CRIME SCENE FORENSICS A SCIENTIFIC METHOD APPROACHPDF电子书下载

Part Ⅰ THE PHILOSOPHY AND ESSENTIALS OF CRIME SCENE FORENSICS 3

1 Crime Scene Forensics: Philosophy, Practice, and Teaching 3

1.1 Introduction 3

1.2 Why Investigate the Crime Scene? 4

1.3 Who Should Investigate Scenes of Crimes? 5

1.3.1 Crime Scene Investigative Paradigms 6

1.3.1.1 The Current Paradigm 7

1.3.1.2 An Evolving Paradigm 7

1.4 Definitions: Crime Scene, Forensic Science, Criminalistics, Forensics 13

1.4.1 Crime Scene 13

1.4.2 Forensic Science 14

1.4.3 Criminalistics 15

1.4.3.1 The Forensic DNA Biologist 18

1.4.3.2 The Medical Examiner 18

1.4.3.3 The Forensic Street Drug Chemist 18

1.4.3.4 The Bloodstain Pattern Analysis Expert 18

1.4.3.5 The Crime Scene Investigator 19

1.4.4 Forensics 19

1.5 The Concept of Evidence 20

1.5.1 Perceptions of Evidence 20

1.5.2 Divisible Matter and the Transfer of Evidence 22

1.5.3 The Human Mind and the Recognition of Evidence 23

1.5.4 The Legal Perspective/Connection 24

1.5.5 Defining Evidence 25

1.6 Instruction: A Philosophy 26

1.6.1 Structure of the Instruction 27

References 29

2 The Scientific Method, Bias, and Reasoning 31

2.1 Introduction 31

2.2 The Scientific Method: Scene Scientists and Scene Investigators 32

2.3 Bias in Scene Investigations 37

2.3.1 Case Example 1 40

2.3.2 Case Example 2 40

2.4 Reasoning 44

References 46

3 Management Basics: The Investigative Glue 47

3.1 Introduction 47

3.1.1 Teaching Crime Scene Management 47

3.1.2 The Learning Process 48

3.2 The Responding Officer 49

3.2.1 Observations 49

3.2.2 Actions 51

3.2.3 Documentation 53

3.3 The Team Leader: Managing the Scene Investigation 53

3.3.1 Subteams 55

3.4 The Scene Processing Cascade 57

3.4.1 Integrating the Scientific Method 60

References 62

4 The Fundamental Principles of Evidence 63

4.1 Introduction 63

4.2 The Locard Exchange Principle: "Every Touch Leaves a Trace" 63

4.3 Divisible Matter 65

4.4 Evidence Dynamics 68

4.5 Crime Scene Elements 69

4.5.1 The Macroscene 70

4.5.2 The Microscene: Trace Evidence or Locard Elements 73

4.5.2.1 The Transfer of Microscene Elements 75

4.6 Scene Scenario 80

References 84

5 Searching the Scene: Logic in Action 87

5.1 Introduction 87

5.2 Processing versus Investigation 89

5.3 Defining the Search 90

5.3.1 Effective Management 91

5.3.2 Nature of the Scene 91

5.3.3 Logic 92

5.3.4 Systematic 93

5.3.5 Creative Thinking--Out of the Box 93

5.4 Scene Search Methods 93

5.4.1 The Line (Grid) Methods 95

5.4.1.1 The Sequence of an Outdoor Search--Archiving and Searching Using the Grid Method 97

5.4.1.2 Zone and Point-to-Point Searches 98

5.4.1.3 The Link Method 100

5.4.1.4 Ray or Wheel Search 100

5.5 Employing On-Scene Technology and/or Statements 101

5.6 Pressures at the Scene 101

5.6.1 Constraints 102

5.7 Archiving and Searching Common Scene Types 102

5.8 Technology to Aid Searching 102

5.9 Searching for Trace Evidence--Overview Considerations 102

References 105

Part Ⅱ FORENSIC ARCHIVING: TODAY'S EYE FOR THE FUTURE 109

6 The Principles of Forensic Photography 109

6.1 Introduction to Forensic Archiving 109

6.1.1 Passive Archiving 110

6.1.2 Active Archiving 110

6.2 Techniques of Forensic Archiving 111

6.2.1 Digital Forensic Photography (Photographic Archiving) 111

6.2.2 The Purpose of Forensic Photography 112

6.2.3 Critical Aspects of Forensic Photography 113

6.3 The SLR Digital Camera 113

6.4 Essential Skills of Forensic Photography 115

