Forensic Chemistry. Fundamentals and Applications

Description

Forensic Chemistry is a comprehensive overview of the subject aimed at those students who have a basic understanding of the underlying principles and are looking for a more detailed reference text. This book is aimed at advanced students who are studying forensic science or analytical chemistry, faculty and researchers, and practitioners such as crime laboratory bench scientists. The authors will assume that the reader will have an introductory knowledge of forensic science and forensic chemistry and will have had analytical, organic and instrumental chemistry. None of the major analytical chemical techniques will have separate treatments in the book, with the exception of forensic microscopy, which will have a chapter because many students in chemistry and forensic science do not get dedicated classes in this area. The book will have separate chapters on all of the major areas of forensic chemistry and, in addition, will have a chapter devoted to chemometrics, which is the statistical treatment of large amounts of data to discover groupings, similarities and differences among the data. Each chapter will be written by an acknowledged international expert in that area. Each author will be given detailed instructions as to the intended audience, as well as expected breadth and depth of coverage of the material in the hopes that this will minimize the problem of uneven coverage of topics and chapters that often occurs in edited books. Although each of the types of evidence covered in the book use methods of analysis that lie outside chemistry, these will be mentioned only for completeness in passing. The emphasis will be on the use of chemical tools in evidence analysis.

This book is designed to be either a text book for an advanced forensic chemistry course, or a treatise in forensic chemistry for the scientist who wants to learn the subject in some depth. It is not designed to be a survey of the current literature in the field or a reference manual.

Table of Contents

About the editor
Contributors,
Series preface
Preface

1 Drugs of abuse, 1
Niamh Nic Daéid
1.1 Introduction, 1
1.2 Law and legislation, 2
1.3 Sampling, 4
1.3.1 Random sampling and representative sampling, 6
1.3.2 Arbitrary sampling, 7
1.3.3 Statistical sampling methods, 8
1.4 Specific drug types, 9
1.4.1 Cannabis, 9
1.4.2 Heroin, 14
1.4.3 Cocaine, 22
1.4.4 Amphetamine ]type stimulants, 27
1.4.5 New psychoactive substances, 33
1.5 Conclusions, 36
Acknowledgements, 36
References, 36

2 Textiles, 40
Max Houck
2.1 Introduction, 40
2.2 A science of reconstruction, 40
2.2.1 Classification, 41
2.2.2 Comparison, 42
2.2.3 Transfer and persistence, 43
2.3 Textiles, 43
2.3.1 Information, 44
2.3.2 Morphology, 45
2.4 Natural fibers, 48
2.4.1 Animal fibers, 48
2.4.2 Plant fibers, 51
2.5 Manufactured fibers, 52
2.6 Yarns and fabrics, 55
2.6.1 Fabric construction, 56
2.6.2 Finishes, 59
2.7 Fiber types, 59
2.7.1 Acetate, 59
2.7.2 Acrylic, 59
2.7.3 Aramids, 60
2.7.4 Modacrylic, 60
2.7.5 Nylon, 61
2.7.6 Olefins (polypropylene and polyethylene), 61
2.7.7 Polyester, 62
2.7.8 Rayon, 62
2.7.9 Spandex, 65
2.7.10 Triacetate, 66
2.7.11 Bicomponent fibers, 66
2.8 Chemistry, 67
2.8.1 General analysis, 67
2.8.2 Instrumental analysis, 68
2.8.3 Color, 69
2.8.4 Raman spectroscopy, 70
2.8.5 Interpretation, 71
2.9 The future, 72
References, 72

3 Paint and coatings examination, 75
Paul Kirkbride
3.1 Introduction, 75
3.2 Paint chemistry, 76
3.2.1 Binders, 76
3.2.2 Dyes and pigments, 86
3.2.3 Additives, 89
3.3 Automotive paint application, 91
3.4 Forensic examination of paint, 92
3.4.1 General considerations, 92
3.4.2 Microscopy, 95
3.4.3 Vibrational spectrometry, 96
3.4.4 SEM ]EDX and XRF, 106
3.4.5 Pyrolytic techniques, 111
3.4.6 Color analysis, 116
3.5 Paint evidence evaluation and expert opinion, 120
References, 128

