www.it-ebooks.info www.it-ebooks.info BEIJING • CAMBRIDGE • FARNHAM • KÖLN • SEBASTOPOL • TOKYO Illustrated Guide to Home Forensic Science Experiments Robert Bruce Thompson and Barbara Fritchman Thompson First Edition diy Science All Lab, No Lecture www.it-ebooks.info Illustrated Guide to Home Forensic Science Experiments All Lab, No Lecture The O’Reilly logo is a registered trademark of O’Reilly Media, Inc. The DIY Science series designa- tions, Illustrated Guide to Home Forensic Science Experiments: All Lab, No Lecture, and related trade dress are trademarks of O’Reilly Media, Inc. The trademarks of third parties used in this work are the property of their respective owners. Important Message to Our Readers: Your safety is your own responsibility, including proper use of equipment and safety gear, and determining whether you have adequate skill and experience. Chemicals, electricity, and other resources used for these projects are dangerous unless used properly and with adequate precautions, including safety gear. Some illustrative photos do not depict safety precautions or equipment, in order to show the project steps more clearly. These projects are not intended for use by children. Use of the instructions and suggestions in Illustrated Guide to Home Forensic Science Experi- ments: All Lab, No Lecture is at your own risk. O’Reilly Media, Inc., and the authors disclaim all responsibility for any resulting damage, injury, or expense. It is your responsibility to make sure that your activities comply with applicable laws, including copyright. ISBN: 978-1-449-33451-2 [TI] by Robert Bruce Thompson and Barbara Fritchman Thompson Copyright © 2012 Robert Bruce Thompson and Barbara Fritchman Thompson. All rights reserved. Printed in Canada. Published by O’Reilly Media, Inc., 1005 Gravenstein Highway North, Sebastopol, CA 95472. O’Reilly Media books may be purchased for educational, business, or sales promotional use. Online editions are also available for most titles (my.safaribooksonline.com). For more information, contact our corporate/institutional sales department: 800-998-9938 or corporate@oreilly.com. Print History July 2012 First Edition Editor: Brian Jepson Production Editor: Melanie Yarbrough Copy Editor: Bob Russell, Octal Publishing, Inc. Proofreader: Linley Dolby Indexer: Bob Pfahler Cover Designer: Mark Paglietti Cover Photograph: Robert Bruce Thompson Interior Designer: Ron Bilodeau Illustrator: Rebecca Demarest www.it-ebooks.info To Edmond Locard (1877 - 1966), often called the French Sherlock Holmes, who, as a professor of forensic medicine and criminology at the University of Lyons, in 1910 established the world’s first police crime laboratory. Locard’s lab occupied two attic rooms staffed by two assistants provided grudgingly by the Lyons police department, and was initially less well equipped than the home forensics lab we used in writing this book. Despite these limited resources, Locard’s results soon convinced police departments worldwide, including Scotland Yard and the FBI, to found their own crime labs. Locard was the first to state the fundamental principle of forensic science, now known as Locard’s Exchange Principle: “Wherever he steps, whatever he touches, whatever he leaves, even unconsciously, will serve as a silent witness against him. Not only his fingerprints or his footprints, but his hair, the fibers from his clothes, the glass he breaks, the tool mark he leaves, the paint he scratches, the blood or semen he deposits or collects. All of these and more bear mute witness against him. This is evidence that does not forget. It is not confused by the excitement of the moment. It is not absent because human witnesses are. It is factual evidence. Physical evidence cannot be wrong, it cannot perjure itself, it cannot be wholly absent. Only human failure to find it, study and understand it, can diminish its value.” www.it-ebooks.info www.it-ebooks.info Contents v Contents Preface xiii 1 Laboratory Safety 1 2 Equipping Your Forensics Laboratory 5 Optical Equipment 5 Laboratory Equipment 13 Chemicals and Reagents 19 Specimens 26 Group I Soil Analysis 31 Lab I-1 Gather and Prepare Soil Samples 35 Equipment and Materials 35 Background 36 Procedure I-1-1: Gather Soil Specimens 37 Procedure I-1-2: Dry Soil Specimens 38 Review Questions 40 Lab I-2 Examine the Physical Characteristics of Soil 43 Equipment and Materials 43 Background 44 Procedure I-2-1: Observe and Categorize Soil Color 44 Procedure I-2-2: Determine Soil Density 46 Procedure I-2-3: Determine Soil Settling Time 48 Procedure I-2-4: Determine Soil Particle Size Distribution 49 Review Questions 52 Lab I-3 Examine the Microscopic Characteristics of Soil 55 Equipment and Materials 55 Background 56 Procedure I-3-1: Examine Soil Specimens under Magnification 57 Review Questions 58 Lab I-4 Assay Phosphate Concentrations in Soil Specimens 61 Equipment and Materials 61 