6.4.1 Focus: "If It's Not in Focus, the Rest Doesn't Matter" 115

6.4.2 The Correct Forensic Exposure 116

6.4.2.1 Equivalent Exposures 117

6.4.3 Aperture 118

6.4.3.1 Telling the Scene's Story: The Importance of Aperture 120

6.4.4 Shutter Speed 122

6.4.5 Exposure Values 123

6.4.6 International Organization for Standardization (ISO) 124

6.4.7 Focal Length 124

6.4.8 Metering 125

6.4.9 Exposure Compensation 126

6.4.10 White Balance 126

6.4.11 Capturing Forensic Content Properly 128

6.5 Forensic Aspects of Photography 129

6.5.1 Scene Incident Photographic Worksheet 130

6.5.2 Photographic Log 130

6.5.3 Types of Photographs 130

6.5.3.1 Establishing--Overview or Overall--Photographs 130

6.5.3.2 Midrange Photographs 132

6.5.3.3 Close-Up Photographs 133

6.5.4 Illumination 133

6.5.5 Filters 136

6.6 Forensic-Specific Considerations 136

6.6.1 Camera Positions 136

6.6.2 Scales 138

6.7 Photography of Common Scene Scenarios 138

6.7.1 Vehicular Accidents 139

6.7.2 Homicide Scenes 140

6.7.3 Nonhomicide Sexual Assaults 143

6.7.4 Suicides 144

6.7.5 Hit-and-Run Cases 146

6.7.6 Fatal Accidents: Body inside the Vehicle 146

6.7.7 Burglary: Breaking and Entering 146

6.7.8 Fire Scenes: Arson 147

6.8 Special Photographic Situations 147

6.8.1 Night and Low-Light Scenes 148

6.8.1.1 Painting with Light 148

6.8.1.2 Slaves 149

6.8.2 Impression Evidence Photography 149

6.8.3 Close-Up Photography 152

6.8.3.1 Image in the Viewfinder 152

6.8.3.2 The Close-Up Lens 152

6.8.3.3 Illumination 153

6.8.3.4 Depth of Field 154

6.8.3.5 Focus 154

6.8.3.6 Scales 154

References 154

Workshop 1: Photography--Camera Basics 155

W 1.1 Introduction 155

W 1.2 Required Tools 156

W 1.3 Camera Basics 156

W 1.3.1 File Formats 156

W 1.3.2 Camera Function Dials and Menu Options 156

W 1.4 Exercise 1 157

W 1.4.1 Aperture Priority 157

W 1.4.2 Shutter Speed 159

W 1.4.3 Manual Priority 159

W 1.5 Dark Environment Photography 160

W 1.5.1 ISO 160

W 1.5.2 Painting with Light or Using Slaves 161

W 1.6 Close-Up Photography 161

W 1.6.1 Procedure 162

W 1.6.2 Questions 162

7 The Paper Trail: Case Files, Worksheets, Notes, and Sketches 163

7.1 Introduction: General Considerations 163

7.2 Case Files 163

7.2.1 Worksheets 164

7.2.1.1 Forms 164

7.2.1.2 Mistakes 167

7.3 Sketches 167

7.3.1 Indoor Sketch Types 169

7.3.1.1 Plan Sketch 169

7.3.1.2 Cross-Projection or Exploded Sketch 170

7.3.1.3 Elevation Sketch 171

7.3.1.4 Perspective Sketch: 3D Rendering of a Scene 171

7.3.2 Outdoor Sketches 172

7.4 Measuring the Scene 172

7.4.1 Locating Objects 173

7.4.1.1 Triangulation 173

7.4.1.2 Baseline Method 174

7.4.2 Photogrammetry 177

7.4.3 Outdoor Scene Measurements 177

7.5 Securing the Archive 179

References 183

Workshop 2: Sketching the Scene 183

W 2.1 Introduction 183

W 2.2 Required Tools 183

W 2.2.1 Indoor Tools 184

W 2.2.2 Outdoor Tools 184

W 2.3 General Methods for Measuring the Scene 184

W 2.3.1 Triangulation 184

W 2.3.2 The Baseline Method 184

W 2.4 Indoor Scene Measurements 184

W 2.5 Outdoor Scene Measurements 185

W 2.6 Instructor Demonstration 185

W 2.7 Exercises 185

W 2.7.1 An Outdoor Scene 185

W 2.7.2 An Indoor Scene 185

W 2.8 Questions 188

8 Videography: The Forensic Documentary 189

8.1 Introduction 189

8.1.1 The Forensic Value of Crime Scene Video 189

8.1.1.1 Objective of the Video 190

8.1.2 Crime Scene Video Is a Documentary 190

8.1.3 Basic Video Terminology 190

