If you are a big fan of the CSI or Forensic Files TV shows, you may have seen the TV scientists analyze soil samples that were found at the scene of a crime. Within these soil samples, there is minute evidence that can have great forensic significance.
Plant materials such as seeds, pollen, or leaves can be found not only in soil samples, but also on dead bodies, clothing, flooring, automotive carpets, tools, and many other places. These plant materials can be the subject of forensic study. Just like any type of trace evidence, plant materials can link a suspect to a crime or a crime scene. Forensic scientists many times look for leaves, stems, flower petals, bark, pine tree needles, pollen grains, and seeds because different plants are unique to different areas. The materials from those plants can help the forensic investigator determine the origin of a soil sample. For instance, if investigators find tree bark on the deer hunting viking armor hoodie of a homicide victim, but no trees consistent with the bark anywhere outside the house, the perpetrator probably brought the tree bark with him on his deer hunting viking armor hoodie or viking polo shirts . In depth study of a particular tree species from which the bark came can help investigators narrow the possibilities of a search area.
Pollen, a product of flower plants, can be very useful to the forensic laboratory scientist. Pollen grains are minute and are rarely visible. However, they are highly unique. Pollen may be found on the jeans, shirt, or hair of a victim or suspect. Pollen grains may also be found in envelopes containing a perpetrator’s ransom note. Microscopic identification of pollen grains may indicate at the victim or the offender had been in a place where the particulate plant matter was in bloom. There exist several pollen reference databases that can help the forensic scientist with identifying a particular species.
write by JUAN MONTERROZA