Criminals must enter and exit a crime scene and therefore it is natural that they would leave traces of their footwear. When properly collected and preserved, shoeprints can provide the type, make, description, approximate size, number of suspects, path through and away from the crime scene, the involvement of evidence and the events that occurred during the crime. Consequently, the importance of footwear impression evidence should not be underestimated. Additionally, our recording of shoeprints took two sessions, spread by a two-week interval. This was to collect samples of the same shoe after natural variation had occurred, as a result of things like stones or gum embedded in the sole of the shoe. This variation may have had important identifying details occluded. The ability to ignore these changes and still successfully identify a match is an important skill of forensic professionals, and therefore is an ability of interest for research.
What did we collect?
We took photographs of participants’ actual shoes as a visual record of the brand, model, approximate size, and sole. Photos were taken of the top of each shoe, the right side, the left side, and the sole of each shoe. Additionally, we recorded the shoeprints from the footwear.
We captured shoeprints using the EZID400 Stainfree Footwear Impression System, EZID402C Shoe Impression Report Cards, and EZID403 Shoe Impression Rejuvenator Ink. We varied the type of shoeprint, i.e. whole shoeprints vs. isolated parts of each shoeprints to simulate varying amount of information left in a latent (e.g. whole foot vs. only the heel) and weight distribution (e.g. a heel print places more weight on the back half of the heel, resulting in a contact with the shoeprint card). We collected a whole print, a heel print (back half of the shoe), and a toe print (front half of the shoe) from each shoe.