8.1.4 Essential Video Camera Features 191

8.1.5 Requirements of a Forensic Videographer 192

8.1.5.1 Camera Movement Terminology 192

8.2 Basic Forensic Videography: The Scene Video 193

8.2.1 Camera Speed and Position 194

8.2.2 Camera Distances and Angles 194

8.2.3 Establishing Video Shows the Backdrop of the Scene 194

8.2.4 Close-Up Detail 194

8.3 The Forensic Topic Video and Forensic Photography 195

8.4 The Prescene Checklist 196

8.5 On-Scene Fundamentals 197

References 197

Part Ⅲ IMPRESSION EVIDENCE: PATTERNS OF IDENTITY 201

9 Fingerprints Ⅰ: The Intellectual Ingredients 201

9.1 Introduction 201

9.2 A Reasoned, Scientific Approach 203

9.2.1 On-Scene Printing: Menu-Driven versus Logic-Based Approaches 203

9.2.1.1 The Scene 204

9.2.1.2 Surface Characteristics 204

9.2.1.3 Environmental Conditions and the Age of the Print 206

9.2.1.4 The Tools 206

9.2.1.5 Resources 207

9.2.1.6 Technology and Its Limitations 207

9.2.1.7 Logic 208

9.2.1.8 Knowledge of the Science 209

9.2.1.9 Experience 209

9.2.1.10 Critical Thinking 209

9.2.1.11 Out-of-the-Box Reasoning 209

References 210

10 Fingerprints Ⅱ: On-Scene Considerations 211

10.1 Introduction 211

10.2 The Glandular Origin of Fingerprints 212

10.3 Finding Fingerprints at Scenes: General Considerations 215

10.4 Fingerprint Development Strategies 215

10.4.1 Porous Surfaces 217

10.4.1.1 Fingerprint Penetration into the Surface Matrix 217

10.4.1.2 Fingerprint Development Cascades for Porous Surfaces 218

10.4.2 Nonporous Surfaces 222

10.4.2.1 Powder Dusting 223

10.5 Fingerprints and DNA 226

10.5.1 Superglue (Cyanoacrylate) Fuming 226

10.5.1.1 Chemistry of the Cyanoacrylate Reaction 227

10.5.1.2 Superglue Fuming Methods 228

10.6 Lifting Developed Prints 234

10.6.1 Powder Lifts 234

10.6.1.1 Surface 234

10.7 Fingerprints on Adhesive Tapes 237

10.7.1 Removing Tape from Its Substrate 237

10.7.1.1 Physical Processes 238

10.7.1.2 Cooling 238

10.7.1.3 Freezer Spray 238

10.7.1.4 Solvents 238

10.7.2 Packaging and Protecting Adhesive Tapes 239

10.7.3 Developing Fingerprints on the Adhesive Side of Tapes 239

10.7.3.1 Rubber-Based Adhesives 240

10.7.3.2 Acrylic-Based Adhesives 241

10.7.3.3 Spot Testing Adhesives [32] 242

10.8 Patent Prints 242

10.8.1 Strategy One 242

10.8.2 Strategy Two 243

10.9 Impression Evidence in Blood 245

10.9.1 Blood as Multitasking Evidence 246

10.9.1.1 HOSDB Formulation for Acid Black 1, Acid Violet 17, and Acid Yellow 7 249

10.9.1.2 FBI Formulation for Acid Black 1 249

10.9.1.3 General Protein Fixing Procedure 250

10.9.1.4 General Procedure for Staining Blood Impressions 250

10.9.1.5 General Procedure for On-Scene Blood Print Staining 251

10.10 Fingerprints and Heat: Fire Scenes 251

10.10.1 Effect of Heat on Fingerprints 252

10.10.2 Locating Fingerprints at Arson Scenes 253

10.10.3 On-Scene Activity 254

References 254

Workshop 3: Fingerprints on Nonporous Surfaces--Dusting Powders 256

W 3.1 Inked and Rolled Prints 256

W 3.2 Developing Fingerprints at the Scene Using Dusting Powders 256

W 3.3 Fingerprint Residue 257

W 3.3.1 General Guidelines for Print Development 257

W 3.3.2 Powders Available 257

W 3.3.3 Demonstration 258

W 3.3.4 Exercise 1: Dusting Nonporous Surfaces 258

W 3.3.5 Exercise 2: Finding and Lifting Latent Fingerprints in a Mock Scene 259

W 3.4 Fingerprints on Wet Surfaces 259

W 3.4.1 Demonstration 259

W 3.5 Prints on the Sticky Side of Adhesive Tapes 260

