Footwear Impression Unit
This type of analysis involves attempting to associate a subject’s shoes to a cast, photograph or lift of a footwear impression left at a crime scene to link the suspect to that scene. The examiner compares the impression left at the scene with the suspect’s shoes to determine if they share any class characteristics, similar tread design, size and/or wear characteristics or accidental characteristics. Class characteristics are those present in multiple items of the same type. Individual/accidental characteristics are those unique to a single item and allow a positive identification to that item.
Investigative lead information regarding the manufacturer, model and size of the footwear can be determined from the design in the impression left at the crime scene. Reference collections and databases are used to develop this type of information.