Soil
and
Forensic Geology
What Is Soil?
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Mixture of organic and inorganic material
May range from 100% inorganic (sand) to
nearly 100% organic (peat)
Inorganic part is minerals
Organic part is decayed plant and animal
material and is sometimes called humus
Forensic Significance of Soil

Soil is class evidence - cannot be
individualized to a particular location
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There is no classification system for soils
Soils can be easily transported
Soils within a few meters horizontally or
vertically differ
Forensic Analysis of Soils

Bulk analysis
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Density gradient
Particle size distribution (sieving)
Inorganic components
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Color (dissolve in water)
Petrography - mineral analysis; Requires a
good deal of skill and practice
Forensic Analysis of Soils

Organic components
 Liquid chromatography
 Oxygen availability
 Bacterial DNA? - Future possibility
Why is soil such a good source of
evidence?
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Large Variations of soil characteristics
Extreme Complexity of its composition
 Minerals
 Oxides
 Organic Matter
 Microorganisms
 Artificial additions (concrete, asphalt, plastics)
 Runoff additions (salt, fertilizers, pesticides)
 Manufactured products: glass, paint, asphalt, brick,
industrial products,
Complex Physical Nature
 Varies due to above compositions
Forensic Geologists

The forensic Geologists examinations
involve the identification of:
 Earth materials
 Comparison of samples to determine
common source
 Studies that aid a criminal
investigations and intelligence studies.
Forensic Geology In
Intelligence Work
Remember the outcrop you saw behind Osama bin Laden
on TV after September 11. What was the location?
A geologist who has done field work in the area would be
able to locate that outcrop, and that actually
happened: Geologist John Shroder was able to identify
the region where bin Laden had been sighted in
Afghanistan in 2001 (see Geotimes, February 2002).
Forensic Geologists of the Past

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Starting in 1887 Sir Arthur Conan Doyle
wrote The Sherlock Holmes series used soil
and residues many times to link individuals to
specific locations.
In 1893, Hans Gross, authored “Handbook
for Examining Magistrates”. In it he
suggested that the dirt on someone's shoes
could tell more about where a person had
last been than many other techniques used
in that time.
The Eva Disch Case
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In October 1904 a dirty handkerchief containing bits of
coal, snuff, and grains of the mineral hornblend was
found at the murder scene of a seamstress named, Eva
Disch.
A suspect was found who used snuff, and worked parttime at both a coal burning gas works and a quarry that
had an abundance of the mineral hornblend.
The suspect also had two layers of dirt in his pant
cuffs. The lower layer matched the soil at the crime
scene and the upper layer, characterized by a particular
type of mica particle, matched the soil found on the
path to the victim's home.
When confronted with the evidence the suspect
confessed. (Murray and Tedrow, 1991, p. 4)
Forensic Geologists
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The microscope is and will remain an important tool.
Qualifications and competence of examiners
is a major problem.
 Should

those qualifications be regionalized?
The future will see:
 Improved training of those who collect and
analyze samples
 Increased automated methods of examination
 Improved research:
 The diversity of soils
 What parts of soil are transferred during
various types of contacts and could their be a
pattern
Forensic Geologists Questions
Interconnected by the following
questions:
1. What is this material?
2. Where did this material come from?
3. Is this material unique to a crime
scene or unique to circumstances
under which a criminal act was
committed?
4. What is the geologic context of a crime
scene?
My Husband Went hunting and never
came home 

A pond with bentonite (clayish mud) in the mountains
of western Colorado proved to be a really great place
to camp for John Dodson.
Physical Properties of Soil
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Soil Texture, Structure,
Compaction
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is the percent of sand, silt and clay
in a soil.
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sand is the coarsest (0.06 - 2 mm)
silt is intermediate (0.002 - 0.06 mm)
clay is the finest (<0.002 mm)
Soil Texture

The texture of a soil is determined by the
percentages of particles like sand, silt, &
clay that it contains.
Physical Properties of Soil
Soil Comparison:
Simple observations using local geologists
 Color of dry sample, (1,100 controls)
 Texture of dry sample
 Composition:
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Mineralogy, mineral: crystalline solid
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+2,200 minerals,
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40 commonly seen
ROCKS COMPOSION VARIES BASED ON MINERAL COMPOSITION
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Mineral content
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Grain size
LP Microscopy, shows animal, plant and artificial remains
and their %s
 Side by side comparison
Minerals:

Minerals are used by various
commercial and industrial companies.
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Brick, shale, plaster, and concrete are all
found in many indoor products, drywall
insulation.
Robbery suspects often have minerals
within clothing fibers.