W 3.5.1 Sticky-Side Fingerprint Developing Reagents 260

W 3.5.2 Spot Testing the Sticky-Side Chemistry 260

W 3.5.3 Exercise 4: Finding Prints on the Sticky Side of Adhesive Tape 261

W 3.6 Lifting Fingerprints 261

W 3.6.1 Tape-Lifting Procedure 261

W 3.6.2 Exercise 5: Lifting Dusted Fingerprints 262

W 3.7 Fluorescent Powders 262

W 3.7.1 Demonstration 262

W 3.7.2 Exercise 6 262

W 3.8 MikrosilTM Casting--Tex-Liff--Gellifters 263

W 3.8.1 Demonstration for Lifting Black and Dual-Dusted Fingerprints 263

W 3.8.2 Exercise 8: Lifting Prints Using Gels and MikrosilTM Casts 263

W 3.9 Prints on Skin: Demonstration 263

W 3.10 Finding Prints at the Scene: Demonstration 264

W 3.10.1 Reflected Ultraviolet Light 265

W 3.10.2 Alternate Light Source 265

W 3.10.3 Oblique Lighting 265

Workshop 4: Fingerprints on Nonporous (Continued) and Porous Surfaces 265

W 4.1 Nonporous Surfaces (Continued) 265

W 4.1.1 Super Glue Fuming and Enhancement: Background 265

W 4.1.2 Prints on Metallic Surfaces: Corrosion Analysis 267

W 4.2 Porous Surfaces 268

W 4.2.1 Exercise 1: Iodine Fuming 268

W 4.2.2 Exercise 2: Ninhydrin-Developed Fingerprints 269

W 4.2.3 Exercise 3: DFO-Developed Prints 269

W 4.2.4 Exercise 4: 1,2-Indanedione-Developed Prints 270

W 4.2.5 Exercise 5: Heat-Developed Prints 270

W 4.2.6 Exercise 6: Lanthanide-Developed Prints 270

W 4.3 Questions 271

11 Pattern Evidence Ⅰ: Footwear Impressions 273

11.1 Introduction 273

11.2 General Characteristics of Impression Evidence 273

11.3 Footwear Impressions (Marks) 274

11.3.1 Is Footwear Evidence Important? 274

11.3.2 CLassifying Footwear Impressions 278

11.3.3 Scene Investigation versus Laboratory Processes 279

11.3.4 Likelihood That Footwear Impressions Are Present 280

11.3.5 Finding Footwear Evidence at the Scene 281

11.3.6 Common Footwear Transfers 282

11.3.7 Enhancing Footwear Impressions: Understanding the Composition of Dust and Soil 283

11.4 2D Impression Evidence 284

11.4.1 Finding 2D Footwear Impressions at the Scene 285

11.4.1.1 Using Light to Locate Impression Evidence 285

11.5 Dry Residue Impressions 286

11.5.1 Science of Lifting Dry and Wet Residue Prints 287

11.5.1.1 Electrostatic Lifting 287

11.5.1.2 Gelatin Lifters/Gel Lifters (Gellifters) 289

11.6 Wet Residue Impressions 291

11.6.1 Enhancing Wet Residue Impressions 291

11.7 Visible (Patent) Impressions: Contaminating Substances 292

11.8 Preserving Enhanced Footwear Impressions 294

11.9 3D Impression Evidence 295

11.9.1 Photographic Archiving of 3D Impression Evidence 297

11.9.2 Casting to Preserve 3D Impression Evidence 297

11.9.2.1 Materials Required 300

11.9.2.2 Preparing the Impression 301

11.9.2.3 General Casting Procedure 301

11.9.2.4 Lifting the Cast 302

11.9.3 Special Circumstances 302

11.9.3.1 Casting in Snow 302

11.9.3.2 Snow Casting Procedure 302

References 303

12 Pattern Evidence Ⅱ: Vehicle-Involved Scenes 305

12.1 Introduction 305

12.2 Vehicle-Involved Scenes 305

12.2.1 Tire Track Impression Evidence: Evidence Often Overlooked 306

12.2.1.1 Why Conduct a Comprehensive Forensic On-Scene Investigation of Tire Track Evidence? 307

12.2.2 On-Scene Considerations 308

12.2.2.1 Management 309

12.2.2.2 Archiving 309

12.2.2.3 On-Scene Information 310

12.2.3 Impressions Other than Dirt 313

References 313

Workshop 5: Pattern Evidence 313

W 5.1 2D and 3D Footwear Impressions 313

W 5.1.1 Exercise 1: Casting Footprint and Tire Track Impressions Using Dental Stone 313

