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Latent Fingerprints Essay

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The visualisation of latent fingerprints is enhanced by the adherence of enhancement materials to the chemical constituents found in latent fingerprints. The most common enhancement techniques employed to improve the visibility of latent fingerprints are fingerprint powder dusting, cyanoacrylate fuming and ninhydrin [Lee & Gaensslen 2001]. These methods are inexpensive, fast and efficient. However, these techniques may affect the useful chemical characteristics and physical traces of residual evidence which can be obtained from latent fingerprints.

Fingerprint powder is commonly used on non-porous surfaces and on fixed surfaces which cannot be taken to the laboratory (e.g. windows) [Champod & Lennard 2004]. This fine powder is easy to apply with the powder particles adhering instantaneously to the greasy and sticky substances in the latent fingerprint deposit [Champod & Lennard 2004]. However, this method is not sensitive and will only adhere strongly to relatively fresh fingerprints. This is because as the fingerprint ages, the deposit dehydrates and loses its adhesiveness [Champod & Lennard 2004]. There are also limitations with the application of dusting powders. Over-dusting a fingerprint may cover finer details such as scars or smudge the prints, making it difficult to identify …show more content…

2004; Champod & Lennard 2004; Saferstein 2011]. It reacts with the primary and secondary amine groups of amino acids which are excreted from the eccrine glands resulting in a Ruhemann’s purple product [Saferstein 2011]. This chemical enhancement is nonspecific, thus it reacts with the different amino acids that are present in a latent fingerprint deposit [Saferstein 2011]. Also, due to the stability of amino acids in porous surfaces, very old latent fingerprints can be developed using ninhydrin [Bowman ed. 2004; Saferstein

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