Known Footwear and Known Impression Standards
This chapter provides the examiner's considerations and treatment of known footwear and provides several methods for producing known impressions. When investigators have seized a suspect's shoes for comparison, both shoes should be submitted to the examiner. Providing only test impressions or photographs will not be sufficient to allow a proper examination. Before conducting an examination, photographs of the shoes and outsoles should be taken to document their general condition and appearance as received. Seized shoes often contain mud, possible randomly acquired characteristics of a temporary nature, or materials that may interfere with or prevent the production of known impressions. Known impressions provide an excellent comparison tool, whether examining two-or three-dimensional impressions in the form of photographs, casts, or lifts. They provide natural size known impressions of the outsole in its impression form. Known impressions should be produced in ways that provide accurate and highly detailed recordings of the shoe outsole.