Why????
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Locard’s Exchange Principle
Locard’s Exchange Principle

The exchange of materials between
two objects that occurs whenever
tow objects come into contact.
Physical Properties of Soil
Organics
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Humus: a mixture of organic material
that binds nutrient mineral ions and
holds water.
Detritivores like Earthworms, termites, and
ants help to breakdown humus.
Humus persists in agricultural soil for
about 20 years.
Humus  CO2 + H2O + nutrient +
minerals
Physical Properties of Soil
(Organisms)
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Bacterial and Protozoan colonies
Plant litter
Fungi
Animal
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Most common insects, arachnids, and
annelids
Materials in varying states of
decomposition
Physical Properties of Soil
Soil Pore Spaces
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Pore spaces: Occupy about 50% of a
soils volume and can be filled with H2O
(soil H2O) or air (soil air).
Soil air is found in larger pores.
Soil H2O is found in smaller pores
(0.05mm).
Physical Properties of Soil
Soil Horizons
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Horizontal layers of
organized soil.
A soil profile is a
vertical section from
surface to parent
material.
Soil Horizon
Basic
Soil Horizon
Basic
Boreal Forest
Soil Horizons
Soil Horizons for Honors??
Soil Collection
Various interval 100 yard radius of the CS.
 Sampling Surface and Subsurface layers
 Approximately 1 tablespoon per sample
 Individual plastic vials
On Suspect
 Both soil and object are wrapped in paper
 Layering effect on vehicles: occurs over time due
to sedimentation
 Collected separately only if jarred loose
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Laboratory Possibilities
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Soil Comparisons
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Soil nutrients, Nitrate
and Phosphorus
Water holding capacity
Texture
pH
Organic Content
Sieve Percent Composition
Undisturbed vs. newly
disturbed soil
Density
Leads to other chapters
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Crime Scene
Impression
 Foot and tire
Anthropology
Botanicals
Inductively coupled plasma
mass spectrometry (ICPMS)
(Ask Mark He can get you one)
Soil Comparison:
•
•
Differences in soils can identify
location of victims, suspects, or the
crime scene.
Or Inconsistencies between them!!
•
Remember the DEA SA Camarena?
Disturbed Soil Comparison:
Old
Undisturbed
Soil
same
consistent
color
Newly
disturbed
Soil
showing
O-Layer:
(Organic)
fresh,
organic
topsoil
layer
Excavations:
Lab: Investigating Soil
Core Sampling
Lab: Finding Your Past
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Objective: Locate evidence of a past
structure that is no longer in
existence.
Hint: Try to remember past homes,
hangouts, relatives homes . Can you
think of a structure
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Change the color of your house?
Relocate a structure?
Lab: Finding Your Past
Lab: Finding Your Past
Lab: Finding Your Past
Charcoal tells us what??

Another Attempted Cremation: Like Hitler, Joseph
and Magda Goebbels were cremated. The bodies of their
six children remained in the bunker. They were found by
Russian soldiers when Berlin fell to the Allies.
Density-Gradient Tube:
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Glass tubes measuring 6 to 10 millimetres in diameter and
25 to 40 centimetres in length are filled with several layers
of two liquids mixed in varying proportions such that each
layer has a different density.
An example is the mixture of tetrabromoethane, which has
a density of 2.96 gmL-1 with ethane, with a density of
0.789 gmL-1.
The soil components then sink to the layers corresponding
to their own density values and the distribution of particles
can be compared between soil specimens.
Sample from
Crime Scene
Courtyard
College
Gardens
Sports
Pitch
Inductively coupled plasma mass
spectrometry (ICP-MS)
The coupling of ICP-MS shows many advantages over other
analysis techniques.
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Benefits of the ICP over other radiation sources include
improvement in excitation and ionization efficiencies and the
reduction or elimination of many of the chemical interferences
found in flames or furnaces.
Mass spectrometry generates a large amount of information,
has high throughput capabilities, high sensitivity and low limits
of detection. ICP-MS is capable of multi-elemental detection
which reduces analysis time and therefore increases sample
throughput. ICP-MS is one of the few analytical techniques that
permits the quantifying of elemental isotopic concentrations
and ratios.
It can achieve very low limits of detection
Inductively coupled plasma mass
spectrometry (ICP-MS)
An analysis of the elemental composition of the soil.
 The plasma is formed by argon gas flowing through a
radiofrequency field where it is kept in a state of
partial ionization, i.e. the gas consists partly of
electrically charged particles. This allows it to reach
very high temperatures of up to approx. 10,000ºC.
 The sample being analyzed is introduced into the
plasma as a fine droplet aerosol. ICP-MS is the
combination of an ICP with a mass spectrometer (MS).
 The ions generated by the ICP are directed into the
MS, which separates the ions according to their massto-charge ratio. Thus, ions of a selected mass-tocharge ratio can be detected and quantified.
Inductively coupled plasma mass
spectrometry (ICP-MS)
Inductively coupled plasma mass
spectrometry (ICP-MS)
Inductively coupled plasma mass
spectrometry (ICP-MS)
Inductively coupled plasma mass
spectrometry (ICP-MS)
Finito’
Website link: Analytical Techniques for the Comparison of Soil Samples
Links:
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www.channel4.co.uk/.../S/science/
images/fracture.gif
http://www.file:///C:/InetTemp/Content.IE
5/QFML2789/256,1,All About Glass
http://www.adtdl.army.mil/cgibin/atdl.dll/fm/19-20/Ch10.htm
Sewage leak do to inadequate
Support
Sherlock Holmes

