Evaluation of Evidence

The evaluation of evidence requires consideration of scientific evidence under two propositions, that of the prosecution and that of the defence, and is often concerned with the evaluation of so-called transfer evidence or trace evidence for identification purposes. Transfer evidence is evidence which is transferred from the criminal to the scene of the crime or vice versa. Such evidence is often in the form of traces of some material, such as DNA, glass or fibres. The consideration of such evidence is best done through the Bayesian paradigm. The current interest in the role of statistics in forensic science is fuelled considerably by the advent of DNA profiling. What follows will be described in the context of a criminal case but can be applied to a civil case in which there would be a plaintiff and a defendant.