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10- PRENTICE HALL ©2007 Pearson Education, Inc. Upper Saddle River, NJ 07458 CRIMINALISTICS An Introduction to Forensic Science, 9/E By Richard Saferstein.

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Presentation on theme: "10- PRENTICE HALL ©2007 Pearson Education, Inc. Upper Saddle River, NJ 07458 CRIMINALISTICS An Introduction to Forensic Science, 9/E By Richard Saferstein."— Presentation transcript:

1 10- PRENTICE HALL ©2007 Pearson Education, Inc. Upper Saddle River, NJ 07458 CRIMINALISTICS An Introduction to Forensic Science, 9/E By Richard Saferstein 1 Chapter 9 Forensic Toxicology

2 10- PRENTICE HALL ©2007 Pearson Education, Inc. Upper Saddle River, NJ 07458 CRIMINALISTICS An Introduction to Forensic Science, 9/E By Richard Saferstein 2 Introduction: Toxicologists Detect and identify –presence of drugs and poisons –body fluids –Tissues –organs Work in crime laboratories and medical examiners’ offices May also reach into hospital laboratories and health facilities to identify a drug overdose or monitor the intake of drugs Major branch: measurement of alcohol in the body (violations of criminal law)

3 10- PRENTICE HALL ©2007 Pearson Education, Inc. Upper Saddle River, NJ 07458 CRIMINALISTICS An Introduction to Forensic Science, 9/E By Richard Saferstein 3 Toxicology of Alcohol

4 10- PRENTICE HALL ©2007 Pearson Education, Inc. Upper Saddle River, NJ 07458 CRIMINALISTICS An Introduction to Forensic Science, 9/E By Richard Saferstein 4 Toxicology of Alcohol Analysis of alcohol example –Primary objective of forensic toxicology –Detection and isolation of drugs in the body –Purpose of determining influence on human behavior Alcohol (ethanol, ethyl alcohol) –Colorless liquid –Normally diluted with water –Consumed as a beverage CNS depressant

5 10- PRENTICE HALL ©2007 Pearson Education, Inc. Upper Saddle River, NJ 07458 CRIMINALISTICS An Introduction to Forensic Science, 9/E By Richard Saferstein 5 Alcohol Levels Alcohol appears in the blood within minutes –Slowly increases in concentration while it is being absorbed from the stomach (20%) and the small intestine –All the alcohol absorbed  maximum alcohol level reached in the blood Post absorption period begins –Concentration slowly decreases until a zero level is again reached Factors influencing rate of absorption –Time taken to consume the drink –Alcohol content –Amount consumed –Food present in the stomach.

6 10- PRENTICE HALL ©2007 Pearson Education, Inc. Upper Saddle River, NJ 07458 CRIMINALISTICS An Introduction to Forensic Science, 9/E By Richard Saferstein 6 Alcohol Levels Elimination of alcohol throughout the body –Oxidation: in the liver –Excretion: unchanged in breath, urine, perspiration Measure –Blood alcohol –Alcohol content in the breath: direct proportion to the blood concentration

7 10- PRENTICE HALL ©2007 Pearson Education, Inc. Upper Saddle River, NJ 07458 CRIMINALISTICS An Introduction to Forensic Science, 9/E By Richard Saferstein 7 Alcohol and Circulatory System Closed circulatory system consisting of a heart, arteries, veins, and capillaries Alcohol absorbed from the stomach and small intestines Carried to the liver where the process of its destruction starts Blood, carrying alcohol, moves to the heart, pumped to the lungs –Carbon dioxide and alcohol leave the blood –Oxygen enters the blood in the air sacs (alveoli) Carbon dioxide, alcohol exhaled

8 10- PRENTICE HALL ©2007 Pearson Education, Inc. Upper Saddle River, NJ 07458 CRIMINALISTICS An Introduction to Forensic Science, 9/E By Richard Saferstein 8 Figure 10–2 Dark vessels contain oxygenated blood; light vessels contain deoxygenated blood. Human Circulatory System

9 10- PRENTICE HALL ©2007 Pearson Education, Inc. Upper Saddle River, NJ 07458 CRIMINALISTICS An Introduction to Forensic Science, 9/E By Richard Saferstein 9 Figure 10–3b 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. The Respiratory System

10 10- PRENTICE HALL ©2007 Pearson Education, Inc. Upper Saddle River, NJ 07458 CRIMINALISTICS An Introduction to Forensic Science, 9/E By Richard Saferstein 10 Figure 10–3a 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. Gas Exchange In The Lungs