Background 62 Procedure I-4-1: Extract Soil Specimens 63 Procedure I-4-2: Assay Soil Phosphate Concentrations 64 Review Questions 65 www.it-ebooks.info vi DIY Science: Illustrated Guide to Home Forensic Science Experiments Lab I-5 Examine the Spectroscopic Characteristics of Soil 67 Equipment and Materials 67 Background 68 Procedure I-5-1: Extract Ion Species from Soil Specimens 69 Procedure I-5-2: Test Soil Specimen Extracts with the Spectrometer 69 Procedure I-5-3: Identify Ions Present in Exemplar 72 Review Questions 73 Group II Hair and Fiber Analysis 75 Lab II-1 Gathering Hair Specimens 79 Equipment and Materials 79 Background 80 Procedure II-1-1: Obtain Hair Specimens with Forceps 81 Procedure II-1-2: Obtain Hair Specimens with Lift Tape 82 Review Questions 83 Lab II-2 Study the Morphology of Human Scalp Hair 85 Equipment and Materials 85 Background 86 Procedure II-2-1: Macroscopic Examination of Human Scalp Hair 87 Procedure II-2-2: Wet-Mount Hair Specimens 88 Procedure II-2-3: Microscopic Examination of Human Scalp Hair 89 Review Questions 91 Lab II-3 Make Scale Casts of Hair Specimens 93 Equipment and Materials 93 Background 93 Procedure II-3-1: Make and Observe Scale Casts of Human Hair 95 Review Questions 96 Lab II-4 Study the Morphology of Animal Hair 99 Equipment and Materials 99 Background 100 Procedure II-4-1: Observe Animal Hair 101 Review Question 101 Lab II-5 Individualize Human Hair Specimens 103 Equipment and Materials 103 Background 104 Procedure II-5-1: Obtain Hair Specimens 105 Procedure II-5-2: Observe and Characterize Hair Specimens 105 Review Questions 106 Lab II-6 Physical and Chemical Tests of Fibers 109 Equipment and Materials 109 Background 110 Procedure II-6-1: Test Fiber Specimens by Burning 111 Procedure II-6-2: Test Fiber Specimens by Solubility 115 Procedure II-6-3: Test Fiber Specimens by Dye Stripping 118 www.it-ebooks.info Contents vii Procedure II-6-4: Test Fiber Specimens by Dyeing 120 Review Questions 122 Lab II-7 Study the Morphology of Fibers and Fabrics 127 Equipment and Materials 127 Background 128 Procedure II-7-1: Macroscopic Examination of Fabrics 129 Procedure II-7-2: Microscopic Examination of Fibers and Fabrics 130 Procedure II-7-3: Cross-Sectional Examination of Fiber Specimens 132 Procedure II-7-4: Determine the Refractive Index of Fibers with RI Matching Liquids 134 Procedure II-7-5: Examining Fibers by Polarized Light 139 Review Questions 141 Group III Glass and Plastic Analysis 145 Lab III-1 Determine Densities of Glass and Plastic Specimens 149 Equipment and Materials 149 Background 150 Procedure III-1-1: Determine Density by Displacement 152 Procedure III-1-2: Determine Density by Flotation 153 Review Questions 154 Lab III-2 Compare Refractive Indices of Glass and Plastic Specimens 157 Equipment and Materials 157 Background 158 Procedure III-2-1: Compare RI of Questioned and Known Specimens 159 Review Question 160 Lab III-3 Observe Shatter Patterns 163 Equipment and Materials 163 Background 164 Procedure III-3-1: Produce Glass Shards 164 Procedure III-3-2: Observe and Compare Glass Shards 165 Review Questions 165 Group IV Revealing Latent Fingerprints 167 Lab IV-1 Dusting and Lifting Latent Fingerprints 177 Equipment and Materials 177 Background 177 Procedure IV-1-1: Dusting Latent Fingerprints 178 Procedure IV-1-2: Lifting Developed Fingerprints 179 Review Questions 180 Lab IV-2 Revealing Latent Fingerprints Using Iodine Fuming 183 Equipment and Materials 183 Background 184 Procedure IV-2-1: Fuming Latent Fingerprints with Iodine 185 Review Questions 187 www.it-ebooks.info viii DIY Science: Illustrated Guide to Home Forensic Science Experiments Lab IV-3 Revealing Latent Fingerprints Using Ninhydrin 189 Equipment and Materials 189 Background 190 Procedure IV-3-1: Developing Latent Fingerprints with Ninhydrin 191 Procedure IV-3-2: Ninhydrin After-Treatments 192 Review Questions 193 Lab IV-4 Revealing Latent Fingerprints Using Superglue Fuming 197 Equipment and Materials 197 Background 198 Procedure IV-4-1: Preparing for Superglue Fuming 199 Procedure IV-4-2: Fuming Latent Fingerprints with Superglue 199 Procedure IV-4-3: Dusting and Lifting Superglue-fumed Fingerprints 200 Review Questions 201 Lab IV-5 Revealing Latent Fingerprints On Sticky Surfaces 203 Equipment and Materials 203 Background 204 Procedure IV-5-1: Preparing Specimens for Gentian Violet Development 205 Procedure IV-5-2: Developing Specimens with Gentian Violet 205 Review Questions 207 Lab IV-6 Revealing Latent Fingerprints On Brass Cartridge Cases 209 Equipment and Materials 209 Background 210 Procedure IV-6-1: Treat Specimens with Acidified Hydrogen Peroxide 210 Review Question 211 Group V Detecting Blood 213 Lab V-1 Testing the Sensitivity and Selectivity of Kastle-Meyer Reagent 217 Equipment and Materials 217 Background 218 Procedure V-1-1: Prepare Known Dilutions of Blood 219 Procedure V-1-2: Spot Known Dilutions of Blood 220 Procedure V-1-3: Test Sensitivity of Kastle-Meyer Reagent 221 Procedure V-1-4: Test Selectivity of Kastle-Meyer Reagent 222 Procedure V-1-5: Field Testing with Kastle-Meyer Reagent 222 Review Questions 223 Group VI Impression Analysis 227 Lab VI-1 Tool Mark Analysis 231 Equipment and Materials 231 Background 232 Procedure VI-1-1: Produce and Compare Compression Specimens 233 Procedure VI-1-2: Produce and Compare Scoring Specimens 235 Review Questions 236 www.it-ebooks.info [...]