Guide for the Detection of Footwear and Tire Impressions in the Laboratory
1.1 This Guide provides procedures for the detection of footwear and tire impressions in the laboratory.
1.2 The particular procedures and methods employed in a given case will depend on the nature and quality of the evidence.
1.3 This Guide may not cover all aspects of unusual or uncommon conditions.
1.4 This Guide does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this Guide to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.
1.5 This Guide is not intended as a substitute for training in the detection of forensic footwear and tire track evidence. Completion of a training program and experience in these skills are essential to understanding and applying the principles outlined in this Guide.
3.1 The procedures outlined here are grounded in the generally accepted body of knowledge and experience for the detection of footwear and tire impression evidence. By following these procedures, a forensic footwear and tire examiner can detect both patent and latent impressions.
3.2 Footwear and tire tread impressions are detected in the laboratory for future documentation, collection, and examination.
4.1 Footwear and tire evidence may have inherent limitations that can interfere with the procedures in this Guide. Limitations, when known, should be noted and recorded.
4.2 Limitations can be due to substrate features, quality of original impressions, and method of collection.
5. Equipment and Requirements
5.1 Electrostatic lifting device
5.2 Electrostatic detection device
5.3 Light sources of sufficient type and intensity to allow for detection of impression evidence
Note: Light sources may include natural light, incandescent light, fiber optic, fluorescent light, or forensic light sources of varying wavelengths.
5.4 Photographic equipment
5.5 Materials for physical and chemical enhancement
5.6 Digital imaging equipment and software
The following procedures may be used, as appropriate, depending on the composition of the impression evidence and the substrate material. The order of the following detection methods may vary.