Forensic examination of glass and paint: analysis and interpretation

Forensic Examination of Glass and Paint Analysis and Interpretation......Page 4
Contents......Page 6
List of contributors......Page 10
Preface......Page 12
1.1.2 Forensic science and criminalistics......Page 13
1.2 Concepts and the production of physical evidence......Page 14
1.3 Uses of trace evidence......Page 15
1.5.1 Introduction......Page 16
1.5.3 Evidence consisting of contactless transfers of material......Page 17
1.5.6 Pattern evidence from contactless transfers of material......Page 18
1.6 Associations based on physical pattern evidence......Page 19
1.6.4 Fracture and physical matches......Page 20
1.7.1 Comparison of materials using morphological criteria......Page 21
1.7.4 Comparison of materials using refined compositional analyses......Page 22
1.8 The role of trace evidence databases......Page 24
1.9 Complementary nature of trace evidence and DNA typing......Page 25
1.10 Recognition and interpretation of trace evidence......Page 26
1.11.1 Hair evidence......Page 27
1.12 Glass evidence......Page 29
1.13 Paint evidence......Page 31
1.14 Miscellaneous types of trace evidence......Page 32
1.15 Future technology and trace evidence......Page 33
1.16 Summary and conclusions......Page 35
1.17 References......Page 36
2.2 Definition of a glass......Page 38
2.4 Glass-manufacturing process......Page 39
2.4.3 Refining and homogenising......Page 40
2.5.1 Glass blowing......Page 41
2.5.3.1 The float glass process......Page 42
2.5.3.2 The rolled glass process......Page 43
2.5.4.2 Glass wool process......Page 44
2.5.7 Glass-tubing manufacture......Page 45
2.5.10 Pressed glassware......Page 46
2.6.2 Coating......Page 47
2.6.4 Decorating......Page 48
2.7.3 Borate silicate glasses......Page 49
2.7.5 Aluminosilicate glasses......Page 50
2.7.9 Chalcogenide glasses......Page 51
2.8 References......Page 57
3.1 Introduction......Page 58
3.2 Recovery......Page 60
3.3 Surface examination......Page 61
3.4 Surface luminescence......Page 62
3.5 Surface contour......Page 64
3.6 Refractive index measurement......Page 67
3.8 Comparison of glass fragments......Page 73
3.10 References......Page 74
4.1 Introduction......Page 76
4.2 Forensic and analytical implications of the composition of glass......Page 77
4.3 Atomic spectroscopy......Page 80
4.4 X-ray methods......Page 85
4.5 Radiochemical methods......Page 88
4.6 Inorganic mass spectrometry......Page 89
4.7 Conclusions......Page 91
4.8 References......Page 92
5.1 Introduction......Page 95
Example 1......Page 96
Example 2......Page 97
Example 3......Page 98
5.5.2 Probability......Page 99
Denominator......Page 100
Numerator......Page 101
Example 5......Page 102
5.7 Elemental analysis......Page 103
5.9 References......Page 104
6.1 Glass as physical evidence......Page 106
6.3.1 Significance of physical matches......Page 107
6.3.2 Demonstration of continuity of ream or cord......Page 108
6.4 Fractures in flat glass......Page 109
6.4.2 Failure upon tension......Page 110
6.4.2.4 Conchoidal marks......Page 112
6.4.3 Failure by Hertzian fracture......Page 115
6.4.4 Propagation of mechanical waves......Page 116
6.5.1 Fractures in container glass......Page 117
6.5.1.1 Internal pressure......Page 118
6.5.1.3 Impact fracture......Page 119
6.5.3.1 Laminated safety glass......Page 120
6.6 Glass fractures produced by firearms......Page 121
6.6.1 Sequence of gunshots......Page 122
6.8 Glass in fires......Page 123
6.9 Retention and persistence of glass fragments in clothing......Page 125
6.10 Future directions for the physical examination of glass evidence......Page 127
6.11 References......Page 128
7.1 Introduction......Page 131
7.4 Paint systems......Page 132
7.5 Formulating principles......Page 133
7.6 Pigments and extenders......Page 135
7.7 Paint manufacture......Page 137
7.8.1 Basic polymer systems......Page 140
7.8.2 Crosslinking systems......Page 144
7.9 Decorative paints......Page 146
7.10 Automotive and refinishing systems......Page 147
7.11 References......Page 149
8.1 Ways in which colour can be described......Page 150
8.1.1 Colour space and the use of tristimulus values and chromaticity coordinates......Page 152
8.1.2 The CIELAB colour space and colour differences......Page 156
8.1.3 Instrumentation for colour measurement......Page 159
8.2.1 Embedding technique......Page 161
