Forensic Characteristics of Soil Soil The Forensic Definition

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Forensic Characteristics of Soil

Forensic Characteristics of Soil

Soil: The Forensic Definition • Any disintegrated surface material, natural and/or artificial, that lies

Soil: The Forensic Definition • Any disintegrated surface material, natural and/or artificial, that lies on or near the earth’s surface • E. g. naturally occurring rocks, minerals, vegetation, animal matter, glass, paint chips, asphalt, brick fragments and cinders

Comparative Analysis • Link to geographical location of a crime • Soil evidence compared

Comparative Analysis • Link to geographical location of a crime • Soil evidence compared to reference samples collected from crime scene • Color (1, 100 distinguishable soil colors -2008) • Texture

Mineral • Naturally occurring crystalline solid

Mineral • Naturally occurring crystalline solid

Rock • Combination of minerals • Types Igneous Metamorphic Sedimentary

Rock • Combination of minerals • Types Igneous Metamorphic Sedimentary

Building Materials • Brick, Plaster, Concrete Blocks combinations of rocks and minerals • Evidence

Building Materials • Brick, Plaster, Concrete Blocks combinations of rocks and minerals • Evidence in Breaking & Entering Case

Analysis of Soil • Density-gradient Tube • A glass tube filled from bottom to

Analysis of Soil • Density-gradient Tube • A glass tube filled from bottom to top with liquids of successively lighter densities • used to determine the density distribution of soil • See Text: Criminalistics, p. 113 Fig 4 -22

Forensic Value of Soil • Typically provides only Class Characteristics

Forensic Value of Soil • Typically provides only Class Characteristics

Collection and Preservation of Soil Evidence • Establish variation in soil at crime scene

Collection and Preservation of Soil Evidence • Establish variation in soil at crime scene by collecting intervals within 100 -yd radius • Collect samples at alibi locations • 1 Tablespoon of top layer is appropriate • Individually packaged and labeled • Do not remove from an object such as a shoe or garment • Do not break up lumps – layering effect may be helpful