The origin of evidence

Forensic science is an applied science based on the laws of physics and chemistry. Over time, a set of fundamental concepts has developed that apply specifically to a forensic analysis. Traditionally, five concepts have been articulated: transfer, identification, individualization, association between source and target, and reconstruction. We suggest that an additional sixth concept, the idea that matter must divide before it can be transferred, is necessary to complete the paradigm. Divisible matter is particularly useful in describing physical match evidence. Additionally, we propose a paradigm that logically divides into scientific principles that govern the generation of evidence, and processes that pertain to the recognition, analysis, and interpretation of evidence. The principles of divisible matter and transfer pertain to the generation of evidence before and during the crime event; the processes of identification, classification or individualization, association, and reconstruction describe the practice of forensic science starting with the recognition of an item as evidence.