Practical relevance of pattern uniqueness in forensic science

摘要

Uniqueness being unprovable, it has recently been argued that individualization in forensic science is irrelevant and, probability, as applied for DNA profiles, should be applied for all identifications. Critiques against uniqueness have omitted physical matching, a realistic and tangible individualization that supports uniqueness. Describing case examples illustrating pattern matches including physical matching, it is indicated that individualizations are practically relevant for forensic science as they establish facts on a definitive basis providing firm leads benefitting criminal investigation. As a tenet of forensic identification, uniqueness forms a fundamental paradigm relevant for individualization. Evidence on the indeterministic and stochastic causal pathways of characteristics in patterns available in the related fields of science sufficiently supports the proposition of uniqueness. Characteristics involved in physical matching and matching achieved in patterned evidence existing in the state of nature are not events amenable for counting; instead these are ensemble of visible units occupying the entire pattern area stretching the probability of re-occurrence of a verisimilitude pattern into infinity offering epistemic support to uniqueness. Observational methods are as respectable as instrumental or statistical methods since they are capable of generating results that are tangible and obviously valid as in physical matching. Applying the probabilistic interpretation used for DNA profiles to the other patterns would be unbefitting since these two are disparate, the causal pathways of the events, the loci, in the manipulated DNA profiles being determinable. While uniqueness enables individualizations, it does not vouch for eliminating errors. Instead of dismissing uniqueness and individualization, accepting errors as human or system failures and seeking remedial measures would benefit forensic science practice and criminal investigation.