Analysis of Natural and Manufactured Fibres in Criminalistics
Types of Fibers and Challenges in Forensic Analysis
Natural Fibers
Cotton Fibre
Cotton and wool are natural fibres that can be used as trace evidence in criminalistics. Plants produce cotton fibre, which is widely used in the textile industry. Cotton is characterised by a structure with twisted ribbon-like shapes and a flattened appearance (Liu et al., 2022). Analysing cotton can be challenging for criminologists due to its common availability in different environments (Aditi, 2023).
Wool Fibre
Meanwhile, wool fibre is derived from sheep hair and other animals such as goats and llamas. A scaly surface and a distinctive crimped structure characterise wool. Analysing wool as evidence presents the challenge of identifying a specific animal breed, processing methods, and additional dying technology used.
Manufactured Fibers
Polyester
Polyester and acrylics are examples of manufactured fibres that criminalists may encounter. Petroleum-based chemicals produce polyester synthetic fibres, which can be used in clothing and upholstery (Liu et al., 2022). The major problem when analysing polyesters is that they are commonly produced and found in many environments (Zapata et al., 2022). Moreover, it is difficult to individualise polyester samples due to their lack of distinct characteristics.
Acrylics
Meanwhile, acrylics are derived from acrylonitrile and used as a wool substitute (Aditi, 2023). The less distinctive characteristics of acrylics and their wide use in clothing make them challenging to analyse in criminalistics.
Challenges in Analyzing Fibers in Criminal Investigations
Natural and manufactured fibres left behind in a crime scene are not visible, so specialised tools and methods are required to detect them.
Techniques for Hair and Fiber Identification
Microscopic Analysis of Hair and Fibers
Microscopic examination and DNA analysis are standard methods used to analyse hair and fibres for identification (Zapata et al., 2022). The microscopic examination involves the use of a microscope to identify the colour, scale patterns, texture, and diameter of the hair or fibre (Aditi, 2023). The method involves using known samples, which are compared with collected evidence from crime scenes.
Chemical and Instrumental Methods for Fiber Identification
On the other hand, DNA analysis examines genetic materials from hair follicles or cells attached to fibres (Zapata et al., 2022). The genetic information collected is crucial for the individualization of the trace evidence under investigation. The two techniques must be associated with expert judgement for substantive results.
References
Aditi, G. K. S. (2023). Forensic analysis of dyed textile fibers with various analytical techniques: An updated review. Journal of Pharmaceutical Negative Results, 14(3), 2812–2823. Web.
Liu, L., Levin, M. J., Klimscha, F., & Rosenberg, D. (2022). The earliest cotton fibers and Pan-regional contacts in the Near East. Frontiers in Plant Science, 13. Web.
Zapata, F., Ortega-Ojeda, F. E., & GarcĂa-Ruiz, C. (2022). Forensic examination of textile fibers using Raman imaging and multivariate analysis. Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, 268, 120695. Web.