Crime Scene Forensics - Determining the Chemical Characteristics of Trace Evidence

When studying trace evidence found at the crimeradiation emissions, the forensic scientist can reveal
scene, forensic scientists use in their arsenal toolsthe chemical characteristics of the sample. This
other than microscopes at their disposal. Using theprocedure is very useful in studying paint, hair,
following methods, which are the most commonlymetals, soil, and many other samples.
used ones, forensic scientists can ascertain the- X-ray Diffraction: In this laboratory technique,
chemical characteristics of trace evidence. This helpsX-rays are shot at objects or materials. The way the
them find out if the tested samples are the sameX-ray beams scatters displays how atoms and
and thus share the same origin.molecules in the sample are arranged. The
- Infrared (IR) Spectrophotometry: This laboratoryarrangement of these atoms and molecules in a
method requires exposing samples of trace evidencesample is referred to as a chemical fingerprint of the
to infrared radiation. Different samples absorb infraredsample. This laboratory technique is useful in studying
light at different wavelengths. It is these differencestrace evidence such as paint and soil.
that discern the one sample from another.By using these laboratory techniques to study trace
- Neutron Activation Analysis: This method is a bitevidence such as paint chips, forensic scientists can
cumbersome and requires the use of a nuclearcome one step closer in solving a crime based on the
reactor. Neutrons are shot at the sample and collidevidence left at the crime scene.
with its components. The result is that eachForensic science can help bring the offender to
component releases radiation at its own uniquejustice.
energy level. By measuring the levels of those