood must always be drawn under medically accepted conditions by a qualified individual. A nonalcoholic disinfectant must be applied before the suspect’s skin is penetrated with a sterile needle or lancet. Once blood is removed from an individual, it is best preserved sealed in an airtight container after adding an anticoagulant and a preservative. The forensic toxicologist must devise an analytical scheme to detect, isolate, and identify toxic drug substances. S Once the drug has been extracted from appropriate biological Mfluids, tissues, and organs, the forensic toxicologist can idenI tify the drug substance. The strategy for identifying abused entails a two-step approach: screening and confirmaTdrugs tion. A screening test gives the analyst quick insight into the Hlikelihood that a specimen contains a drug substance. Positive from a screening test are tentative at best and must be , results verified with a confirmation test. The most widely used screening tests are thin-layer chromatography, gas chromatography, immunoassay. Gas chromatography/mass spectrometry is Jand generally accepted as the confirmation test of choice. Once Othe drug is extracted and identified, the toxicologist may be to judge the drug’s effect on an individual’s natural Srequired performance or physical state. The Drug Recognition Expert Hprogram incorporates standardized methods for examining Uautomobile drivers suspected of being under the influence of drugs. But the DRE program usually cannot determine which Aspecific drug was ingested. Hence, reliable data from both the DRE and the forensic toxicologist are required to prove drug intoxication. 6 8 9 0 B7. U In the postabsorption period, alcohol is distributed uniformly among the ___________ portions of the body. 8. Alcohol is eliminated from the body by ___________ and ___________. 9. Ninety-five to 98 percent of the alcohol consumed is ___________ to carbon dioxide and water. 10. Oxidation of alcohol takes place almost entirely in the ___________. 11. The amount of alcohol exhaled in the ___________ is directly proportional to the concentration of alcohol in the blood. 12. Alcohol is eliminated from the blood at an average rate of ___________ percent w/v. Criminalistics: An Introduction to Forensic Science, Eleventh Edition, by Richard Saferstein. Published by Prentice Hall. Copyright © 2015 by Pearson Education, Inc. 324 CHAPTER 12 living person suspected of being under the influence of a drug. 26. A large number of drugs can be classified chemically as ___________ and ___________. 27. Water with a pH value (less, greater) than 7 is basic. 13. Alcohol is absorbed into the blood from the ___________ and ___________. 14. Most modern breath testers use ___________ radiation to detect and measure alcohol in the breath. 15. To avoid the possibility of “mouth alcohol,” the operator of a breath tester must not allow the subject to take any foreign materials into the mouth for ___________ minutes before the test. 28. Barbiturates are classified as ___________ drugs. 29. Drugs are extracted from body fluids and tissues by carefully controlling the ___________ of the medium in which the sample has been dissolved. 16. Alcohol can be separated from other volatiles in blood and quantitated by the technique of ___________. 30. The technique of ___________ is based on specific drug antibody reactions. 17. Roadside breath testers that use a(n) ___________ detector are becoming increasingly popular with the law enforcement community. 18. True or False: Portable handheld roadside breath testers for alcohol provide evidential test results. ___________ 19. Usually, when a person’s blood-alcohol concentration is in the range of 0.10 percent, horizontal-gaze nystagmus begins before the eyeball has moved ___________ degrees to the side. 20. When drawing blood for alcohol testing, the suspect’s skin must first be wiped with a(n) ___________ disinfectant. 21. Failure to add a preservative, such as sodium fluoride, to blood removed from a living person may lead to a(n) (decline, increase) in alcohol concentration. 22. Most states have established ___________ percent w/v as the impairment limit for blood-alcohol concentration. 23. In the case of ___________, the Supreme Court ruled that taking nontestimonial evidence, such as a blood sample, did not violate a suspect’s Fifth Amendment rights. 24. Heroin is changed upon entering the body into ___________. 25. The body fluids ___________ and ___________ are both desirable for the toxicological examination of a 31. Both ___________ and ___________ tests must be incorporated into the drug-testing protocol of a toxicology laboratory to ensure the correctness of the laboratory’s conclusions. S M 32. I T 33. H , 34. J 35. O 36. S H U 37. A 6 8 9 0 B U The gas ___________ combines with hemoglobin in the blood to form carboxyhemoglobin, thus interfering with the transportation of oxygen in the blood. The amount of carbon monoxide in blood is usually expressed as ___________. True or False: Blood levels of drugs can alone be used to draw definitive conclusions about the effects of a drug on an individual. ___________ Interaction of alcohol and barbiturates in the body can produce a(n) ___________ effect. The level of a drug present in the urine is by itself a (good, poor) indicator of how extensively an individual is affected by a drug. Urine and blood drug levels are best used by law enforcement authorities and the courts to ___________ other investigative and medical findings pertaining to an individual’s condition. 38. The ___________ program incorporates standardized methods for examining suspects to determine whether they have taken one or more drugs. review questions for inside the science 4. One milliliter of blood contains the same amount of alcohol as approximately ___________ milliliters of alveolar breath. 5. When alcohol is being absorbed into the blood, the alcohol concentration in venous blood is (higher, lower) than that in arterial blood. Criminalistics: An Introduction to Forensic Science, Eleventh Edition, by Richard Saferstein. Published by Prentice Hall. Copyright © 2015 by Pearson Education, Inc. ISBN: 978-1-323-16745-8 1. A(n) ___________ carries blood away from the heart; a(n) ___________ carries blood back to the heart. 