Sociology 2266A/B Study Guide - Quiz Guide: Ninhydrin, Optical Microscope, Electron Microscope
26 Jul 2020
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Circumstantial evidence: more reliable than direct evidence, more objective, accurately distinguish individual from other people, e. g. Damilola taylor: 10 year old stabbed to death on his way to computer club, teenage girl came forward with evidence, not accurate- exposed as a greedy, attention-seeker, limitation of ewt. Associative evidence: ties suspect to crime scene, e. g. fingerprints, footwear marks, hair, blood etc. Types of evidence: physical evidence non-living/inorganic items, e. g. explosives, tool marks etc, biological evidence organic items, e. g. blood, saliva. Hair: dna in follicle (with caution)- individual, assess pigments/shape- ethnicity, hair colour, determine species/breed of pet- secondary transfer, determine if hair was forcibly removed (violent crime, chemical analysis for e. g. illegal drugs (with caution) Fibres and hair: recovery: pick off alien material, tape-lift and retain on acetate sheet, analysis: by microscopies, with uv-vis and ir spectroscopies to characterise pigments. Analysis of glass fragments: colour, density, thickness using microscopy, refractive index measurements, x ray fluorescence (elemental analysis)
