Submission FAQ
Footwear and Tire (Impression Evidence)



Will you examine Footwear or Tire Impressions without having
known shoes or known tires for comparison?

A: Yes, footwear and tire impressions can also be compared against laboratory references to possibly determine a manufacturer or model information for shoes or tires that may have produced the impressions.


What evidence should be submitted for footwear
comparison case?

A: The ideal submission would contain the subject’s shoes, properly taken photographs at the crime scene and any secondary recovery of those impressions.  Properly photographed impressions should be taken using a leveled tripod, with a scale at the same depth as the impression (if 3 dimensional), utilizing different light angles, focusing on the impression and having the impression fill the frame of the camera (no wide-angle lenses).  The scale should include any identifying markers: i.e. 1, 2, 3, A, B, C. Having the identifying markers visible on the scale allows the analysts to correspond the photographs to any secondary recovery method with those same markings.


What evidence should be submitted for a tire comparison case?

A: The ideal tire comparison submission is similar to a footwear comparison with a few additional details.  If a tire impression is long (over 24 inches), a tape measure should be placed along one side of the impression. The tape measure is not utilized as a scale but is used by the analyst to properly overlap the photographs into a complete tire impression. An additional scale with identifying markers should be placed at the same depth as the impression.  All of the same procedures of documenting, processing and secondary recovery apply to tire impressions as well.


Should I submit the entire vehicle for a tire impression case?

A: The entire vehicle can be submitted for comparison and is the preferred standard for comparison. Since this may not always be possible, submitting the tires on the rims removed from the vehicle is the next best option. If physical tires are not able to be collected, standards may be utilized. There are many different ways of collecting tire standards however, using a black ink on a transparent medium is the most useful.  All the tire information should be documented on the standards: brand, model, size, DOT number, tire location on the vehicle and direction of travel.  Photographing a tire limits the comparison but may be helpful in eliminating a tire.


What are the most commonly seen secondary recovery methods?

A: They are casts, lifts and collection and submission of the actual item containing the impression.  Dental stone casts are very useful to analysts.  If a scale is not properly placed in a photograph, the physical size of the impression may be distorted.  A cast is an accurate way to compare physical size in three dimensional impressions.  Casts may also contain randomly acquired characteristics that may not be captured in photographs.


Is casting required for all 3D impressions?

A: Casts are not required to be submitted with all 3d imps, but a secondary recovery method (beyond photo) will give the best opportunity for a more comprehensive examination and can sometimes lead to a more definitive conclusion. Lifting or casting can eliminate some photographic phenomena.


What are footwear lifts and why are footwear lifts important?

A: Lifts can be an adhesive tape lift, a gelatin lift or an electrostatic lift.  Lifts are an accurate way of comparing physical size in a two-dimensional impression.  Black gelatin lifts often capture the highest level of detail in an impression even when processed with black fingerprint powder. Any type of lift aids an examiner with physical size and details that may not be captured in photography.


Should the actual item be submitted?

A: Collecting the physical item that contains the impression may not always be practical but an attempt, if possible, should be made. Evidence that is collected for impression examinations may include flooring, (tile, carpet, linoleum), papers, glass and clothing. Physical items that are submitted may be chemically or physically processed in the Footwear and Tire Section.


I don't see any footwear or tire impressions, should I still
submit the evidence?

A: If a victim is kicked, stepped on or run over by a vehicle, impressions are often developed on the inside of clothing with no visible impressions of the outside.  Other evidence where impressions may be developed when not visible are: on papers (may be chemically processed or lifted if it is an indented impression) and brake pedal covers.


Can shoe size be determined from footwear impressions?

A: Generally, no, unless there is a size indicator in the impression.  A range of manufactured shoe sizes can share the same outsole size.  So, for instance, a manufactured size of 9, 9.5, 10 and 10.5 can all have the same outsole size, but utilize different sized uppers (upper= the part of the shoe that you place your foot into).


Can the direction of travel be determined through examination
of a tire impression?

A: In most circumstances this information is not able to be determined through the examination process.


Will the same level of conclusion be reached if questioned
impressions are compared to shoes/tires versus standards
taken form shoes/tires?

A: The conclusion may be the same but a more complete examination and comparison can be made with shoes/tires as opposed to standards. There are times where a comparison with shoes/tires will result in a more conclusive comparison.


Should I submit all Crime Scene Photographs taken?

A: When submitting photographs on a CD/DVD, analysts will use examination quality photographs first and will not examine overall photographs unless all impressions have been eliminated from the submitted standards or no examination quality photographs were taken.  General crime scene and overall photographs are useful in recreating a crime scene or showing placement but often do not contain the level of detail needed for a proper comparison.


Is there a limited number of pieces of evidence that can be
submitted for a Footwear and Tire Section case?

A: No.  But in a situation where you are unsure of what should be submitted, please contact the Footwear and Tire Section supervisor to advise.A: No.  But in a situation where you are unsure of what should be submitted, please contact the Footwear and Tire Section supervisor to advise.