2. The ___________ artery carries deoxygenated blood from the heart to the lungs. 3. Alcohol passes from the blood capillaries into the ___________ sacs in the lungs. FORENSIC TOXICOLOGY 325 application and critical thinking 1. Answer the following questions about driving risk associated with drinking and blood-alcohol concentration: a. Randy is just barely legally intoxicated. How much more likely is he to have an accident than someone who is sober? b. Marissa, who has been drinking, is 15 times as likely to have an accident as her sober friend, Christine. What is Marissa’s approximate blood-alcohol concentration? c. After several drinks, Charles is ten times as likely to have an accident as a sober person. Is he more or less intoxicated than James, whose blood-alcohol level is 0.10? d. Under the original blood-alcohol standards recommended by NHTSA, a person considered just barely legally intoxicated was how much more likely to have an accident than a sober individual? 2. Following is a description of four individuals who have been drinking. Rank them from highest to lowest bloodalcohol concentration: a. John, who weighs 200 pounds and has consumed eight 8-ounce drinks on a full stomach b. Frank, who weighs 170 pounds and has consumed four 8-ounce drinks on an empty stomach c. Gary, who weighs 240 pounds and has consumed six 8-ounce drinks on an empty stomach d. Stephen, who weighs 180 pounds and has consumed six 8-ounce drinks on a full stomach ISBN: 978-1-323-16745-8 further references Benjamin, David M., “Forensic Pharmacology,” in R. Saferstein, ed., Forensic Science Handbook, vol. 3, 2nd ed. Upper Saddle River, N.J.: Prentice Hall, 2010. Caplan, Y. H., and J. R. Zettl, “The Determination of Alcohol in Blood and Breath,” in R. Saferstein, ed., Forensic Science Handbook, vol. 1, 2nd ed. Upper Saddle River, N.J.: Prentice Hall, 2002. Couper, F. J., and B. K. Logan, Drugs and Human Performance. Washington, D.C.: National Highway Traffic Safety Administration, 2004, http://www.nhtsa .dot.gov/people/injury/research/job185drugs/ technical-page.htm 3. Following is a description of four individuals who have been drinking. In which (if any) of the following countries would each be considered legally drunk: the United States, Australia, Sweden? a. Bill, who weighs 150 pounds and has consumed three 8-ounce drinks on an empty stomach b. Sally, who weighs 110 pounds and has consumed three 8-ounce drinks on a full stomach c. Rich, who weighs 200 pounds and has consumed six 8-ounce drinks on an empty stomach S M4. I T H , d. Carrie, who weighs 140 pounds and has consumed four 8-ounce drinks on a full stomach You are a forensic scientist who has been asked to test two blood samples. You know that one sample is suspected of containing barbiturates and the other contains no drugs; however, you cannot tell the two samples apart. Describe how you would use the concept of pH to determine which sample contains barbiturates. Explain your reasoning. 5. You are investigating an arson scene and you find a in the rubble, but you suspect that the victim did J corpse not die as a result of the fire. Instead, you suspect that O the victim was murdered earlier, and that the blaze was to cover up the murder. How would you go about S started determining whether the victim died before the fire? H U A 6 8 9 0Garriott, James C., ed., Medicolegal Aspects of Alcohol, B 5th ed. Tucson, Ariz.: Lawyers & Judges, 2009. Levine, B., ed., Principles of Forensic Toxicology, 3rd ed. U Washington, D.C.: AACC Press, 2006. Ropero-Miller, J. D., and B. A. Goldberger, eds., Handbook of Workplace Drug Testing, 2nd ed. Washington, D.C.: AACC Press, 2009. Criminalistics: An Introduction to Forensic Science, Eleventh Edition, by Richard Saferstein. Published by Prentice Hall. Copyright © 2015 by Pearson Education, Inc. headline news The Green River Killer ©Z , In Press UMA c./Ala my This case takes its name from the Green River, which flows through Washington state and empties into Puget Sound in Seattle. In 1982, within six months the bodies of five females were discovered in or near the river. Most of the victims were known prostitutes who were strangled and apparently S raped. As police focused their attention on an area known M Strip, a haven for prostitutes, girls mysteriously as Sea-Tac I disappeared with increasing frequency. By the end of 1986,Tthe body count in the Seattle region rose to 40, all H of whom were believed to have been murdered by the , Green River Killer. As the investigation pressed on into 1987, the police renewed their interest in one suspect, Gary Ridgway, a local truck painter. J Interestingly, in 1984 Ridgway had passed a lie O detector test. Now with a search warrant in hand, Spolice searched the Ridgway residence and also Hobtained hair and saliva samples from Ridgway. U Again, insufficient evidence caused Ridgway A to be released from custody. However, as the investigation proceeded, a DNA link between 6 Ridgway and his victims eluded investigators. 8 Ultimately, a careful microscopic search of Ridgway’s clothing revealed the presence of paint spheres 9 of various colors, which compared to spheres on the clothing of six 0 of the victims. The paint was microscopically and chemically identified as Imron, a B high-end specialty paint that was manufactured before 1984. This product had been used at U as dried paint spheres emanating from a spray the truck plant where Ridgway worked and was identified paint. Two of the victims were further linked to Ridgway through DNA, further solidifying the case against Ridgway. Ridgway avoided the death penalty by confessing to the murders of 48 women. ISBN: 978-1-323-16745-8 Criminalistics: An Introduction to Forensic Science, Eleventh Edition, by Richard Saferstein. Published by Prentice Hall. Copyright © 2015 by Pearson Education, Inc. chapter 13 metals, paint, and soil Learning Objectives S M I T H , J After studying this chapter you should be able to: t
Describe the usefulness of trace elements O for forensic comp...
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