... 407 xii DIY Science: Illustrated Guide to Home Forensic Science Experiments www.it-ebooks.info Preface You’re reading this preface, so it’s a fair assumption that you’re interested in forensic science You’re in good company For more than 100 years, forensic science has fascinated a lot of people Popular interest in forensic science started with the detective stories of Edgar Allen Poe... a disposable respirator mask if you handle chemicals that are toxic by inhalation 2 DIY Science: Illustrated Guide to Home Forensic Science Experiments www.it-ebooks.info Avoid laboratory hazards Don’t Do Stupid Things • Avoid chemical hazards • Never eat, drink, or smoke in the laboratory Never taste any laboratory chemical or sniff it directly (Use your hand to waft the odor toward your nose.) Never... xvi DIY Science: Illustrated Guide to Home Forensic Science Experiments www.it-ebooks.info analysis He has worked in the forensic field since 1980 He was appointed acting director of the State Crime Laboratory in 1992, appointed to the director’s position in 1995, and has held a position in the University of Rhode Island College of Pharmacy as an adjunct assistant professor of biomedical sciences... scientists are at what they do, how persistent and inventive they have to be, and just how hard they work to get the job done Welcome to the world of real forensics xiv DIY Science: Illustrated Guide to Home Forensic Science Experiments www.it-ebooks.info Individual versus Class Evidence Throughout this book, we refer to the two categories of forensic evidence Individual evidence is evidence—such as a fingerprint... contains links to equipment kits customized for this book, corrections and errata, supplemental material that didn’t make it into the book, and so on Visit this page before you buy any equipment or chemicals and before you do any of the experiments Revisit it periodically as you use the book www.thehomescientist.com/forensics Thank You Thank you for buying Illustrated Guide to Home Forensic Science Experiments. .. directly, send mail to: robert@thehomescientist.com barbara@thehomescientist.com Preface xvii www.it-ebooks.info We read all mail we receive from readers, but we cannot respond individually If we did, we’d have no time to do anything else But we do like to hear from readers We also maintain a dedicated landing page on our main website to support Illustrated Guide to Home Forensic Science Experiments This... need to equip your forensics lab and work safely in your lab II Laboratory: Hair and Fiber Analysis III Laboratory: Glass and Plastic Analysis 1 Laboratory Safety IV Laboratory: Revealing Latent Fingerprints 2 Equipping a Forensics Lab V Laboratory: Blood Detection The bulk of the book is made up of the following 11 hands-on laboratory chapters, each devoted to a particular topic Each of the laboratory... vendors, drugstores Mounting fluids for temporary mounts ● drugstores, supermarkets Scanner with software (optional) ○ Local/online vendors Spectrometer (optional) ○ See text Ultraviolet light source ○ See text 12 DIY Science: Illustrated Guide to Home Forensic Science Experiments www.it-ebooks.info Laboratory Equipment In designing the lab sessions for this book, we made every effort to keep equipment... O’Reilly website for Illustrated Guide to Home Forensic Science Experiments lists examples, errata, and plans for future editions You can find this page at: http://oreil.ly /home_ forensic_ science_ exp MAKE unites, inspires, informs, and entertains a growing community of resourceful people who undertake amazing projects in their backyards, basements, and garages MAKE celebrates your right to tweak, hack, and... Robert, the co-author of numerous books about computers, science, and technology With her masters in library science and 20 years’ experience as a public librarian, Barbara is the research half of our writing team xviii DIY Science: Illustrated Guide to Home Forensic Science Experiments www.it-ebooks.info www.it-ebooks.info www.it-ebooks.info Laboratory Safety 1 First things first This is a short chapter, . purposes. www.it-ebooks.info xvi DIY Science: Illustrated Guide to Home Forensic Science Experiments We consider forensics to be the ideal introductory lab-based science course. mail to: robert@thehomescientist.com barbara@thehomescientist.com www.it-ebooks.info xviii DIY Science: Illustrated Guide to Home Forensic Science Experiments We