W 5.2 Locating Dry (Dust) Residue Prints 315

W 5.2.1 Exercise 2a: Finding Dry and Wet Residue Prints Indoors 316

W 5.2.2 Exercise 2b: Finding Dust Prints Outdoors 317

W 5.3 Lifting Wet and Dry Residue Dust Prints 317

W 5.3.1 Dry Residue Prints 317

W 5.3.2 Wet Residue Prints 319

W 5.4 Tire Impression Evidence 321

W 5.4.1 Recording Known Tire Impressions 321

W 5.4.2 Determining Wheelbase from Tire Impressions 322

W 5.5 Questions 325

Part Ⅳ THE BIOLOGICAL CRIME SCENE 329

13 The Biological Crime Scene: It's Not Just about DNA 329

13.1 Introduction 329

13.1.1 Categories of Biological Evidence 330

13.1.2 Searching for Biological Evidence 331

13.2 Locating Biological Evidence at the Scene 333

13.3 Commonly Occurring Biological Evidence 334

13.3.1 Blood 334

13.3.1.1 On-Scene Testing for Blood 334

13.3.1.2 The Unaided Human Eye 335

13.3.1.3 The Aided Human Eye: ALSs 335

13.3.1.4 IR Cameras: Combining Searching and Photography 336

13.3.1.5 Chemical Presumptive Testing 338

13.3.1.6 Lateral Flow Immunochromatography 341

13.3.1.7 Collecting and Packaging Blood Evidence 342

13.3.2 Semen 343

13.3.2.1 Performing the AP Test on Fresh Semen Stains 345

13.3.2.2 Quality Assurance and Control Testing 345

13.3.2.3 Establishing a Rationale for Searching for Semen 347

13.3.2.4 Collecting and Packaging Semen Evidence 350

13.3.3 Saliva 350

13.3.3.1 Collecting and Packaging Saliva Evidence 353

13.3.4 Urine 353

13.3.4.1 Collecting and Packaging Urine Evidence 354

13.3.5 Feces 355

13.3.5.1 Collecting and Packaging Feces Evidence 355

13.3.6 Vomit 355

13.3.6.1 Collecting and Packaging Vomit Evidence 355

13.3.7 Hair 356

13.3.7.1 Collecting and Packaging Hair Evidence 356

13.3.8 Fingerprint/Skin Residue 356

13.3.8.1 Collecting and Packaging Skin Residue 357

13.3.9 Sloughed-Off Cells 358

13.3.9.1 Collecting and Packaging Sloughed-Off Cell Evidence 358

13.4 Not-as-Common Biological Evidence 358

13.4.1 Bacteria/Spores/Viruses 358

13.4.2 Plant Material 359

13.5 Condom Evidence 359

13.5.1 Collecting and Packaging Condom Evidence 360

13.6 Quality Assurance at the Scene 361

References 361

Workshop 6: Biological Fluids at the Scene--Blood 363

W 6.1 Introduction: Identifying Blood at the Scene 363

W 6.2 Visual Examination 363

W 6.2.1 Exercise 1: Using the ALS to Locate Blood 363

W 6.3 Chemical Testing 364

W 6.3.1 Exercise 2: Presumptive Identification of Blood at the Scene 364

W 6.3.2 Exercise 3: Finding "Invisible" Bloodstains at the Scene: BlueStarTM 366

W 6.4 Immunological Testing: Identifying Human Blood at the Scene 367

W 6.4.1 Exercise 4: Identifying Human Blood 367

W 6.5 Nonblood Evidence at the Scene: Detecting Sugars Using HemaStixTM Strips 367

