Chapter 4.3

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Transcript Chapter 4.3

Characteristics of Soil
Pg. 111-115
 List
the important forensics
properties of soil
 Describe proper collection of
soil evidence

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
1.
2.
prevalence at a crime
scene
transferability between
the scene and the
criminal
gross appearance
a.

b.
c.
d.
color (dried), texture
plant and animal materials
artificial debris
minerals and rocks present
 naturally
occurring crystal,
approx. 2200 but only 40 are
most common
 Rocks are characterized by
mineral content and grain
size


1.
Used to compare soil specimens
This test is useful when used in
combination of other tests
Fill a tube with liquids of different
densities
•
2.
3.
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
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
1.
2.
3.
4.
5.
6.
•
need to keep in lump form