FSC239Y5 Lecture 8: Footwear and Other Impression Evidence
Document Summary
Transfer of class and individual characteristics from footwear to surface: id of possible suspects, id of witnesses. 2d and 3d impressions (3d cast use for experiments) Presence at scene/participation in crime: context established significance. Measurements changes depending on factors such as: speed, size, surface, type of shoes, slip. Locate footwear evidence: requires deliberate effort oblique lighting electrostatic lifting. Chemical development: partial impressions most often found. Document evidence: scene and examination quality photographs. Recover evidence: electrostatic lifting devices (eslds) Simple premise: opposite charges attract, surfaces positive, dust particles negative. Esld creates a more concentrated charge on lifting medium: greater charge on film attracts dust and dirt from surface, residual, electrostatic lifting devices. Useable on wide range of surfaces, like floors, walls, doors, clothing, carpet and paper. Impressions may not initially be visible to naked eye. Produce known impressions and compare with scene impressions. Not only perpetrator(s)" footwear impressions at scene.
