A Survey of Naming Conventions for Different Minutia Types in Friction Ridge Examination

Latent print examiners (LPEs) consider the type and rarity of the features found within friction ridge impressions when determining the suitability of questioned impressions for comparison and when forming opinions about the source of an impression. During training, minutiae are generally grouped into basic minutiae (ridge endings, bifurcations, and dots) and combined, or compound, minutiae (minutiae comprised of combinations of basic minutiae). However, there are no standardized naming conventions for either group of minutiae, which can lead to ambiguity and confusion when communicating what features were observed and relied upon during examinations. In this study, LPEs were presented with images of 14 different basic and combined minutia types and asked to report the labels they use to describe each. A lack of consistency between LPEs in their use of labels for nearly all minutia types was observed, with consensus figures for the most-used label for each minutia type ranging from 12.1% (divergence) to 99.2% (bifurcation). Many reported labels were used by only a single respondent and other single labels were used by LPEs to describe multiple minutia types. The authors developed three desirable naming criteria (short, descriptive but unambiguous, and popular) and applied these to the survey responses, thereby selecting a single, unambiguous label for each of the 14 minutia types. It is recommended that the LPE community adopt these labels to reduce ambiguity and confusion in the communication of LPE results and opinions.