FSCI 1010U Lecture 4: Trace Evidence: Glass, Fibres, and Hairs
11 Feb 2017
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Document Summary
Locard"s exchange principle tells us that: every contact leaves a trace. Primary: direct contact soil from gravesite in shoe treads of killer. Secondary: indirect contact sit in someone else"s car, their dog"s hair is transferred to you. Quite often the evidence that is transferred is small or even microscopic in size, making analysis quite difficult. Should be of no surprise that our microscope is one of the most important tools of the forensic trace analyst. The applications of a microscope and microscopical techniques to the observation, collection, and analysis of micro-evidence that cannot be clearly observed or analyzed without such devices. Generally deals with samples in the milligram (mg) or microgram (mg) Often operates using different forms of energy: visible, ultraviolet, infrared, or electrons. Many types of microscopes available for use in a forensic laboratory for a wide variety of materials, we will only discus a few: Basic scanning electron microscopy (sem) with energy dispersive x-ray spectroscopy (eds)