8.2.2 Microtome sectioning......Page 162
8.4 Microspectrophotometry......Page 163
8.5 References......Page 169
9.1 Introduction......Page 171
9.2.1 Modes of pyrolysis......Page 172
9.2.2 Gas chromatography......Page 173
9.2.4 Detection systems......Page 174
9.2.6 Applications......Page 175
9.2.6.1 Architectural paint......Page 177
9.2.6.2 Automotive paint......Page 179
9.2.6.3 Motor vehicle body fillers......Page 181
9.2.6.4 Industrial paints......Page 182
9.3 Pyrolysis mechanisms......Page 183
9.4 Pyrolysis mass spectrometry......Page 184
9.6 Advantages and disadvantages of pyrolysis gas chromatography......Page 185
9.8 References......Page 186
10.2 Infrared spectroscopy......Page 189
10.3.1.1 Infrared source......Page 191
10.3.1.3 Detector......Page 192
10.3.2 FTIR instruments......Page 193
10.3.2.5 Detectors......Page 194
10.3.2.7 The FTIR microscope......Page 196
10.4 Preparation of samples for analysis......Page 198
10.4.1.1 Layer separation......Page 199
10.4.1.2.1 Diamond cell......Page 200
10.4.1.2.2 KBr pellets......Page 201
10.4.2 Infrared reflectance spectra (no microscope accessory)......Page 202
10.4.4.1 Sample preparation for transmission spectra......Page 204
10.4.4.2 Sample preparation for reflectance spectra......Page 205
10.5 Infrared analysis of paint......Page 206
10.5.2 Structural formulae and Infrared spectra of some commonly encountered paint resins and pigments......Page 207
10.5.2.1 Alkyd resins......Page 208
10.5.2.3 Acrylic resin......Page 209
10.5.2.4 Epoxy resins......Page 210
10.5.2.5 Polyurethane resins......Page 211
10.5.2.7 Vinyl resins......Page 212
10.5.2.8 Inorganic pigments......Page 214
10.6 Interpretation of IR spectra of non-automotive (domestic) paints......Page 215
10.6.1 Unknown paint sample #1......Page 217
10.6.3 Unknown paint sample #3......Page 220
10.6.5 Reflective traffic paint......Page 222
10.6.7 Heavily pigmented paint......Page 224
10.6.7.1 Marine antifouling paint......Page 225
10.7 Identification of automotive paints by interpretation of their infrared spectra......Page 226
10.7.1.2 Infrared analysis......Page 227
10.7.2 Characteristic peaks in infrared spectra of automotive paint......Page 228
10.7.2.1 Coding of infrared spectra of a four-layer paint chip from a 1995 Ford vehicle......Page 229
10.7.3.1 A visual database......Page 231
10.7.3.2 Computerised database: automotive paint database and search software – the paint data query (PDQ) system......Page 233
Data entry......Page 234
Data query......Page 236
10.8 Application of infrared spectroscopy in comparison of paint fragments......Page 239
10.9 References......Page 246
Appendix 1: Instrumental conditions......Page 247
11.1.1 Forensic considerations......Page 248
11.1.2 Elemental analysis of paints and coatings......Page 249
11.2 Pigments and extenders......Page 250
11.3 History of scanning electron microscopy/energy dispersive X-ray spectrometry (SEM/EDS)......Page 253
11.4.1 Basic operation of a scanning electron microscope......Page 254
11.4.2 Electron beam–sample interactions......Page 256
11.4.3.1 Backscatter detectors......Page 257
11.5 Theoretical principles of energy dispersive X-ray spectrometry (EDS)......Page 260
11.6.1 Embedding and polishing......Page 263
11.6.2 Unembedded cross-sections......Page 264
11.6.4 Thin peels......Page 265
11.6.6 Coating materials......Page 266
11.7.1 Collection parameters......Page 267
11.7.2 Peak identification......Page 268
11.7.2.2 False peaks......Page 269
11.7.4 Comparison of quantitative results......Page 270
11.7.5 Component identification......Page 272
11.8.1 X-ray fluorescence spectrometry......Page 273
11.8.2 Wavelength dispersive X-ray analysis (WDX)......Page 274
11.9 Discrimination......Page 275
11.12 References......Page 276
12.1 Introduction......Page 278
12.2.1 Wet paint......Page 279
12.2.3 Persistence and secondary transfer......Page 280
12.3 Household paints......Page 281
12.4 Vehicle paint......Page 283
12.5.1 Single layer of paint transferred from suspect vehicle to injured party’s vehicle......Page 286
12.5.2 Single layer of paint transferred from injured party to suspect vehicle......Page 288
12.5.4 Transfer of multilayer manufacturer’s finish from suspect vehicle to injured party......Page 289
12.5.6 Exchange of multilayer manufacturer’s finish......Page 290
12.7 References......Page 291