Whena body is found in the water special care needs to be taken to decrease theloss of any existing trace evidence. Too often personnel who recover abody-found-in-water assume that the incident is an accident or suicide, andassume that there will not be any useful trace evidence left on the body itselfor on articles associated with the body. Valuable trace evidence has beensuccessfully collected from bodies found in open water environments and bodiesthat have been washed, that have helped gain successful convictions (Sweet& Shutler, 1999, Ernos & Beyer, 1981). Whenit comes to analyzing fibers, one important aspect to be established is toensure there is some form of comparison between the fibers found associatedwith the victim and fibers found associated with the offender(s). theresearcher did made of instances of characterizing the different fibres looked ontheir morphologies with an optical microscope, by documenting their polymercomposition with Fourier Transform Infrared (FTIR) spectroscopy, and byexamining their colour. Causin et al. (2005) studied poly(ethylene terephthalate) (PET) fibers, which are common class of polyesterfibers.
Polyester fibers can be more difficult to differentiate than acrylicfibers, because polyester fibers are less variable in their monomercomposition. They studied colorless, single PET fibers that were exposed to sunor room temperature water for three months, and compared these fibers to fibermatches that remained protected from the elements to observe the effects of thewater and sun on such fibers. The fibers that were fully submerged in water forthree months were dried with paper towels prior to analysis. Optical microscopyshowed that submersion did not cause any notable swelling or morphologicalchanges.
There was no change in the gauche/trans ratio between the soaked andprotected fibers. Unpolarized infrared spectroscopy was employed and nosignificant differences were found between the soaked and protected fibers.When evidence is collected, scene investigators should document as many of theenvironmental variables as possible so that differences between crime scenefibers and offender-associated fibers can be analyzed within the context ofthese variables. Thorough and accurate scene documentation can help producemore valid laboratory analyses that will stand up better in court.