Digital subtraction techniques applied to analysis of footwear changes with time

Linking a suspect to a scene, has traditionally comprised the majority of footwear examinations. To a lesser extent, effort is directed at linking scenes by determining footwear marks common to them. More recently, changes in the approach to policing have increased the requirement for linking of scenes and intelligence activities. The introduction of advanced computer technology has provided the opportunity for large databases of footwear marks, allowing linking of scenes, and suspects to scenes, over large geographical areas. The paper discusses a computerised system for this purpose by Envisage Systems Ltd