4 Forensic fire debris analysis, 135
Reta Newman
4.1 Introduction, 135
4.2 Process overview, 135
4.3 Sample collection, 136
4.4 Ignitable liquid classification, 137
4.5 Petroleum ]based ignitable liquids, 144
4.6 Non ]petroleum ]based ignitable liquids, 160
4.7 Sample preparation, 161
4.8 Sample analysis and data interpretation, 166
4.9 Summary, 172
References, 173

5 Explosives, 175
John Goodpaster
5.1 The nature of an explosion, 175
5.1.1 Types of explosions, 175
5.1.2 Explosive effects, 176
5.2 Physical and chemical properties of explosives, 180
5.2.1 Low explosives, 181
5.2.2 High explosives, 186
5.3 Protocols for the forensic examination of explosives and explosive devices, 192
5.3.1 Recognition of evidence, 192
5.3.2 Portable technology and on ]scene analysis, 193
5.3.3 In the laboratory, 194
5.4 Chemical analysis of explosives, 200
5.4.1 Consensus standards (TWGFEX), 201
5.4.2 Chemical tests, 203
5.4.3 X ]ray techniques, 204
5.4.4 Spectroscopy, 207
5.4.5 Separations, 212
5.4.6 Gas chromatography, 213
5.4.7 Mass spectrometry, 215
5.4.8 Provenance and attribution determinations, 219
5.5 Ongoing research, 221
Acknowledgements, 222
References, 222
Further reading, 226

6 Analysis of glass evidence, 228
Jose Almirall and Tatiana Trejos
6.1 Introduction to glass examinations and comparisons, 228
6.2 Glass, the material, 231
6.2.1 Physical and chemical properties, 231
6.2.2 Manufacturing, 233
6.2.3 Fractures and their significance, 236
6.2.4 Forensic considerations: Transfer and persistence of glass, 238
6.3 A brief history of glass examinations, 241
6.4 Glass examinations and comparison, standard laboratory practices, 242
6.4.1 Physical measurements, 243
6.4.2 Optical measurements, 244
6.4.3 Chemical measurements: elemental analysis, 247
6.5 Interpretation of glass evidence examinations and comparisons, 256
6.5.1 Defining the match criteria, 256
6.5.2 Descriptive statistics, 256
6.5.3 Match criteria for refractive index measurements, 257
6.5.4 Informing power of analytical methods, forming the opinion, 260
6.5.5 Report writing and testimony, 262
6.6 Case examples, 263
6.6.1 Case 1: Hit ]and ]run case, 263
6.6.2 Case 2: Multiple transfer of glass in breaking ]and ]entry case, 264
6.7 Conclusions, 265
References, 266

7 The forensic comparison of soil and geologic microtraces, 273
Richard E. Bisbing
7.1 Soil and geologic microtraces as trace evidence, 273
7.2 Comparison process, 274
7.3 Developing expertise, 278
7.4 Genesis of soil, 279
7.5 Genesis of geologic microtraces, 284
7.6 Collecting questioned samples of unknown origin, 287
7.7 Collecting soil samples of known origin, 288
7.8 Initial comparisons, 290
7.9 Color comparison, 290
7.10 Texture comparison, 293
7.11 Mineral comparison, 297
7.12 Modal analysis, 301
7.13 Automated instrumental modal analysis, 308
7.14 Ecological constituents, 310
7.15 Anthropogenic constituents, 312
7.16 Reporting comparison results, 312
7.17 Future directions and research, 314
Acknowledgments, 314
References, 315
Further reading, 316

