Chapter 13: Soil Evidence

This set of flashcards focuses on key vocabulary and concepts related to forensic soil evidence, outlining definitions and contextual meanings.

Forensic soil evidence

Analysis often key to solving crimes due to soil's unique properties.

Soil analysis

Uses soil sciences, geology, chemistry, mineralogy, and biology.

Soil as evidence

Valuable due to its presence everywhere, it's easily collected and analyzed.

Soil formation

Complicated process influenced by environmental factors.

Distinctive soil characteristics

Physical and chemical traits used to link people or objects to crime scenes.

Dr. Hans Gross

Austrian forensic expert who believed in soil as trace evidence.

Georg Popp

German investigator who used soil evidence to solve a murder in 1904.

PMI estimation

Using microbes in soil to estimate time since death.

Soil composition

Mixture of weathered rock, microorganisms, organic matter, water, and air.

Soil texture

Most soils are mixtures categorized based on sand, silt, and clay percentages.

Soil chemistry

Influences and is influenced by the plant and animal life in the area.

Soil profiles

Layers of soil horizons; unique sequences in geographic areas.

Cadaver Decomposition Island (CDI)

Isolated soil area barren of plant growth due to decomposition.

Soil moisture

Can influence decomposition rates and the formation of adipocere.

Characteristics of sand

Includes formation from weathered rocks and minerals.

Sand size range

Particles 0.05 to 2 mm in diameter.

Mineral composition of sand

Depends on mineral types including quartz, feldspar, and iron.

Continental sand

Results from weathering of continental rock.

Biogenic sand

Composed of remains from marine organisms.

Precipitate sand

Forms from minerals coming out of a water solution.

Sorting of sand

Based on size, color, angularity, and movement degree.

Collecting soil evidence

At least four tablespoons should be collected from various locations.

Disturbed soil profiles

Indicates human alteration, often when gravesites are dug.

Microscopic soil analysis

Provides origin information like sea life or distinctive diatoms.

Macroscopic soil analysis

Includes botanical evidence linking suspects to crime scenes.

Physical soil analysis

Involves examining sorting, soil profile, UV reactions, and more.

Chemical soil analysis

Determines mineral composition and soil's pH value.

Biological soil analysis

Involves DNA analysis for specific microbial sequences.

Ground-penetrating radar

Used to locate buried bodies in forensic investigations.

Thermal imaging

Helps in detecting gravesites by assessing heat signatures.

Soil texture types

Based on particle size, categorized as sand, silt, and clay.

Types of sand

Includes continental, volcanic, skeletal, and precipitate sand.

Locating gravesites

Look for mounded or depressed soil, vegetation changes, and cadaver islands.

Soil and crime-solving

Helps link individuals or objects to specific crime scenes.

X-ray diffraction

A technology improving soil analysis in forensic investigations.

Satellite photography

Enhances ability to locate gravesites through aerial views.

Chemical and biological actions

Drive the formation and characteristics of soil.