NCJ Number
211279
Journal
Journal of Forensic Sciences Volume: 50 Issue: 5 Dated: September 2005 Pages: 1071-1080
Date Published
September 2005
Length
10 pages
Annotation
In an attempt to advance past research which studied the outlines of footprints of persons walking normally to determine whether different people made verifiably distinct footprints, this study reports on two new advances: a rigorous mathematical framework for chance-match probabilities and the substantiation of the previous research.
Abstract
Forensic barefoot morphology comparison examines the shapes of barefoot impressions in order to determine whether a suspect should be included or excluded as the person who made a footprint linked to a crime scene. This study was an enhancement of an earlier pilot study where footprint impressions of 960 Caucasian males were collected using an inkless pad and specially treated paper with a repetition sample of 20. The study used the same methodology for the collection of the data as the pilot. An inkless pad and chemically treated paper were used to collect impressions. However, this study used a larger sample population of 5,755 with a repetition sample size of 134. The improvements and enhancements to the research which included a rigorous mathematical framework for calculating worse case and average chance-match probabilities and repeating the experiment with an expanded population sample size, as well as a bigger repeated sample, lead to a sharpened accuracy with average chance match probabilities for a general population. The results of the study include contributions to both the theoretical framework and the analysis of new experimental data. Figures, tables and references