Essay on Investigation Of A Crime Scene

1183 Words Nov 22nd, 2016 5 Pages
According to Locard’s principle, at a crime scene traces are left by the perpetrator linking their presence to the scene, which can be crucial information for an investigator in a criminal investigation (Locard, 1930). Deoxyribonucleic acid (DNA) are left behind on items that are touched or handled even for a brief moment, and by swabbing the surface a DNA profile can be acquired (van Oorschot and Jones, 1997). Henceforth, there has been great interest in the conditions that allow primary, or direct transfer of an individual’s DNA onto an object or onto another individual (Meakin and Jamieson, 2013). There is the possibility of secondary, or indirect transfer, where the DNA of an individual is introduced into a crime scene by the perpetrator or through another intermediate source (van Oorschot and Jones, 1997). Secondary DNA transfer can falsely connect an individual to a crime, introduce foreign DNA into a sample being investigated, and allow professionals working in the medico legal field to falsely conclude that the recovered DNA was a consequence of primary transfer (Cale et al., 2016). The limitations and reliability of DNA analysis will not be mentioned. This essay will discuss the experimental evidence illustrating secondary DNA transfer and the different factors contributing to the phenomenon. It will provide an explanation of how the DNA of an individual, who was absent from the crime scene at the time of incident, was recovered from samples taken at the scene.…

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