Wear is defined as the erosion of a shoe’s outsole or the loss of tread pattern, and it happens gradually over time with use. After a shoeprint is collected from a crime scene, it is questioned whether an individualization can be made if an exemplar is created after additional use of the shoe. The shoes of ten volunteers at San Jose State University were analyzed over a period of 40-45 days. Wear and Randomly Acquired Characteristics (RACs) were analyzed over time to determine if there were any observable changes or additions to the already present wear. It was hypothesized that initial wear and RACs would persist over time. The present wear retained over time throughout the study. Sixty-five percent of the shoes showed no additional wear or RACs. The remaining 35% showed at most 1 cm of additional loss of tread pattern. Therefore, it is possible for an individualization after 40-45 days between evidence collections. This study was limited by the time allotted. Future studies will need to investigate wear over many months of use.
"The Accumulation of Wear on Footwear Pattern Analysis,"
Themis: Research Journal of Justice Studies and Forensic Science: Vol. 7
, Article 1.