“…observation shows me that you have
been to the Post Office this morning, but
deduction lets me know that you
dispatched a telegram.”
Sherlock Holmes
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“It is simplicity itself. Observation tells me
that you have a little reddish (soil) mould
adhering to your instep. Just opposite the
post office they have taken up the
pavement and thrown up some earth. (It
is) impossible to go to the post office
without treading that dirt. The earth is a
particular reddish color not found
anywhere else in town – observation – the
rest is deduction.”
Some Interesting? Cases Where
Geological Evidence Has Been
Important
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Florida v. William Kennedy Smith
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South Dakota v. Donald Eugene Moeller
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Colorado v. Walter Osborne
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The Death of a DEA agent – Enrico
Camarena
Florida v. William Kennedy
Smith
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WKS accused of rape of Patricia Bowman
Alleged attack on grass lawn behind Kennedy
estate in W. Palm Beach, Fl
WKS alleged consensual sex on the beach near
estate
Jay Siegel used PLM to compare samples from
clothing of victim to lawn and beach areas
Samples consistent with beach, not lawn
WKS acquitted of rape
South Dakota v. Donald Eugene
Moeller
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Capital murder case of 9-year old Becky
O’Connell on May 8, 1990.
Testimony by soil expert refutes defendant alibi
Victim snatched off street, raped, killed, body
dumped in woods.
Suspicion fell on Defendant because of prior sex
crime involvement.
Found guilty and sentenced to death. Appeal
resulted in reversal owing to admission of
evidence of prior bad acts.
South Dakota v. Donald Eugene
Moeller (cont.)
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SD Supreme Court reversed and reinstated
conviction
State geologist analyzed soil found in wheel wells of
defendant pickup truck. Issue was whether soil
came from crime scene South of Sioux Falls or from
a road North of Sioux Falls where defendant claimed
he was at time of crime
Geologist testified that soil could have come from
crime scene.
Opinion based on:
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Colors and general characteristics
Soil was much lighter or could not have come from other
roads in area
“Sharp, clean” hornblende crystals much more likely to
South Dakota v. Donald Eugene
Moeller (cont)
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Part of appeal called for striking
geologist’s testimony as being too
speculative as to conclusions
At 2nd trial, geologist came into more
evidence from scene and wheel well: dark
green to black gahnite found at scene
and in evidence from truck. This mineral
extremely rare.
South Dakota v. Donald Eugene
Moeller (cont)
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Defense argued that geologist erred in
identifying gahnite only by visual inspection.
Claimed that PLM should have been used (to
confirm that gahnite is isotropic) and that x-ray
diffraction should have been used to confirm.
Appeals court rejected appeal
There was no discussion at trial whether the
finding of both hornblende and gahnite near
Sioux Falls was a rarity or could be due to
processing after mining elsewhere. Bedrock of
Sioux Falls contains neither hornblende nor
gahnite.
Colorado v. Walter Osborne
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Osborne botches kidnapping of Adolph
Coors from his ranch near Morrison and
kills Coors
Ranch is near “Dakota Hogback” which is
made of Dakota sandstone underlain by
gray, green and maroon clay stones,
shales, more sandstone and limestone.
Dirt road near ranch was essentially
eroded, pulverized components of
hogback.
Colorado v. Walter Osborne
(cont)
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During kidnapping, a fight broke out and
Osborne shot Coors. Fled in Osborne’s
yellow Mercury with body. Fled south
onto an unpaved road in next county.
Then went west and climbed. Road made
of muddled dust; pink-feldspar. Dust was
granite, but compared to bedrock was
deficient in iron and magnesium.
As he climbed further, came into Pike’s
Peak granite – very distinctive.
Colorado v. Walter Osborne
(cont)
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At 7200 ft, Osborne dumped body in
dump used by an Ashram. Body would
not be found for 7 months.
Osborne went east and went on an
unpaved road of black slags and drifted
sands on a New Jersey barrier island. He
hid car and torched it with gasoline.
Colorado v. Walter Osborne
(cont)
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FBI investigation turned up Osborne in New Jersey
Although Osborne (discovered to be Joseph Corbett,
Jr) covered his tracks well but was writing his
itinerary on the bottom of his car.
4 depositional strata found:
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4th contained material from around New Jersey dump
where he burned car
3rd contained pink feldspars of Pike’s Peak granite – near
where body was found
2nd had materials from Morrison hogback formation –
around Coor’s rangch
1st had pink feldspars of other Front Range granites –
generally related to Rocky Mountain Front Range
Death of a DEA Agent: Enrico
Camarena
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Story of how FBI geologist, Ron Rawalt
was able to determine, with certainty,
where Camarena body was buried, thus
showing that Mexican govt. lied about
how he was killed.
He noticed a TV report of the killings. The
body was shown with soil clinging to it.
The soil was obviously of a different color
than the soil from the alleged burial site.
Death of a DEA Agent: Enrico
Camarena (cont)
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He told the govt. that he could prove, with
soil analysis alone, that Mexican govt. was
lying about the murder.
He went to Mexico and collected a
spoonful of soil from Camarena body. He
compared that to the soil from the alleged
burial site and found them to be entirely
different.
Death of a DEA Agent: Enrico
Camarena (cont)
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Soil from body
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Spoke of mountains
98% rhyolite ash (clean, high in silica, angular,
vesicular) – could be described as “airfall pumice”
Bixbyite – blacker than coal
Pink glass of exceptional depth and richness of color,
he had never seen anything like it, except in candy
2 kinds of cristobalite: opalized and clear, elongate
and faceted, clear polygonal columns (octehedrons).
Resembled branch coral. Very rare to find both types
together.
Death of a DEA Agent: Enrico
Camarena (cont)

