1. Characteristics of Soil Pg. 111-115
4.4 Notes
Characteristics of Soil Pg

2. Objectives List the important forensics properties of soil
Describe proper collection of soil evidence

3. Soil
any disintegrated surface material, both natural and artificial, that lies on or near the earth’s surface.
Naturally occurring rocks, minerals, vegetation, animal matter
Manufactured objects

4. prevalence at a crime scene
Critical as evidence
prevalence at a crime scene
transferability between the scene and the criminal

5. Soils differentiated by:
gross appearance
color (dried), texture
plant and animal materials
artificial debris
minerals and rocks present

6. naturally occurring crystal, approx. 2200 but only 40 are most common
Mineral
naturally occurring crystal, approx but only 40 are most common
Rocks are characterized by mineral content and grain size

7. Density Gradient Tube Technique
Used to compare soil specimens
This test is useful when used in combination of other tests
Fill a tube with liquids of different densities
Layer on bottom is most dense, each subsequent layer is of decreasing density
Add soil samples
Particles of same density will be suspended in the match point density

8. Collection and Preservation
Standard/reference soils collected at various intervals within 100 yd radius
Samples collected at the alibi locations
Need 1-2 T of soil for a sample
Specimens packaged in individual containers
Objects with soil are collected
Samples of soil are collected under car fenders and frame
need to keep in lump form

9. In-Class Assignment/Homework