W 6.5.1 HemaStixTM Strips 367

W 6.5.2 Sugar-Containing Stains 367

References 368

Workshop 7: Drying Time of Blood 368

W 7.1 Introduction 368

W 7.2 Exercise 1: Drying Time of Blood Droplets 368

W 7.2.1 Procedure 368

W 7.3 Exercise 2: Drying Time of a Blood Pool 369

W 7.3.1 Procedure 369

Workshop 8: Locating Semen and Saliva at the Scene 369

W 8.1 Introduction 369

W 8.2 Exercise 1: Using the ALS to Find Semen at Crime Scenes 369

W 8.3 Exercise 2: Using the ALS to Find Saliva at Crime Scenes 370

W 8.4 Questions 371

14 Introduction to Bloodstain Pattern Analysis: The Basics 373

14.1 Introduction 373

14.2 Historical Perspectives: BPA in the United States 374

14.3 Scientific Basis of BPA 376

14.3.1 Biochemistry 378

14.3.2 Physics 379

14.3.2.1 Surface Tension 379

14.3.2.2 Fluid Mechanics (Dynamics) 379

14.3.2.3 Trajectory Analysis (Ballistics) 379

14.3.2.4 Gravitation (Gravity) 380

14.3.2.5 Terminal Velocity 380

14.3.2.6 Centripetal Force 381

14.4 Fundamental Principles of BPA 381

14.4.1 Blood Droplets and Surface Tension: Shape of a Falling Droplet 381

14.4.2 Defining the Direction of Blood Travel 382

14.4.2.1 Shape of Blood Droplets after Striking Surfaces 382

14.4.2.2 Dynamics of Blood-Striking-Angled Surfaces 382

14.4.2.3 Blood or Drip Trails 382

14.4.2.4 Shape and Size of Bloodstains 385

14.4.2.5 Perimeter Stain: Ghosting or Skeletonization 387

14.4.2.6 Calculating the Angle of Impact 387

14.4.2.7 Determining the Origin of an Impact 389

14.5 ArchivingBloodstain Patterns 394

14.6 Bloodstain Artifacts: Selected Examples 394

14.6.1 Insect Activity 396

14.6.1.1 Flies 396

14.6.1.2 Cockroaches 396

14.6.2 On-Scene Activity 396

14.6.3 Fabrics: Differential Absorption 397

14.7 Becoming a BPA Analyst 397

14.7.1 SWGSTAIN-Recommended Guidelines for Training 399

14.7.2 BPA Certification 399

14.8 Quality Assurance Guidelines for BPA 404

References 404

Workshop 9: BPA--The Basics 406

W 9.1 Introduction: Patterns in Blood 406

W 9.2 Falling Blood Droplets 406

W 9.2.1 Exercise 1: Vertically Dropping Blood 406

W 9.3 Exercise 2: Angularity of Blood 408

W 9.3.1 Procedure 408

W 9.4 Exercise 3: Blood Trails 408

W 9.4.1 Procedure 409

W 9.5 Exercise 4: Blood Dripping from Objects 409

W 9.5.1 Procedure 409

W 9.6 Exercise 5: Bloody Footprints 409

W 9.6.1 Procedure 409

W 9.7 Exercise 6: Other Patterns: Swipes, Cast Off, Dragging (Hair), and Crawling 410

W 9.7.1 Swipes and Wipes 410

W 9.7.2 Exercise 7: Cast-Off Pattern 410

W 9.7.3 Exercise 8: Dragging (Hair) 411

W 9.7.4 Exercise 9: Crawling through Blood 411

Workshop 10: Bloodstain Patterns--Impact Spatter and Area ot Origin 411

W 10.1 Introduction: Area of Origin of Impact Spatter 411

W 10.1.1 Exercise 1: The StringMethod--Determining Area of Impact Manually 411

W 10.1.2 Exercise 2: The String Method--Using the Laser to Determine Area of Impact 412

