From biometric scores to forensic likelihood ratios

Abstract

In this chapter, we describe the issue of the interpretation of forensic evidence from scores computed by a biometric system. This is one of themost important topics into the so-called area of forensic biometrics.We will show the importance of the topic, introducing some of the key concepts of forensic science with respect to the interpretation of results prior to their presentation in court, which is increasingly addressed by the computation of likelihood ratios (LR). We will describe the LR methodology, and will illustrate it with an example of the evaluation of fingerprint evidence in forensic conditions, by means of a fingerprint biometric system.