Trace evidence is evidence that is found at a crime scene in small but measurable amounts. Examples of typical trace evidence include hairs, fibers, soils, botanical materials, gunshot residue, explosives residue, and volatile hydrocarbons (arson evidence). The most common instrument used in trace evidence analysis is the compound polarized light microscope. Gunshot residue may be identifed by elemental analysis using atomic absorption or with a scanning electron microscope equipped with an energy dispersive spectroscope. Small amounts of explosives, volitile hydrocarbons, and other chemicals are identified with the use of analytical instruments, such as gas chromatography, mass spectrometry, and infrared spectroscopy. A crime scene is a location where an illegal act took place, and comprises the area from which most of the physical evidence is retrieved by forensic scientists. ... Young Girl Fixing her Hair, by Sophie Gengembre Anderson Hair is a filamentous outgrowth from the skin, found mainly in mammals. ... Fiber or fibre[1] is a class of materials that are continuous filaments or are in discrete elongated pieces, similar to lengths of thread. ... Soil is the material on the surface of a lithosphere subject to weathering, and especially the earthy portion of that material. ... Botany is the scientific study of plant life. ... gunshot residues are emitted from the firarm when the trigger is depressedcausing the projectile to leave the barrel. ... This article is concerned solely with chemical explosives. ... In chemistry, a hydrocarbon is a cleaning solution consisting only of carbon (C) and hydrogen (H). ... Arsonists redirects here. ... A microscope (Greek: micron = small and scopos = aim) is an instrument for viewing objects that are too small to be seen by the naked or unaided eye. ... Low temperature SEM magnification series for a snow crystal. ... Gas-liquid chromatography (GLC), or simply gas chromatography (GC) is a type of chromatography in which the mobile phase is a carrier gas, usually an inert gas such as helium or nitrogen, and the stationary phase is a microscopic layer of liquid on an inert solid support. ... Basic schematic of mass spectrometry Mass spectrometry is an analytical technique used to measure the mass-to-charge ratio of ions. ... IR spectrum of a thin film of liquid ethanol. ...