Soil analysis can link suspects to crime scenes by comparing soil on their clothing or vehicles to the soil at the crime scene. Physical characteristics like plant and animal materials or artificial debris are examined microscopically. Chemical characteristics like pH levels and minerals are also analyzed. To determine if soil samples have a common origin, analysts consider multiple comparable features and how frequently they occur. Proper training in geology is important since there are over 2,200 minerals that can be present in soil.

1. TRACE EVIDENCE SOIL ANALYSIS

2. Soil soil or dried mud adhering to suspect’s clothing or shoes or to an automobile may link a suspect or object to the crime scene when compared to the soil there soil analysis without a crime scene can also be helpful in finding the place where the crime was committed

3. Soil analysis must be made with soil dried under identical lab conditions analysts look for physical characteristics chemical characteristics

4. Soil physical characteristics microscopic examination – reveals presence of plant and animal materials any artificial debris helps characterize minerals and rocks in earth materials

5. Soil physical characteristics color – 1,100 soil colors soil types magnetic particles fluorescence

6. Soil chemical characterisitics pH nitrates, phosphates, potassium carbonates, iron, chloride, copper

7. Soil to determine common origin of soil samples one must consider… number of comparative points frequency of occurrence

8. Soil geology training helpful 2,200 minerals exists, only ~20 are common rocks are combinations of minerals, characterized by mineral content grain size – using sieve set

9. Soil – Mineral Properties color useful but limited many minerals appear in a variety of colors many are white or colorless size simple labels: coarse, medium, fine grains use of sieve set to further describe

10. Soil – Mineral Properties texture describes crystal’s outward appearance generally referred to as the “habit” of a crystal

11. Soil – Mineral Properties texture – habits dendritic – has a plant like shape as in copper

12. Soil – Mineral Properties texture – habits bladed – appears as layers that look like the blades of knives as in actinolite

13. Soil – Mineral Properties texture – habits acicular – forms as pointy, needle-like masses, or radiating as in scolecite

14. Soil – Mineral Properties texture – habits massive – has no definite shape as in limonite

15. Soil – Mineral Properties texture – habits prismatic – looks like many prisms fused together (as in barite) or a uniform cross section (as in beryl)

16. Soil – Mineral Properties texture – habits reniform – looks like a jumble of rounded masses as in hemitite

17. Soil – Mineral Properties luster describes the way light is reflected off of the mineral’s surface type and intensity vary according to mineral surface amount of light absorbed

18. Soil – Mineral Properties luster vitreous glass-like

19. Soil – Mineral Properties luster greasy milky

20. Soil – Mineral Properties luster silky satiny

21. Soil – Mineral Properties luster pearly

22. Soil – Mineral Properties luster metallic

23. Soil – Mineral Properties luster dull or earthy