11 10- PRENTICE HALL ©2007 Pearson Education, Inc. Upper Saddle River, NJ 07458 CRIMINALISTICS An Introduction to Forensic Science, 9/E By Richard Saferstein 11 Circulation YouTube - Circulation animation YouTube - St. Joseph Aspirin : Pumps Your Blood - Banjo ManYouTube - St. Joseph Aspirin : Pumps Your Blood - Banjo Man YouTube - Pumps Your Blood

12 10- PRENTICE HALL ©2007 Pearson Education, Inc. Upper Saddle River, NJ 07458 CRIMINALISTICS An Introduction to Forensic Science, 9/E By Richard Saferstein 12 Figure 10–10 Diagram of increased driving risk in relation to blood-alcohol concentration. Courtesy U.S. Department of Transportation, Washington, D.C. Driving Risk

13 10- PRENTICE HALL ©2007 Pearson Education, Inc. Upper Saddle River, NJ 07458 CRIMINALISTICS An Introduction to Forensic Science, 9/E By Richard Saferstein 13 Breath Test Instruments

14 10- PRENTICE HALL ©2007 Pearson Education, Inc. Upper Saddle River, NJ 07458 CRIMINALISTICS An Introduction to Forensic Science, 9/E By Richard Saferstein 14 Breath Testers Operate on the principle of infrared light absorption Becoming increasingly popular within the law enforcement community Designed to capture a set volume of breath Captured breath is exposed to infrared light

15 10- PRENTICE HALL ©2007 Pearson Education, Inc. Upper Saddle River, NJ 07458 CRIMINALISTICS An Introduction to Forensic Science, 9/E By Richard Saferstein 15 Breathalyzer Glass ampoule –Potassium dichromate –Sulfuric acid –Water –Silver nitrate catalyst Alcohol oxidized to acetic acid Potassium dichromate destroyed

16 10- PRENTICE HALL ©2007 Pearson Education, Inc. Upper Saddle River, NJ 07458 CRIMINALISTICS An Introduction to Forensic Science, 9/E By Richard Saferstein 16 Figure 10–4 Schematic diagram of a Breathalyzer. Courtesy Draeger Safety, Inc., Breathalyzer Division, Durango, Colo.

17 10- PRENTICE HALL ©2007 Pearson Education, Inc. Upper Saddle River, NJ 07458 CRIMINALISTICS An Introduction to Forensic Science, 9/E By Richard Saferstein 17 Infrared Breath-testing Instrument Breathalyzer phased out in 1970’s Replaced by computerized instruments Free of chemicals IR radiation absorption

18 10- PRENTICE HALL ©2007 Pearson Education, Inc. Upper Saddle River, NJ 07458 CRIMINALISTICS An Introduction to Forensic Science, 9/E By Richard Saferstein 18 Infrared Breath-testing Instrument Degree of the interaction of the light with alcohol in the captured breath sample that allows instrument to measure blood alcohol concentration in breath

19 10- PRENTICE HALL ©2007 Pearson Education, Inc. Upper Saddle River, NJ 07458 CRIMINALISTICS An Introduction to Forensic Science, 9/E By Richard Saferstein 19 Considerations in Breath Testing

20 10- PRENTICE HALL ©2007 Pearson Education, Inc. Upper Saddle River, NJ 07458 CRIMINALISTICS An Introduction to Forensic Science, 9/E By Richard Saferstein 20 Considerations in Breath Testing Instruments can be connected to external standard Sampled before an after subject test Unit must measure alveolar breath (deep lung breath) –1,5 liters breath needed

21 10- PRENTICE HALL ©2007 Pearson Education, Inc. Upper Saddle River, NJ 07458 CRIMINALISTICS An Introduction to Forensic Science, 9/E By Richard Saferstein 21 Considerations in Breath Testing Avoid measuring mouth alcohol –Regurgitation –Belching –Recent intake of alcohol –Alcohol mouthwash No foreign material 15-20 minutes before test Duplicate measurements within a few minutes

22 10- PRENTICE HALL ©2007 Pearson Education, Inc. Upper Saddle River, NJ 07458 CRIMINALISTICS An Introduction to Forensic Science, 9/E By Richard Saferstein 22 Field Sobriety Testing

23 10- PRENTICE HALL ©2007 Pearson Education, Inc. Upper Saddle River, NJ 07458 CRIMINALISTICS An Introduction to Forensic Science, 9/E By Richard Saferstein 23 Field Sobriety Testing Estimate motorist’s degree of physical impairment by alcohol Evidential test for alcohol justified? Preliminary breath-alcohol content –Portable, handheld, roadside breath tester –Contains fuel cell the oxidizes alcohol –Produces electrical current proportional to alcohol content

