a body is found in the water special care needs to be taken to decrease the
loss of any existing trace evidence. Too often personnel who recover a
body-found-in-water assume that the incident is an accident or suicide, and
assume that there will not be any useful trace evidence left on the body itself
or on articles associated with the body. Valuable trace evidence has been
successfully collected from bodies found in open water environments and bodies
that have been washed, that have helped gain successful convictions (Sweet
& Shutler, 1999, Ernos & Beyer, 1981).
it comes to analyzing fibers, one important aspect to be established is to
ensure there is some form of comparison between the fibers found associated
with the victim and fibers found associated with the offender(s). the
researcher did made of instances of characterizing the different fibres looked on
their morphologies with an optical microscope, by documenting their polymer
composition with Fourier Transform Infrared (FTIR) spectroscopy, and by
examining their colour.
Causin et al. (2005) studied poly
(ethylene terephthalate) (PET) fibers, which are common class of polyester
fibers. Polyester fibers can be more difficult to differentiate than acrylic
fibers, because polyester fibers are less variable in their monomer
composition. They studied colorless, single PET fibers that were exposed to sun
or room temperature water for three months, and compared these fibers to fiber
matches that remained protected from the elements to observe the effects of the
water and sun on such fibers. The fibers that were fully submerged in water for
three months were dried with paper towels prior to analysis. Optical microscopy
showed that submersion did not cause any notable swelling or morphological
changes. There was no change in the gauche/trans ratio between the soaked and
protected fibers. Unpolarized infrared spectroscopy was employed and no
significant differences were found between the soaked and protected fibers.
When evidence is collected, scene investigators should document as many of the
environmental variables as possible so that differences between crime scene
fibers and offender-associated fibers can be analyzed within the context of
these variables. Thorough and accurate scene documentation can help produce
more valid laboratory analyses that will stand up better in court.