(Forensic Pollen Analysis)<br />Vincent Lee Medicolegal Death Investigation<br />Forensic Palynology <br />
What is Forensic Palynology?<br />Study of pollen (spores) or powered material<br />Purpose<br />Criminal Identification<br />Location of crime<br />Moment in time the crime occurred<br />Locard’s Exchange Principle <br />states that when two objects come together, there is always a transfer of material.<br />U.S provides an ideal setting to solve criminal/civil cases.<br />Varied ecology, plant diversity, microhabitats, extensive pollen records.<br />i.e. Artic Tundra, Deciduous Forests, Deserts, Tropical Rain forests<br />Not fully accepted in U.S, but is commonly used in other countries.<br />Is it a reliable technique for association of an individual or object to a unique crime scene or geographical region?<br />
Pollen Characteristics<br />Carries the male sex cells of higher cone- and flower-bearing plants from one plant to another of the same species.<br />includes spores, which are the reproductive bodies of the lower plants (i.e. ferns/fern allies) and plant allies (i.e. algae, ferns, fungi, mosses, liverworts, and lichens.)<br />The success of forensic pollen analysis comes from its unique morphology, which allows for the identification of specific plant taxa.<br />Abundant<br />Very small in size<br />Outer cell wall (called exine) resistant to mechanical/biological/chemical degradation<br />Sporopollenin – compound responsible for resilience of pollen<br />Allows pollen to be preserved on a variety of media over many years.<br />Can even be found in burnt or destroyed matter.<br />
Case Study: unusual appearance of a common pollen type indicates scene of crime<br /><ul><li>Sexual assault on young woman.
All Coprosma had identical morphology to control</li></li></ul><li>Forensic Palynology: Strengths and weaknesses Indications<br />Strengths<br />Pollen can be found on an assortment of unusual surfaces <br />including condoms, counterfeit bank notes, painted works of arts, grease on guns, lungs, medicinal tablets, stomachs, and dusty foot impressions.<br />Weakness<br />Many law enforcement agencies have never heard of forensic pollen studies and thus are often skeptical and do not see the need to collect appropriate samples from the scene.<br />Proper evidential sample collection must be carefully taken from the scene to avoid contamination. Requires trained forensic palynologists.<br />the collection of control samples should be selected to encompass the potential area represented by the evidential samples and also to eliminate other areas that could not be represented by the samples<br />control samples may be skewed by an over abundance of one pollen type.<br />Plant samples should not be stored in plastic bags because potential moisture can start microbial decomposition of the pollen.<br />Usually destructive to the sample.<br />pollen evidence is purely circumstantial, in that it may indicate where an event had taken place and who was present, but not that the accused had actually done anything to the victim.<br />
Discussion<br />Forensic palynology can play a role as a supporting tool in a multidisciplinary approach with other forensic techniques.<br />In effect, this will eventually lead to a study on full forensic environmental analysis of crime scenes that are not limited to just botany or geoscience.<br />In the hands of a skilled forensic palynologist, pollen’s subtle advantages can become a powerful tool.<br />Look at morphology to identify species. (i.e. specific shape, sculpture patterns on surface, wall structure etc.)<br />It is obvious that forensic palynology is versatile and convenient when coupled with other techniques.<br />Control samples should be taken as soon as possible by a trained individual.<br />Although the sample amount required for forensic pollen analysis is very small (1g), there is often no control over the size of evidential samples, which may vary from a few hundredths of a gram to slightly larger amounts. <br />Most of the sample will be prioritized to be used for other better accepted analytical techniques, especially forensic DNA analysis.<br />United Kingdom’s creation of an Environmental and Forensic Ecology Unit, there is hope that it will soon become commonplace in the U.S and other countries.<br />
Conclusion and Future<br />Despite its shortcomings, forensic palynology can play a role as a supporting tool coupled with other forensic techniques.<br />Environmental analysis can provide a potent tool in determining the nature and details of the events that may have happened at crime scenes.<br />Evidently, the future of environmental analysis, including forensic palynology, will require a comprehensive research and investigative team for federal, provincial, state or local agencies, eventually leading to a special forensic ecology unit.<br />A well documented high profile criminal/civil case in which forensic palynology analysis plays a significant role may be able to propel the technique to be routine in investigations.<br />Associate an individual or object to a unique crime scene or geographical region.<br />It may also link an item to a scene or a suspect<br />Forgery, rape, homicide, genocide, terrorism, drug dealing, assault & robbery, arson, hit & run, counterfeiting, illegal importation, environmental preservation, illegal fishing, and pollution. <br />
References<br />Editorial (2006). Forensic palynology: Why do it and how it works. For. Sci. Intl. 163, 163-172. <br />Bryant, V.M. and Jones, G.D. (2006) Forensic palynology: Current status of a rarely used technique in the United States of America. For. Sci. Intl. 163, 183-197.<br />Mildenhall, D.C. (2006). An unusual appearance of a common pollen type indicates the scene of the crime. For. Sci. Intl. 163, 236-240. <br />Brown, A.G., Smith, A., and Elmhurst, O. (2002) The combined use of pollen and soil analysis in a search and subsequent murder investigation. J. of For. Sci. 47, 614-618.<br />