WarmUp Find the 6 differences between the two

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The answers are … Answers: Woman’s hair, boot, glove, belly button, wall socket, dress Source: http: //www. slylockfox. com/arcade/6 diff/index. html

Soil Evidence

Forensic Geology The legal application of earth and soil science Characterization of earthen materials that have been transferred between objects or locations and the analysis of possible origin or sources

Forensic Geologist Tools Binocular microscopes Petrographic microscopes X-ray diffraction Scanning electron microscopes Microchemical analysis

Forensic Geology History 1887– 1893—Sir Arthur Conan Doyle wrote about scientific ideas and techniques for solving crimes in his writings of Sherlock Holmes. This included information about soil and its composition which had never actually been used. 1893—An Austrian criminal investigator, Hans Gross, wrote that there should be a study of “dust, dirt on shoes and spots on cloth. ” He observed, “Dirt on shoes can often tell us more about where the wearer of those shoes had last been than toilsome inquiries. ”

Forensic Geology History 1904—Georg Popp, a German forensic scientist, presented the first example of earth materials used as evidence in a criminal case, the strangulation of Eva Disch. 1910—Edmond Locard, a forensic geologist, was most interested in the fact that dust was transferred from the crime scene to the criminal. This helped to establish his principle of transfer.

Soil A. Definition—naturally deposited materials that cover the earth’s surface and are capable of supporting plant growth B. The Earth 75%—oceans, seas and lakes 15%—deserts, polar ice caps and mountains 10%—suitable for agriculture 8

C. What Is Soil? • Mixture of organic and inorganic material • May range from 100% inorganic to nearly 100% organic • Inorganic part is minerals • Organic part is decayed plant and animal material and is sometimes called humus

D. Profile – – Soil Topsoil Subsoil Parent material Soil horizon E. Composition – – – – Sand - inorganic Silt – medium size Clay – small, sticky Organic matter Loam - mixture Peat – more than 20% humus Chalk – basic, soft, soil with minerals 10

Soil – needed for growing F. Nutrients—macro § Nitrogen § Phosphorus § Potassium § Calcium § Magnesium § Sulfur 11 G. Nutrients—micro § § § § Manganese Iron Boron Copper Zinc Molybdenum Chlorine

Probative Value of Soil § Types of earth material are virtually unlimited. They have a wide distribution and change over short distances. § As a result, the statistical probability of a given sample having properties the same as another is very small § Evidential value of soil can be excellent 12

Increasing Probative Value § Rare or unusual minerals § Rocks § Fossils § Manufactured particles 13

Minerals § More than 2000 have been identified § Twenty or so are commonly found in soils; most soil samples contain only 3 to 5 § Characteristics for identification—size, density, color, luster, fracture, streak, or magnetism 14

Rocks § Aggregates of minerals § Types § Natural—like granite § Man-made—like concrete § Formation § Igneous § Sedimentary § Metamorphic 15

Sand Characteristics § Composition is based on the material of the source; also gives the sand its color § Texture is determined by the way the source was transported § Shape § Grain size § Sorting 16

Sand Types Continental sands—formed from weathered continental rock, usually granite and quartz Ocean floor sands—formed from volcanic material, usually basalt Skeletal sands – formed by organic materials. (shells, algae, et), indicate warm water life Precipitate sands —formed when calcium ions from underground springs precipitate with carbonate ions in the salt water of a salt lake

Source 1 – Significance of Soil • Soil is class evidence - cannot be individualized to a particular location – There is no classification system for soils – Soils can be easily transported – Soils within a few meters horizontally or vertically differ

Source 2 - Soil Evidence § Class characteristics—the type of soil may have similar characteristics at the primary and/or secondary crime scene, on the suspect or on the victim § Individual characteristics—only if the soil has an unusual or specialized ingredient such as pollen, seeds, vegetation, or fragments. 19

Soil Comparisons § May establish a relationship or link to the crime, the victim, or the suspect(s) § Physical properties—density, magnetism, particle size, mineralogy § Chemical properties—p. H, trace elements 20

Forensic Analysis of Soils • Bulk analysis – Density gradient – Particle size distribution (sieving) • Inorganic components – 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

Collecting Soil at a Scene 1. Collect samples ASAP 2. Collect baseline samples and samples that look different or out of place 3. Collect from different locations (4 tbs. min) 4. Collect from compass points around crime scene and again 20 to 25 feet away 5. Include location of samples on sketch 6. Package separate from other evidence 7. Document the collection

Death of a DEA Agent: Enrico Camarena • 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) • 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) • Soil from body – 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 – 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 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: • 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: • 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) • Le Ribault’s contribution to Camarena case – 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.