FSC239Y5 Lecture 5: Fingerprint Examination
Document Summary
Fingerprint examinations ~ dna swabs ~ photography ~ court. Lab submissions: property evidence from divisions, guns and gangs, fis, common items firearms (30%) Lab analysis: fingerprint examinations, range of techniques is dependent upon substrate, sequential, swabs for dna. *goal is to get a photograph of fingerprint: sufficient detail to be compared to another fingerprint. Substrates: porous (tape) or non-porous (metal, plastic) Alternate light source: based on chemical being used, cause chemicals to fluoresce, 532nm (laser green), 450nm (blue), uv, barrier filter used to black specific wavelength of light, different barrier for each light. Fingerprint exam chemicals (chemicals will be permanently preserved on print: chosen for surface: porous or non-porous, chosen for contrast, chosen for fingerprint residue, chosen for photography. Porous products: 1,2-indanedione reacts with amino acids and visualized with laser (532nm, 1,8-diazafluren-9-one (dfo, ninhydrin - primarily with amino acids, ambient light. Fingerprint blood: amado black, acid yellow, leucorystal. Filter narrowband pass filter separate background from print.
