ABSTRACT
A. Association ............................................................................................ 158 1. Evidence and the Law Revisited ................................................... 158
a. The Lawyer, the Scientist, and Relevance ............................. 158 2. Inferential Reasoning in Science .................................................. 160
a. Science and Inductive Inference ........................................... 160 i. The Alternate Explanation .............................................. 163
ii. Uncertainty ....................................................................... 164 3. Inferential Reasoning in Forensic Science ................................... 165
a. Association and Interpretation — A Divergence of Understanding ........................................................................ 165
b. Inference and Association...................................................... 166 c. Inference and Interpretation ................................................. 168 d. The Source of the Confusion ................................................ 168
4. Definition of Association.............................................................. 169 5. Associating Two Objects through an Inference of Contact ....... 170
a. A Bayesian Framework for Inferential Thinking — Principle or Practice............................................................... 170
b. Hypothesis Testing and Likelihood Ratios ........................... 171 c. The Analyst and the Evidence — Articulating
Hypotheses.............................................................................. 172 d. Absence of Evidence .............................................................. 173
e. Combining Source Determination and Inference of Contact.................................................................................... 175
f. O. J. and Inference — Is the Tube Half Full or Half Empty? .................................................................................... 175
6. Who Makes the Inference?............................................................ 176 B. Reconstruction ...................................................................................... 177
1. The State of the Practice............................................................... 177 a. Definition of Reconstruction ................................................ 178
2. Capabilities of Reconstruction ..................................................... 178 a. Predictive Value of a Simulation........................................... 180 b. Corroboration or Refutation of Statements......................... 180
3. Limitations of Reconstruction...................................................... 181 a. Bias and Expectation.............................................................. 182 b. Overinterpretation ................................................................. 182 c. Reconstruction or Reenactment ........................................... 188
C. Summary ............................................................................................... 188 References ...................................................................................................... 189
1. Evidence and the Law Revisited
As we have seen, much of the research and analytical effort of the criminalistics community is devoted to source determination. The next step of our paradigm,
association
(inferring contact between two objects), bridges the laboratory work product of the scientist and the needs of the law by making a statement about the meaning of the physical evidence in light of the specific case circumstances. A great amount of misunderstanding between scientists themselves, as well as between scientists and lawyers, results from a failure to appreciate this essential role of associating two objects, and the factors involved in the inferential process used to effect the association.
