The Federal Bureau of Investigations (FBI) has collected and studied soil samples, minerals, and other Earth material for criminal investigations since 1935 and thousands of cases involving Earth materials are studied in the United States each year. Throughout the world soil is usually collected at crime scenes, is routinely studied at crime labs, and is often used as physical evidence during crime trials.
Following are some real-life stories of crimes that were solved using Earth materials, thorough investigative work, and dedicated, professional scientists who studied soils and geology to become knowledgeable in their field. So you see, there really is more to soil than what's under foot!
A crime had been committed in the foothills of the Rocky Mountains, near Denver, Colorado. One month later a burning vehicle was found at a dump in New Jersey (on the East Coast of the United States). Soil samples were taken from the fender of the burning car and were studied by Forensic Geologists. Analyses of the soil samples showed there were four layers of soil that had built up under the burning car's fender. The outer, most recently deposited layer of soil was from the New Jersey dumpsite. The three inner layers of soil contained minerals from the Rocky Mountain Front area near Denver, Colorado
Forensic geologists obtained 360 soil samples from the Rocky Mountain Front area to compare them with those found under the fender of the burning car in New Jersey. Soil samples were also taken from the victims ranch. One of the three inner layers of soil under the suspect's car's fender matched the soil sample Forensic Geologists obtained at the crime scene. The second inner layer of soil under the suspect's car fender matched the soil sample Forensic Geologists obtained at the victim's ranch. The first inner layer of soil did not match any of the 360 soil samples taken by the Forensic Geologists but was determined to have originated from the Denver area. The suspect was convicted and jailed based upon the results using soil sample comparisons.
In the case of stolen potatoes on the east coast of the United States, a suspect who possessed the questionable potatoes was convicted of stealing them once analysis of the soil on the potatoes determined that the superphosphate in the soil that was clinging to the potatoes matched the soil from the farm where the potatoes were grown. The farm's soil contained a significant build up of phosphate because the farm was heavily fertilized with nitrogen, potash, and phosphate (phosphate doesn't leach out of the soil as readily as potash and nitrogen).
In another case, tobacco was reported stolen from a farm. Soil samples were taken from the farm where the tobacco had been stolen, and samples were also taken from the leaves of the stolen tobacco and from the suspect's farm. Soil comparison studies indicated that the soil on the stolen tobacco leaves did not match the soil samples taken from the suspect's farm, but matched soil samples taken from the farm where the tobacco was reported stolen. The suspect was arrested based upon the resulting soil sample comparisons.
Microscopic fossils called diatoms were once very prominent on Earth, and collectively deposited to form a sedimentary rock called diatomaceous earth. Some manufaturers use diatomaceous earth for insulating safes, that are used to store valuables. Burglary crimes have been solved by examining white specks from suspects' hair and clothing to determine that the specks were actually diatoms that came from broken safes at crime scenes, and not dandruff as the suspects had claimed.
If you would like to learn more about the interesting and exciting world of soil, check with your local library or on the World Wide Web. You just might learn something you'd never thought about before!
Information contained in"Secrets Hidden in Soil" was derived from "Forensic Geology" by R. Murray and J. Tedrow, Rutgers University Press, 1975. ISBN 0-8135-0794-4. Also, special thanks to Dr. Richard Arnold, USDA, Natural Resource Conservation Service/Soil Survey Division, Washington, D.C.
