Ch 13 Forensic Analysis Of Soil

How should soil evidence be packed ?

- Should be packed in individual containers, such as plastic vials - Each vial should be marked to indicate the location at which the sampling was made.

Gross appearance of soils

-Color and texture are very important characteristics -It is estimated that there are nearly 1,100 distinguishable soil colors -Comparison of color is a logical first step in the forensic comparison of soils

Establish variation by collecting numerous control (Known) samples from ?

-Crime Scene -Surrounding Area -Any Alibi Area

Soil found on a suspect?

-Do not scrape -Collect clothing -Package each item separately -Lumps of soil: Collect intact to preserve possible layering

Collection of soil evidence

-Establish variation by collecting numerous control (Known) samples -Known samples must be representative of the area being examined -Quantity must be equal to at least one to two tablespoons of soil -Soil found on a suspect

Minerals

-Naturally occurring crystalline solids -Can be characterized by physical properties such as color, geometric shape, density and refractive index or birefringence. -More than 2200 minerals are known to exist; however most are so rare that only 20 are usually encountered by the forensic geologist -Soil is easily transferred -Comparative in Nature • Density-Gradient Tube • 6 to 10 Layers -Ultimate value depends on variation at crime scene • Rare minerals or rocks • Artificial debris

To develop an idea of the soil variation within the crime scene area, standard/reference soils should be collected at various intervals within a ________ foot radius of the crime scene

100

Where was Alice body found?

Alabama state line into Georgia

Who went missing on The silent Witness Case?

Alice Redmond by her husband 1983

What is soil ?

Any disintegrated surface material, both natural and artificial, that lies on or near the earth's surface.

How are rock identified?

By characterizing their mineral content and grain size.

How is soil differentiated ?

By the gross appearance

True or False; Matter in a solid or liquid state produces an emission spectrum that is characteristic of its composition.

False

True or False; Most soils have indistinguishable color and texture.

False

What evidence can be found in soil?

Forensically we are concerned with rocks, minerals, vegetation, animal matter, glass, paint chips, asphalt, brick fragments,

What evidence did the police fine in The silent witness case?

Found two colors of soil on the undercarriage of Alice's car - The thickest soil was brown - On top of the brown layer was a reddish soil

High power microscopic examination of soil?

Helps characterize minerals and rocks in earth materials.

Who was the prime suspect in The silent Witness Case?

Mark Miller ( co worker ) - Criminal record for burglary and theft

Who was charged in The silent witness case?

Mark Miller was charged with murder and kidnapping

Who was the break in the silent witness case?

Mark miller sister

Naturally occurring crystals commonly found in soils are _________

Minerals

What was used to look the the substances in the soil?

Polarizing Light Microscope

Low power microscopic examination of soil?

Reveals the presence of plant and animal materials as well as artificial debris.

True or False; Each object collected at the crime scene that contains soil evidence must be individually wrapped in plastic, with the soil intact, and transmitted to the laboratory.

True

True or False; The ultimate value of soils as evidence depends on its variation at the crime scene.

True