Crime Scene Forensics - Studying Soil Samples

If you are a big fan of the CSI or Forensic Files TVthe day the crime was committed. Similarly, finding
shows, you may have seen the TV scientists analyzehorse dung in a soil sample could suggest that the soil
soil samples that were found at the scene of a crime.came from a horse farm and not from the suspect's
These were soil samples that were perhaps found onbackyard.
the victim's shoes but no where else to be found in theFurther forensic chemical analysis can determine
immediate vicinity of the crime scene. They could bewhether two samples share the same chemical
soil samples embedded in the tire tread of a car that isproperties. Using X-ray diffraction, the criminalist can
suspected to be used in a crime.examine and compare the minerals that are present in
Soil is not just plain dirt. It is a conglomerate of severalsoil samples. Gas chromatography/Mass
things. They include minerals, plants, animal matter, andspectroscopy (GC/MS) can be used to identify many
tiny particulates of synthetic products like glass, paint,individual components in a soil sample. Another
asphalt, cement, and other things. The contents of soillaboratory technique called differential thermal analysis
are not uniform wherever you go. They differ fromis useful. The premise behind differential thermal
one place to another. Soil found on the beach inanalysis is that soils release and absorb heat at
Ocean City, Maryland has different components fromvarying rates. In this analysis, a soil sample is heated,
soil found on the beach in Myrtle Beach, Southand the point at which the soil breaks down, melts, or
Carolina.boils is recorded. These results are then compared
The first step involved in analyzing soil samples iswith the same thermal properties of other soils to
visually and microscopically inspecting the soil to makedetermine whether or not they are consistent enough
determinations of acidity, consistency, color, and mineralto be considered a match.
content. Next, the forensic scientist looks for anyForensic laboratory science can be a powerful tool
foreign objects such as plant materials like leaves orwhen solving a serious crime such as murder.
animal material like hair, teeth, or nails. For instance,The next time you watch your favorite CSI or
finding evidence of beachfront sandy soil on theForensic Files TV show, you will have a better
carpets of a suspect's car can contradict hisunderstanding of why soil samples are important in the
statement that he had never been to the beach oninvestigation of a crime.