The above photo shows a footwear impression and the outsole from a piece of footwear. (click on photo to in higher resolution). Forensic examiners will examine the above for both “class characteristics” and “individual characteristics” that details that may help solve a crime.

“Class Characteristics” are characteristics that are distinct to a particular model of shoe. The identification of class characteristics in footwear impression will allow examiners to determine the manufacture model and sizing of the footwear that made the impression. Some of the class characteristics are present in the photo above include:

• Concentric rectangular pattern in forefoot section of shoe.
• Arch section split up into 9 sections.
• Heel section split into 4 quarters each with “feature markings”.
• 13 longitudinal flex grooves throughout the length of the shoe.
• 3 transverse flex grooves with the lateral most one which run the full length of the shoe.
• channeling located on the arch section on middle and medial size.
• Nike “swoosh” motif located in the arch section on the lateral side.
• “5.0” feature marking located on the medial side of the heel section.
• “Nike Free” feature marking located in the posterior heel section.
• “BRS 1000” feature marking located that posterior end of the heel section.

From the class characteristics identified above, examiners reference them to known footwear databases and determine manufacture, model and size of the shoe that made the impression. The example above, the details of the shoe in question are:

• Manufacture: “Nike”
• Model of footwear: “Nike Free 5.0 v2”
• Size of shoe us: US 9.5 or US 11 women’s.

“Individual Characteristics” are characteristics that are distinct to a particular shoe. These “individual characteristics” consist of random damage to the outsole that is caused by normal usage of the shoe. Forensic examiners will look for common individual characteristics footwear impression and footwear outsole in order to determine possible relationships between the two.

• In the photo above, the presence of 12 individual characteristics in the footwear impression and on the footwear outsole provides a conclusive link between the two. (i.e The shoe on the right certainly created the impression on the left.)