24 10- PRENTICE HALL ©2007 Pearson Education, Inc. Upper Saddle River, NJ 07458 CRIMINALISTICS An Introduction to Forensic Science, 9/E By Richard Saferstein 24 Field Sobriety Testing: Nystagmus Test Horizontal gaze n ystagmus test Involuntary jerking as eye moves to side Subject unaware of jerking 0.10 % blood alcohol  jerking before movement of 45 degrees

25 10- PRENTICE HALL ©2007 Pearson Education, Inc. Upper Saddle River, NJ 07458 CRIMINALISTICS An Introduction to Forensic Science, 9/E By Richard Saferstein 25 Field Sobriety Testing: Divided Attention Tests Comprehension of two instructions Walk and turn –Stand heel to toe –Walk nine steps heel-toe –Turn around –Repeat One-leg stand –Balance standing with heels together –Stand on one leg 30 seconds –Count aloud while standing

26 10- PRENTICE HALL ©2007 Pearson Education, Inc. Upper Saddle River, NJ 07458 CRIMINALISTICS An Introduction to Forensic Science, 9/E By Richard Saferstein 26 Analysis for Blood Alcohol

27 10- PRENTICE HALL ©2007 Pearson Education, Inc. Upper Saddle River, NJ 07458 CRIMINALISTICS An Introduction to Forensic Science, 9/E By Richard Saferstein 27 Gas Chromatography Testing Most widely used approach for determining alcohol levels in blood Blood must be –Drawn under medically accepted conditions –By a qualified individual Nonalcoholic disinfectant be applied before the suspect’s skin penetrated with a sterile needle or lancet Preservation –Anticoagulant and a preservative added –Sealed in an airtight container and stored in a refrigerator

28 10- PRENTICE HALL ©2007 Pearson Education, Inc. Upper Saddle River, NJ 07458 CRIMINALISTICS An Introduction to Forensic Science, 9/E By Richard Saferstein 28 Alcohol Dehydrogenase Used inclinical labs Enzyme plus NAD NADH formed – measured spectrophotometrically

29 10- PRENTICE HALL ©2007 Pearson Education, Inc. Upper Saddle River, NJ 07458 CRIMINALISTICS An Introduction to Forensic Science, 9/E By Richard Saferstein 29 Alcohol and Law

30 10- PRENTICE HALL ©2007 Pearson Education, Inc. Upper Saddle River, NJ 07458 CRIMINALISTICS An Introduction to Forensic Science, 9/E By Richard Saferstein 30 Figure 10–11 To use this diagram, lay a straightedge across your weight and the number of ounces of liquor you’ve consumed on an empty or full stomach. The point where the edge hits the right-hand column is your maximum blood-alcohol level.

31 10- PRENTICE HALL ©2007 Pearson Education, Inc. Upper Saddle River, NJ 07458 CRIMINALISTICS An Introduction to Forensic Science, 9/E By Richard Saferstein 31 Figure 10–11 The rate of elimination of alcohol from the bloodstream is approximately 0.015 percent per hour. Therefore, to calculate your actual blood-alcohol level, subtract 0.015 from the number in the right- hand column for each hour from the start of drinking.

32 10- PRENTICE HALL ©2007 Pearson Education, Inc. Upper Saddle River, NJ 07458 CRIMINALISTICS An Introduction to Forensic Science, 9/E By Richard Saferstein 32 Alcohol and Law Uniform and reasonable blood-alcohol standards –American medical association –National safety council Between 1939 and 1964 –Blood-alcohol level in excess of 0.15 percent w/v By 1965 was lowered to 0.10 percent In 1972 lowered again to 0.08 percent w/v

33 10- PRENTICE HALL ©2007 Pearson Education, Inc. Upper Saddle River, NJ 07458 CRIMINALISTICS An Introduction to Forensic Science, 9/E By Richard Saferstein 33 Alcohol and Law Starting in 2003 –States that have not adopted the 0.08 percent per se level –Lose part of their federal funds for highway construction National highway traffic safety administration recommended an “implied consent” law –Adopted by all states by 1973 –States that the operation of a motor vehicle on a public highway –Automatically carries stipulation that a driver will submit for a test for alcohol intoxication – Or subject to loose of the license