Pinpointing location
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Research with Geological Survey and
Smithsonian minerologists located specific
location – A Jalisco state park called Bosques
de la Primvera. Cristabolite was the result of a
third-event calderea formation.
Location is on upslope of mountain in park or
park itself
Rawalt flew to Mexico as “DEA agent” (FBI
agents were not allowed in to investigate
Death of a DEA Agent: Enrico
Camarena (cont)

While Rawalt was in Mexico searching for
the area of burial, FBI was approached
about a French consultant, Loic Le Ribault.
He was the head petrologist for the French
national oil company and was said to be
able to do things geologically speaking,
that other people couldn’t do. Show him a
few grains of sand and he could tell you
where they came from
Death of a DEA Agent: Enrico
Camarena (cont)

Le Ribault

FBI tested him by giving him 3 samples:

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Ash from Mt. St. Helens
Alluvium from river delta in S. Carolina related to recent
murder
Dirt from girders taken from bomb site in Beirut, Lebanon
Ribault’s results:
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Got location of ash from Mt. St. Helens within a few miles of
source
River basin in American Southest
Bekaa valley in Lebanon – soil had been subjected to
explosion
Death of a DEA Agent: Enrico
Camarena (cont)
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Le Ribault’s contribution to Camarena case
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Was showed samples from park and body. He
said “you are there, but not there”. Right
elevation, but these are samples (from park)
from an area washing north. The site is an
area washing south.
Sand deposited by water 4-5 ft. deep in a
draw. Slope of draw <10 degrees. Shade
predominates.
Rawalt found exact location from this data.
Soil and Arsenic poisoning
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Washington State Patrol Forensic Geologist Bill
Schneck became involved in the investigation into the
serious illness of a small child caused by arsenic
poisoning.
The suspected person was absolved when an
examination of the child's house revealed a number of
mineral specimens left in the house and the yard by a
former occupant who was a mineral collector. Many of
those specimens were arsenopyrite, an iron arsenic
sulfide.
The child had been eating and chewing on the
material.
An Early Case:
The Father Patrick Heslin
Case
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In Colma, California on 2 August 1921 a priest, Father
Patrick Heslin, was kidnapped and a ransom note was
received, but there was no further contact from the
kidnapper.
The priest's body was found on a local beach by William
Hightower, a master baker. However, sand grains found
on Hightower's knife and in his room matched the beach
sand at the site where the body was found. Hightower
was convicted of the murder and sentenced to life
imprisonment in San Quentin.