8127/frame/fm

 
Figure 6.1
 
The burglar.
Every criminalist yearns for evidence that yields a
wealth of information with little analysis. Such appears to be the case with a
photograph ascribed to either Edmund Locard or Alphonse Bertillon. Intricate
details can be seen for items such as the buttons on the vest and the weapon in
one hand. The missing little finger on the other hand should also provide a useful
clue to the identity of the phantom. Alas, Duayne Dillon (1998) reveals that this
evidence is too good to be true; he documents the appearance of this photograph
in at least five books, each with differing descriptions of its provenance. According
to these various accounts, an apparent burglar either fell/stumbled/leaped into
clay/mud/sand/dust. The resulting impression was cast in some unknown
medium. This hoax deserved some investigative work of its own, with the results
presented at a “Last Word Society” meeting at an AAFS meeting.
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113
 
Classification, Identification, 
and Individualization — 
 
Inference of Source
A.
The Relationship of Evidence to Source ............................................. 114
1.
Principle, Process, or Objective .................................................... 115
2.
The Question of Source ................................................................ 116
B.
Classification — Categorization with Like Items............................... 116
1.
Class Characteristics...................................................................... 117
a.
Class Characteristics Result from a Controlled 
Generation Process................................................................. 118
b.
Items with the Same Class Characteristics May Have 
Different Origins .................................................................... 119
c.
When Is Evidence Class Evidence? ....................................... 121
C.
Identification ......................................................................................... 122
D.
Individualization................................................................................... 122
1.
A Conclusion of Common Source............................................... 123
2.
Individuality and Uniqueness....................................................... 123
a.
Existent Objects Are Unique ................................................. 123
b.
The Generation of Individual Characteristics ..................... 124
i. Generation by Nature ................................................... 124
ii. Generation by Man....................................................... 125
iii. Entropy and Disorder................................................... 125
c.
The Scale of Detection Is Determined by the Scale of 
Manufacture ........................................................................... 127
i. Signal vs. Noise ............................................................. 128
3.
Individualizing Characteristics ..................................................... 129
4.
Physical Evidence with Individualizing Potential ....................... 129
5.
The Conceptual Process of Individualization ............................. 130
a.
Analysis of Evidence for Class and Individualizing 
Characteristics ........................................................................ 131
i. Collection and Preservation......................................... 131
ii. Examination .................................................................. 131
6
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114
Principles and Practice of Criminalistics
E.
Inferring a Common or Different Source........................................... 137
1.
Conclusion, Inference, or Opinion of Common Source............ 137
2.
Three Inferences ............................................................................ 138
a.
The Items Originate from Different Sources ....................... 138
b.
The Items May Be Classified, but Cannot Be 
Individualized Due to a Limitation of the Evidence or 
the Test .................................................................................... 139
c.
The Items Share a Unique Common Origin ....................... 139
d.
The Conclusion ...................................................................... 140
F.
Mathematical Approaches to Expressing the Strength of the 
Inference ................................................................................................ 140
1.
The Necessity of Providing an Assessment of the Strength 
of the Inference.............................................................................. 140
2.
Tools for Estimating the Strength of the Inference .................... 141
a.
Frequency Estimates............................................................... 142
b.
Likelihood Ratios ................................................................... 142
i. Likelihood Ratios in Bayes’ Theorem.......................... 144
3.
Classification.................................................................................. 145
a.
Hypothesis Testing vs. Bayes’ Theorem — Which One?..... 147
4.
Individualization ........................................................................... 147
a.
Individualization and Opinion — A Special Case .............. 148
G.
Summary ............................................................................................... 150
References ...................................................................................................... 151
The chemical composition between the two was found to be …