Common Terms
Adhesive lifter − Any variety of adhesive-coated materials or tapes used to lift fingerprints or footwear impressions. Primarily used to lift powdered impressions from non-porous surfaces.
Cast -
- A method of making a mold by first making a three-dimensional model of a shoe or tire and then forming the mold from that model.
- The filling of a three-dimensional footwear or tire track impression with material that takes on and retains the characteristics that were left in that impression by the footwear or tire.
- A method used in the lifting of two-dimensional footwear and/or tire impressions from rough surfaces.
Class characteristic − An intentional or unavoidable characteristic (such as physical shape, physical size, tread design/elements or wear position) that repeats during the manufacturing process and is shared by one or more other shoes or tires.
DOT number − Department of Transportation serial number assigned to every tire sold in the United States; it gives information regarding the manufacturer, size and date of manufacture of the tire.
Electrostatic dust print lifter − A system that applies a high-voltage electrostatic charge on a piece of lifting film, causing dust or residue particles from a print to transfer to the underside of the lifting film.
Elimination (exclusion) − An elimination is established when the class, wear and/or individual characteristics present in the questioned impression do not agree with those in the known shoe/tire.
Elimination impressions − Test impressions taken from the shoes and tires of first responders and other known individuals for the purpose of discerning these impressions from the questioned crime scene impressions.
Identification − The positive association of an impression as having been made by a single shoe, to the exclusion of all others.
Inconclusive − A questioned impression that does not exhibit sufficient quality and/or quantity of information may be deemed inconclusive. This indicates that a meaningful scientific conclusion cannot be reached.
Individual characteristic − Something unique about the footwear or tire tread that is not shared by any other shoe or tire—even those from the same production run. It could result from damage or some temporary alteration, such as a stone caught in the tread.
Latent − A type of print that is not visible to the naked eye.
Lift − To transfer an impression from its original surface for the purpose of recovering it from the crime scene and for providing better contrast.
Negative impression − An impression that results when the contact area of a shoe or tire removes residue (such as dust, paint or some spilled substance) from a surface, leaving behind a “clean” image of the print in the residue.
Outsole − The bottom portion of the shoe that provides durability and traction on a surface. It is the outer sole of the shoe, from the toe to the beginning of the heel, but exclusive of the heel itself. With leather soles the grain side of the leather is almost always used for the bottom face or exposed part. In a looser or broader sense, “bottom” may include insole and/or midsole.
Plastic − A type of print that is three-dimensional.
Positive impression − An impression that results when a shoe or tire deposits material onto a surface.
Stone hold − A characteristic created when a tread captures and holds a loose stone. Stone holds are considered individual characteristics.
Tread − The designed part of the shoe or tire that comes into contact with the ground or road.
Wear characteristics − Changes in the surface of the shoe outsole or tire tread that are observable in the impression and/or known shoe or tire, and that reflect the erosion of the surface of the shoe outsole or tire tread.