W 10.2 Exercise 3: Multiple Blows--2D Area of Convergence 412

W 10.3 Questions 413

15 Mass Fatality Events, Bioweapons, and Microbial Forensics 415

15.1 Mass Fatality Events: An Introduction 415

15.1.1 Defining Mass Fatality Events 415

15.1.2 The Anatomy of Mass Fatality Events 416

15.1.2.1 Loss of Life and Structure 416

15.1.2.2 The Human Consequences of Mass Fatality Events 417

15.1.3 Identifying the Dead in Mass Fatality Events 418

15.1.3.1 The Ingredients Necessary for Identification 419

15.2 Introduction to Bioweapons and Microbial Forensics 421

15.3 Microbial Forensics 423

15.3.1 Bioterrorism Terminology 424

15.3.2 Bioweapons 424

15.3.2.1 Bacterial Pathogens 425

15.3.2.2 Viral Pathogens 425

15.3.2.3 Other Bioweapon Categories 428

15.3.3 The Bioscene 433

15.3.3.1 Powder or Suspicious Envelopes/Packages at the Scene 433

15.4 Collecting Bioagents at the Scene 438

15.5 Protecting Investigators Performing Environmental Sampling 440

15.5.1 Air-Purifying Respirators 440

15.5.2 Disposable Protective Clothing: Integral Hood and Booties 440

15.6 Mass Fatality Internet Resources 443

References 443

16 Forensic Entomology: Bugs and the Postmortem Interval 445

16.1 Forensic Entomology: Introduction 445

16.2 What Happens after Death 448

16.3 PMI and Life Cycles 448

16.4 Equipment/Reagents Required for Collecting Entomological Evidence 452

16.5 What to Do at the Scene 452

16.6 Arson and Entomological Survival 453

References 455

Part Ⅴ MICROSCENES AND TRACE EVIDENCE 459

17 Microscenes: Hair and Fibers 459

17.1 Introduction 459

17.2 Hair and Fibers as Evidence 459

17.2.1 DNA in Hair 461

17.2.1.1 The Growth Cycle of Hair 461

17.2.1.2 DNA and the Structural Parts of the Hair 462

17.3 Transfer and Persistence of Hair 463

17.3.1 Transfer of Hair at the Scene 463

17.3.2 Persistence of Hair 464

17.4 Collecting and Preserving Hair at the Scene 465

17.4.1 Documentation 465

17.4.1.1 Create a Case File for the Specific Case 465

17.4.1.2 Record Important Case-Specific Information 465

17.4.1.3 Contamination and Loss 465

17.5 Trace Evidence Collection and Preservation Techniques 466

17.5.1 Record Keeping 466

17.5.2 Collection Techniques 466

17.5.2.1 Picking (Hunt and Peck) 467

17.5.2.2 Tape Lifting 467

17.5.2.3 Scraping 467

17.5.2.4 Vacuuming 468

17.5.2.5 Combing 468

17.5.2.6 Clipping and Scraping Fingernails 468

17.6 Evidence Security 469

References 469

Workshop 11: Every Touch Leaves a Trace: Hairs and Fibers 470

W 11.1 Introduction 470

W 11.1.1 Considerations 470

W 11.2 Finding Trace Evidence: Locard Elements 471

W 11.2.1 Picking (Hunt and Peck) 471

W 11.2.2 Tape Lifting 471

W 11.2.3 Vacuuming 472

W 11.2.4 Combing 473

W 11.2.5 Scraping 473

W 11.2.6 Clipping 473

W 11.3 Exercise 2: The Locard Exchange Principle 473

W 11.3.1 Procedure 474

W 11.4 Questions 474

18 Glass: A Multitasking Class of Evidence 475

18.1 Introduction 475

18.1.1 What Is Glass? 475

18.2 Glass as Evidence 476

18.2.1 Direction of Force 478

18.2.1.1 Bullet through a Window 480

18.2.2 When the Radial Edge Fails 482

18.2.3 Direction through a Windshield 482

18.2.3.1 Sequencing Bullet Shots in Plate Glass 483

18.3 Collecting, Packaging, and Preserving Glass Evidence 484

References 486

Workshop 12: Glass as Evidence 486

W 12.1 Introduction: Glass at the Scene 486

W 12.2 Point of Impact 486

W 12.3 Exercise 1: Direction of Force 487

W 12.4 Distribution of Glass Shards 487

W 12.4.1 Exercise 2 488

W 12.5 Questions 488

19 Soil and Paint as Evidence 489

19.1 Soil: An Introduction 489

19.2 The Forensic Premise: Location Diversity of Soil 489

19.2.1 Can Science Differentiate Soil Sufficiently for Forensic Investigations? 490

19.2.2 Do Soil Samples Differ from Location to Location? 490

19.2.3 Is There a Statistical Standard for Soil Matches? 490

19.3 Forensic Value of Soil 491

19.3.1 Soil Taphnomy 491

19.3.2 Associative Evidence: Similarities in Soil Composition 491

19.3.3 Exculpatory Evidence: Dissimilarities in Soil Composition 491

19.3.4 Sequence of Deposition: Layering of Soil 491

19.4 Collecting and Preserving Soil 492

19.4.1 Logic 492

19.4.2 Packaging Soil Evidence 492

19.4.3 Soil from a Cast 492

19.4.4 Exemplar Soil Samples 492

19.4.5 Samples from Vehicles 493

19.5 Paint: An Introduction 494

19.5.1 What Is Paint? 494

19.5.2 Forensic Value of Paint Evidence 495

19.5.2.1 Hit-and-Run Cases 496

19.5.2.2 Burglaries 497

19.5.3 Collecting Paint Evidence 498

19.5.3.1 Scene Samples 498

19.5.3.2 Exemplar or Known Samples 499

References 500

Part Ⅵ BANG! IT'S A SHOOTING INCIDENT SCENE 505

20 Introducing Shooting Scene Investigations 505

20.1 Introduction 505

20.2 On-Scene Considerations and Activity 505

20.2.1 Fragile Evidence 507

20.2.1.1 Gunshot Residue 507

20.2.1.2 Cartridge Cases 507

20.2.1.3 The Usual Fragile Evidence 507

