What does the term "contaminated" refer to in relation to footwear or tire imprints?

The term "contaminated" in relation to footwear or tire imprints specifically refers to imprints made by footwear or tires that have come into contact with a substance, which alters or adds to the characteristics of the imprint. This could include residues like mud, dirt, oil, or any other substance that may have been present on the footwear or tires when the imprint was made.

When an imprint is made under these conditions, it often carries additional information that can be pivotal in forensic science. This could include the type of surface the shoe or tire contacted, as well as potential transfer of chemical or biological evidence. Thus, a contaminated imprint can provide greater context for an investigation by linking a particular individual or vehicle to a crime scene or location.

In contrast, imprints made on dry surfaces or those made with a wet substance do not inherently imply contamination; they simply describe the conditions under which the imprint was made. Therefore, the focus on residue highlights the specific nature of contamination in forensic analysis.