34 10- PRENTICE HALL ©2007 Pearson Education, Inc. Upper Saddle River, NJ 07458 CRIMINALISTICS An Introduction to Forensic Science, 9/E By Richard Saferstein 34 Schmerber v. California Blood drawn when Schmerber treated for accident injuries Supreme court: –Emergency situation –No time to obtain warrant –Drawn under medicallly accepted procedures Must be considered case-by-case

35 10- PRENTICE HALL ©2007 Pearson Education, Inc. Upper Saddle River, NJ 07458 CRIMINALISTICS An Introduction to Forensic Science, 9/E By Richard Saferstein 35 Role of the Toxicologist

36 10- PRENTICE HALL ©2007 Pearson Education, Inc. Upper Saddle River, NJ 07458 CRIMINALISTICS An Introduction to Forensic Science, 9/E By Richard Saferstein 36 Role of the Toxicologist Drugs and poisons Body fluids and/or organs Requested to examine them for the presence of drugs and poisons Toxicologist is forced to use general screening procedures Without supportive evidence –Victim’s symptoms –Postmortem pathological examination, –Examination of the victim’s personal effects

37 10- PRENTICE HALL ©2007 Pearson Education, Inc. Upper Saddle River, NJ 07458 CRIMINALISTICS An Introduction to Forensic Science, 9/E By Richard Saferstein 37 Role of the Toxicologist Not dealing with drugs at concentration levels found in powders and pills Dissipated and distributed throughout the body Body is an active chemistry laboratory –Substances enter and completely leave the body in the same chemical state Must be prepared to assess the toxicity of the drug or poison

38 10- PRENTICE HALL ©2007 Pearson Education, Inc. Upper Saddle River, NJ 07458 CRIMINALISTICS An Introduction to Forensic Science, 9/E By Richard Saferstein 38 Role of the Toxicologist Living person Blood –Tox screen 10 ml minimum –Alcohol 5 ml –More blood needed for alcohol-drug interaction Urine Taken in duplicate in separate containers cases

39 10- PRENTICE HALL ©2007 Pearson Education, Inc. Upper Saddle River, NJ 07458 CRIMINALISTICS An Introduction to Forensic Science, 9/E By Richard Saferstein 39 The Analytical Scheme

40 10- PRENTICE HALL ©2007 Pearson Education, Inc. Upper Saddle River, NJ 07458 CRIMINALISTICS An Introduction to Forensic Science, 9/E By Richard Saferstein 40 The Analytical Scheme Confirmation Tests Screening Tests

41 10- PRENTICE HALL ©2007 Pearson Education, Inc. Upper Saddle River, NJ 07458 CRIMINALISTICS An Introduction to Forensic Science, 9/E By Richard Saferstein 41 The Analytical Scheme Detect, isolate, and specifically identify toxic drug substances 90% of drugs –Alcohol –Cocaine

42 10- PRENTICE HALL ©2007 Pearson Education, Inc. Upper Saddle River, NJ 07458 CRIMINALISTICS An Introduction to Forensic Science, 9/E By Richard Saferstein 42 The Analytical Scheme Extract from appropriate biological fluids, tissues, and organs Based on a large number of drugs either acidic or basic

43 10- PRENTICE HALL ©2007 Pearson Education, Inc. Upper Saddle River, NJ 07458 CRIMINALISTICS An Introduction to Forensic Science, 9/E By Richard Saferstein 43 pH Definition of pH Acids: H donors Bases: H acceptors Minus log of H ion concentration

44 10- PRENTICE HALL ©2007 Pearson Education, Inc. Upper Saddle River, NJ 07458 CRIMINALISTICS An Introduction to Forensic Science, 9/E By Richard Saferstein 44 pH Scale

45 10- PRENTICE HALL ©2007 Pearson Education, Inc. Upper Saddle River, NJ 07458 CRIMINALISTICS An Introduction to Forensic Science, 9/E By Richard Saferstein 45 Categories by pH Acid DrugsBasic Drugs BarbituatesPhencyclidine Acetylsalicylic AcidMethadone Amphetamines Cocaine

46 10- PRENTICE HALL ©2007 Pearson Education, Inc. Upper Saddle River, NJ 07458 CRIMINALISTICS An Introduction to Forensic Science, 9/E By Richard Saferstein 46 The Analytical Scheme Identify the drug substance present –Screening –Confirmation

47 10- PRENTICE HALL ©2007 Pearson Education, Inc. Upper Saddle River, NJ 07458 CRIMINALISTICS An Introduction to Forensic Science, 9/E By Richard Saferstein 47 Techniques Used in Toxicology