20.2.1.4 Bullets 508

20.2.1.5 Bullet/Projectile Marks and Holes 508

20.3 Basic Facts and Definitions 508

20.3.1 Ammunition 509

20.3.1.1 Small Arms Ammunition 509

20.3.1.2 Shotgun Ammunition 510

20.3.2 Primer Compounds and Their Composition 510

20.3.2.1 Lead-Based Primers 511

20.3.2.2 Lead-Free and Nontoxic Primers 511

20.4 Forensic Ballistics 511

20.4.1 Internal (Interior) Ballistics 511

20.4.2 External Ballistics 511

20.4.3 Terminal Ballistics 511

20.5 Bullets--The Locard Exchange Principle in Action 512

20.5.1 Identifying Bullet Strikes 513

20.5.2 Chemical Analysis of Bullet Holes and Other Defects 513

20.5.3 Bullet Wipe 514

20.5.4 Trace Evidence 514

20.5.5 Testing for Lead 515

20.5.6 Testing for Copper 516

20.5.7 Testing for Nickel 517

20.6 Bullet Holes and Caliber 518

20.7 Trace Evidence and Bullet Holes 519

20.7.1 Blood from Bullets and Bullet Holes 520

20.8 Bullet Flight Paths 520

20.8.1 Intermediate Targets 521

20.8.2 Fatal Bullets 521

20.8.3 Number of Weapons Fired 521

20.8.4 Shooter Position 521

20.8.5 Bullet Flight Path Angular Components 522

20.8.6 Bullet Flight Paths into Fixed Objects 522

20.8.7 Trajectory Rods 522

20.8.8 Angular Components of the Bullet Flight Path 523

20.8.8.1 Vertical Component 523

20.8.8.2 Azimuth or Horizontal Angular Component 524

20.8.8.3 Bullet Flight Paths through Unfixed Objects 525

20.9 Ricochet 527

20.9.1 Tendencies to Ricochet 529

20.9.1.1 Nature of the Bullet 529

20.9.1.2 Shape of the Bullet 529

20.9.1.3 Response of the Surface 529

20.9.1.4 Velocity 529

20.9.2 Surface Characteristics and Ricochet Angles 529

20.9.2.1 Soft or Yielding Surfaces 529

20.9.2.2 Hard or Unyielding Surfaces 531

20.9.2.3 Direction 532

20.9.2.4 Effects of Ricochet 533

20.9.2.5 Deflections 533

20.9.2.6 Why Ricochets Are Important 533

20.10 Packaging/Preserving Firearms Evidence 533

20.10.1 Firearms 534

20.10.2 Bullets 534

20.10.3 Cartridge Cases 535

20.10.4 Ammunition 535

20.10.5 Powder and Shot Patterns 535

References 536

21 Vehicles as Shooting Incident Crime Scenes 537

21.1 Introduction 537

21.2 Two Scenes in One 537

21.2.1 Outside the Vehicle 538

21.2.2 Inside the Vehicle 539

21.2.3 Vehicle Checklist 539

21.3 Bullets and Vehicles 540

21.3.1 Issues in the Determination of Bullet Paths 540

21.3.1.1 Vehicle Composition 540

21.3.1.2 Vehicles in Motion 541

21.3.2 On-Scene Activity 541

21.3.2.1 Positioning the Vehicle 541

21.3.3 Post-On-Scene Activity 543

21.3.3.1 Measuring the Vehicle 543

21.4 Perforating Strikes to Vehicles 545

21.5 Penetrating (Nonexiting) Strikes to Vehicles 546

References 547

Part Ⅶ MISCELLANEOUS CONSIDERATIONS AND SPECIALIZED SCENES 551

22 Fire Scenes: A Scientific Method Investigation 551

22.1 Introduction 551

22.2 The Scientific Method in Fire Investigations 551

22.3 Essential Fire Science 552

22.3.1 Scientific Complexities of a Fire 553

22.3.1.1 Combustion Products 553

22.3.1.2 Heat Transfer or Heat Flux or Energy Flow 554

22.3.1.3 Fuel Load 554

22.3.1.4 Heat Release Rate 554

22.3.1.5 Properties of Flames 555

22.3.1.6 Ignition 555

22.3.1.7 Fire Effects and Fire Patterns 556

22.4 First Responder 556

22.5 The Fire Scene Investigation 556

22.5.1 Archiving the Fire Scene 561

22.5.2 Evidence at Fire Scenes 562

22.5.3 Collecting Evidence 563

22.5.3.1 Liquid Accelerants 564

22.5.3.2 Liquid Evidence Absorbed by Solid Materials 564

22.5.3.3 Solid Samples 564

22.6 Tools, Equipment, and PPE 564

22.6.1 Personal Protective Equipment 564

22.6.2 Tools and Equipment 564

22.7 Fire Resources and Contacts 565

References 565

23 Quality at the Crime Scene 567

23.1 Introduction 567

23.2 A Comprehensive Quality Program for Crime Scene Investigative Units 567

23.2.1 Goals and Objectives 567

23.2.2 Organization and Management 567

23.2.3 Personnel 567

23.2.4 Facilities 568

23.2.5 Evidence Control 568

23.2.6 Validation 568

23.2.7 Analytical Procedures 568

23.2.8 Equipment Calibration and Maintenance 569

23.2.9 Reports 570

23.2.10 Review 570

23.2.11 Proficiency Testing 570

23.2.12 Corrective Action 571

23.2.13 Audits 571

23.2.14 Safety 572

23.2.15 Outsourcing 572

23.2.16 Written Records 572

23.2.17 Organization and Management 572

23.2.17.1 Management Stall 572

23.2.17.2 Personnel 573

23.3 Defining Quality at the Scene 573

23.3.1 Quality Control of Testing Reagents 574

23.3.1.1 Standard Operating Procedure for Blood Testing Reagents 574

23.3.2 Standard Operating Procedures 575

23.3.2.1 Performing the AP Test on Fresh Semen Stains 575

References 576

24 Collection and Preservation of Evidence 577

24.1 Introduction 577

24.2 Rules of Thumb for Packaging Evidence 577

24.3 List of EvidentiaryCategories 578

25 Scientific and Technical Working Groups 589

25.1 Introduction 589

References 590

Glossary 591

Index 599