Analysis of Footwear Impression Evidence

Impressions of footwear are commonly found in crime scenes. The quality and wide variability of these impressions makes their analysis difficult. This research will develop new computational methods to assist the forensic footwear examiner in the U.S. The research involves developing a database of representative footwear print images so that appropriate algorithms can be developed and their error rates can be determined. Algorithms for identifying special features such as wear marks and embedded pebbles will be developed. Matching algorithms to be developed will be for both the tasks of verification, where the goal is to determine whether the footwear evidence is from a particular suspect's shoe, or that of identification, where the goal is to determine the brand of the shoe from a known set of brands. In each case a quantitative measure of the result of matching will be provided. In the identification mode, the tools will allow the narrowing down of possibilities in a database of known prints. Another goal of the project is to assist the U.S. footwear examiner is homicides and assaults where there are no known prints to match. For this purpose a classification tool is to be developed, where the objective is to generate from the evidence a set of characteristics, e.g., gender, size, and brand. The work will be conducted following the guidelines of SWGTREAD and in close consultation with forensic footwear and/or tire tread examiners.