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Soils, Minerals, Wood, & Other Vegetative Matter. bsapp.com. Soils, Minerals, Wood, and Other Vegetative Matter. Location Link suspect Trace Evidence. bsapp.com. Soil. Any material, both natural and artificial, that lies on or near the Earth's surface
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Soils, Minerals, Wood, and Other Vegetative Matter. • Location • Link suspect • Trace Evidence bsapp.com
Soil • Any material, both natural and artificial, that lies on or near the Earth's surface • Most of this evidence is only useful as support or lead generating bsapp.com
Examination of Soil Throughout the examination of soil an observer must: • Look for trace evidence • Compare the physical and chemical properties of each sample to a control sample bsapp.com
Matching Soil Samples Two samples are considered to be the same if and only if they match on each and every level of the following tests bsapp.com
Dry Samples & Pulverize • Dirt changes shade and color at different moisture levels • Dried dirt may clot bsapp.com
Gross Examination • Color • Texture • Shapes • Foreign Objects bsapp.com
UV-Observations • Note the shape, size, number, and identity (if possible) of any material that fluoresces • Compare Samples bsapp.com
The clothes of this female look normal. Any chemicals? bsapp.com
A UV-Light may also be used to find trace evidence on a body bsapp.com
Microscopic Observation • Color • Texture • Shapes • Foreign Objects bsapp.com
Place a thin layer of dirt on a slide bsapp.com
Place only a small amount of sample on the slide at a time. Be sure the dirt is placed only in the center of the slide so as not to allow it to fall in the microscope. WARNING bsapp.com
Naked Eye bsapp.com
Microscopic x10 bsapp.com
Microscopic x40 (Cotton Fiber) bsapp.com
Final Comparison • Any and all foreign objects found should be investigated separately • If all previous comparisons are similar between two samples they likely originate from the same area • As final comparison density gradient columns may be utilized bsapp.com
Naked Eye bsapp.com
Microscopic x40 (Minerals) bsapp.com
Naked Eye bsapp.com
Microscopic x40(Organic Material) bsapp.com
Density Gradient Tubes • Assemble two identical density columns with varying levels of liquids in them • Drop equal amounts of soil samples (a control and unknown) in the columns • Allow the samples to disperse throughout the columns for comparison • If the two samples are of the same origin, then they will produce nearly identical gradient tubes bsapp.com