8 Chemical analysis for the scientific examination of questioned documents, 318
Gerald M. LaPorte
8.1 Static approach, 320
8.2 Dynamic approach, 324
8.3 Ink composition, 324
8.4 Examinations, 328
8.4.1 Physical examinations, 329
8.4.2 Optical examinations, 332
8.4.3 Chemical examinations, 333
8.4.4 Paper examinations, 339
8.5 Questioned documents, crime scenes and evidential considerations, 342
8.5.1 How was the questioned document produced?, 342
8.5.2 What evidence can be used to associate a questioned document with the crime scene and/or victim?, 343
8.5.3 Are there other forensic examinations that can be performed?, 345
8.5.4 Demonstrating that a suspect altered a document, 346
8.6 Interpreting results and rendering conclusions, 347
References, 350

9 Chemical methods for the detection of latent fingermarks, 354
Amanda A. Frick, Patrick Fritz, and Simon W. Lewis
9.1 Introduction, 354
9.2 Sources of latent fingermark residue, 355
9.2.1 Aqueous components, 356
9.2.2 Lipid components, 357
9.2.3 Sources of compositional variation, 359
9.3 Chemical processing of latent fingermarks, 361
9.3.1 Amino acid sensitive reagents, 361
9.3.2 Reagents based on colloidal metals, 370
9.3.3 Lipid ]sensitive reagents, 377
9.3.4 Other techniques, 383
9.4 Experimental considerations for latent fingermark chemistry research, 384
9.5 Conclusions and future directions, 387
Acknowledgements, 388
References, 388
Further reading, 398

10 Chemical methods in firearms analysis, 400
Walter F. Rowe
10.1 Introduction, 400
10.2 Basic firearms examination, 400
10.2.1 Cleaning bullets and cartridges, 402
10.2.2 Analysis of bullet lead, 404
10.2.3 Serial number restoration, 406
10.3 Shooting incident reconstruction, 408
10.3.1 Muzzle ]to ]target determinations, 411
10.3.2 Firearm primers, 416
10.3.3 Collection of gunshot residue, 425
10.4 Conclusion, 433
References, 433

11 Forensic microscopy, 439
Christopher S. Palenik
11.1 The microscope as a tool, 439
11.2 Motivation, 440
11.2.1 Intimidation, 442
11.2.2 Limitations, 442
11.3 Scale, 442
11.3.1 Scale and magnification, 443
11.3.2 Noting scale, 443
11.3.3 Analytical volume and limits of detection, 443
11.4 Finding, 445
11.4.1 Spatial resolution, 445
11.4.2 Recovery resolution, 447
11.4.3 Stereomicroscope, 447
11.5 Preparing, 448
11.5.1 Preservation and documentation, 448
11.5.2 Isolation, 450
11.5.3 Mounting, 451
11.6 Looking, 455
11.6.1 Light microscopy, 456
11.6.2 Scanning electron microscopy, 457
11.7 Analyzing, 458
11.7.1 Polarized light microscopy, 458
11.7.2 Energy dispersive X ]ray spectroscopy, 462
11.7.3 FTIR and Raman spectroscopy, 464
11.7.4 Other methods, 465
11.8 Thinking, 465
11.9 Thanking, 467
References, 467

12 Chemometrics, 469
Ruth Smith
12.1 Introduction, 469
12.2 Chromatograms and spectra as multivariate data, 470
12.3 Data preprocessing, 470
12.3.1 Baseline correction, 471
12.3.2 Smoothing, 473
12.3.3 Retention ]time alignment, 473
12.3.4 Normalization and scaling, 475
12.4 Unsupervised pattern recognition, 477
12.4.1 Hierarchical cluster analysis, 478
12.4.2 Principal components analysis, 480
12.5 Supervised pattern recognition procedures, 485
12.5.1 k ]Nearest neighbors, 486
12.5.2 Discriminant analysis, 487
12.5.3 Soft independent modeling of class analogy, 492
12.5.4 Model validation, 493
12.6 Applications of chemometric procedures in forensic science, 494
12.6.1 Fire debris and explosives, 495
12.6.2 Controlled substances and counterfeit medicines, 496
12.6.3 Trace evidence, 497
12.6.4 Impression evidence, 499
12.7 Conclusions, 499
Acknowledgements, 500
References, 500

Index, 504