Forensic origins

It should be understood that the reported practices of polymer/additive analysis, being the focus of this book, equally well apply to additive analysis of rubbers, textile fibres, surface coatings, paints, resins, adhesives, paper and food, but specific product knowledge gives the edge. Both fresh and aged materials may be analysed, as well as those of both industrial and forensic origin. 

Criminalistics and trace evidence are both terms that apply to all types of physical material that may be circumstantial evidence in the trial of a case. Most often experts who are identified as criminalists, microanalysts, or trace evidence examiners analyze a variety of types of trace evidence. They carry out three types of identification. First is to determine the nature of small items of trace evidence. After this forensic experts compare the trace evidence with known materials for the purpose of determining the origin of the evidence. The third type of criminahstics investigations is performed in order to identify an individual to whom the trace belongs. For this purpose population studies using statistics (especially the probabilistic approach of Bayesian theory) and chemometrics methods are utilized. 

Lundegard, P. D., Haddad, R., and Brearley, M., 1998, Methods Associated with a Large Gasoline Spill Forensic Determination of Origin and Source Environmental Geosciences, Vol. 5, No. 2, pp. 69-77. 

Characterization and origin identification of explosives is important in forensic analysis of post-explosion residues. In addition to the type of explosive used in a... 

J.D. KeUeher, Explosives residue origin and distribution . Forensic Sci. Commim., 4 (2002). 

The New Chemistry is a set of six hooks intended to provide an overview of some areas of research not typically included in the beginning middle or high school curriculum in chemistry. The six hooks in the set—Chemistry of Drugs, Chemistry of New Materials, Forensic Chemistry, Chemistry of the Environment, Food Chemistry, and Chemistry of Space—are designed to provide a broad, general introduction to some helds of chemistry that are less commonly mentioned in standard introductory chemistry courses. They cover topics ranging from the most fundamental helds of chemistry, such as the origins of matter and of the universe, to those with important applications to everyday life, such as the composition of foods... 

The identification and quantification of active ingredient(s) in a seized material is of great forensic relevance as it enables to qualify the material as an illicit drug or not. In addition, the profiling of street drugs may allow to infer on origin and distribution routes of a confiscated drug. 

Peroxide explosives are potent explosives that can be made starting from common and easy to obtain raw materials. The analysis of triacetone triperoxide (TATP) and hexamethylenetriper-oxidediamine (HMTD) was successfully carried out by HPLC-APCI-MS in a powder sample as well as in post-blast extracts originating from a forensic case [134]. After RP separation on a C18 column using a methanohwater (75 25 v/v) mobile phase containing ammonium acetate (2.5mM) at a 0.4mL/min flow rate, detection was carried out in positive ion mode. MS-MS analysis of [TATPh-NH4]+ and [HMTD - H]+ as precursor ions was necessary in order to achieve the required sensitivity in the analysis of postblast extracts (LOD 0.8 and 0.08 ng on column, respectively). 

DNA Deoxyribonucleic acid is the repository of hereditary characteristics. The most commonly described form of DNA is the double-stranded form, arranged as a helix. Chromosomes are composed of double-stranded DNA. So called DNA fingerprinting offers a basis for evaluating the probability that blood, hair, semen or tissue samples originate from a given person, and thus offers a forensic tool as well as a means to determine lineages of humans and animals... 

Samples for analysis can come from products of vegetable or animal origin (milk, meat), water, air (ashes emitted by an incinerator) or soils in which elements are present over a wide range of concentrations (from manure spreading on agricultural land to industrial sludge). This method also has applications in the area of forensic sciences and clinical medicine (tissue analysis or biological fluids). 

Nature, Distribution, and Origin of Soil Materials in the Forensic Comparison of Soils... 

Soil formation, or pedogenesis, is a major activity for pedologists. The origins of soil attributes, distinctive horizons, and profiles must be understood to develop conceptual models for soil evolution over both long and short time periods (e.g., Smeck, Runge, and MacKintosh 1983). Such models have intuitive, predictive power in the forensic comparison of soils. 

Postmortem changes at the hair root (proximal) end in 22 forensic hair samples derived from decomposed scalps included fibers with dark stained bands located toward the proximal end, defined as postmortem root banding, as well as unstained fibers with hard points or brush-like ends (Linch and Prahlow 2001). There remains little evidence as to how these different microscopic features originate, but postmortem root banding probably results from putrefaction and is not noted in older hair from archeological remains. 

Ubelaker, D. H. (2001). Artificial radiocarbon as an indicator of recent origin of organic remains in forensic cases. /. Forensic Sci. 46,1285-1287. 

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