48 10- PRENTICE HALL ©2007 Pearson Education, Inc. Upper Saddle River, NJ 07458 CRIMINALISTICS An Introduction to Forensic Science, 9/E By Richard Saferstein 48 The Screening Step Quick insight into likelihood that specimen contains a drug substance Positive results arising from screening test –Tentative at best –Must be verified with a confirmation test Most widely used screening tests –Thin-layer chromatography –Gas chromatography –Immunoassay

49 10- PRENTICE HALL ©2007 Pearson Education, Inc. Upper Saddle River, NJ 07458 CRIMINALISTICS An Introduction to Forensic Science, 9/E By Richard Saferstein 49 The Confirmation Step: GC-MS Confirmation test of choice. Gc separates the sample into components MS represents a unique “fingerprint” pattern that can be used for identification May be required to provide an opinion on the drug’s effect on an individual’s natural performance or physical state

50 10- PRENTICE HALL ©2007 Pearson Education, Inc. Upper Saddle River, NJ 07458 CRIMINALISTICS An Introduction to Forensic Science, 9/E By Richard Saferstein 50 Figure 10–13 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.

51 10- PRENTICE HALL ©2007 Pearson Education, Inc. Upper Saddle River, NJ 07458 CRIMINALISTICS An Introduction to Forensic Science, 9/E By Richard Saferstein 51 Heavy Metals Metals included –Arsenic –Bismuth –Antimony –Mercury –Thallium Reinsch test –Dissolve in HCl –Copper strip –Silvery or dark coating

52 10- PRENTICE HALL ©2007 Pearson Education, Inc. Upper Saddle River, NJ 07458 CRIMINALISTICS An Introduction to Forensic Science, 9/E By Richard Saferstein 52 Carbon Monoxide Combines with hemoglobin Interferes with oxygen carrying capacity of blood Methods –Spectrophotometric spectrum: carboxyhemoglobin –Liberate CO: measure by GC

53 10- PRENTICE HALL ©2007 Pearson Education, Inc. Upper Saddle River, NJ 07458 CRIMINALISTICS An Introduction to Forensic Science, 9/E By Richard Saferstein 53 Carbon Monoxide Expressed as % saturation Middle aged person: greater than 50- 60% sat. fatal With alcohol (0.20%): 35-40% sat. fatal Chain smokers: 8-10% sat. Suicide 5-10 minutes in garage Fire victim: low CO  murder

54 10- PRENTICE HALL ©2007 Pearson Education, Inc. Upper Saddle River, NJ 07458 CRIMINALISTICS An Introduction to Forensic Science, 9/E By Richard Saferstein 54 Significance of Toxicological Findings

55 10- PRENTICE HALL ©2007 Pearson Education, Inc. Upper Saddle River, NJ 07458 CRIMINALISTICS An Introduction to Forensic Science, 9/E By Richard Saferstein 55 Significance of Toxicological Findings Used to assess influence on behavior Alcohol levels proscribed by law Other drugs –Only estimate of effects Live person –Police report of behavior (DRE) Deceased person –Levels in various organs –Info on use history –Synergy between drugs

56 10- PRENTICE HALL ©2007 Pearson Education, Inc. Upper Saddle River, NJ 07458 CRIMINALISTICS An Introduction to Forensic Science, 9/E By Richard Saferstein 56 Drug Recognition Expert (DRE)

57 10- PRENTICE HALL ©2007 Pearson Education, Inc. Upper Saddle River, NJ 07458 CRIMINALISTICS An Introduction to Forensic Science, 9/E By Richard Saferstein 57 Drug Recognition Expert (DRE) Standardized methods for examining automobile drivers suspected of being under influence of drugs Ensure that each subject tested in a routine fashion DRE must complete a standard drug influence evaluation form Usually cannot determine which specific drug was ingested Reliable data from both the DRE and forensic toxicologist required to prove drug intoxication

58 10- PRENTICE HALL ©2007 Pearson Education, Inc. Upper Saddle River, NJ 07458 CRIMINALISTICS An Introduction to Forensic Science, 9/E By Richard Saferstein 58 Categories of Drugs CNS depressants CNS stimulants Hallucinogens Phencyclidine Inhalants Narcotic analgesics Cannabis

59 10- PRENTICE HALL ©2007 Pearson Education, Inc. Upper Saddle River, NJ 07458 CRIMINALISTICS An Introduction to Forensic Science, 9/E By Richard Saferstein 59 Summary


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