Forensic Textile – An Overview
Shubham Anil Jain
Aditya Birla Fashion and Retail Limited
Forensic textile is defined as a huge field and textile in forensics and a very important function of it. In this sector, basically a damage cloth or textile is deeply investigated to find out important clue and information about the incidents. It is also important to know if victim is hit by bullet, arrows, crossbow etc. Currently, it is seen that acid attack is very high. By this technique investigator can search it out what kind of corrosive substance is thrown on individual or on other substance. Here, various techniques are used to find out information are refractive indices, morphology, color difference, polarized light microscopy, UV microspectrophotometry and infrared spectroscopy etc.
Textile examination is important in forensic because there are many conditions when analyzing textile in forensics is necessary to find out clue and information such as:
- Investigate Animal fiber at crime scene.
- When it is hanging case, then fiber from victims’ neck is examined to see if it matches with the fiber of hanging material.
- Forensic investigation of all type of textile fiber.
- Find out the percentage of wool from disputed blanket.
- To carry out fiber analysis as trance evidence from crime scene like murder, rape, accident, etc.
- Even, many times two pieces of textile are compared to find out common factor in them, etc.
Types of Textile Used for Forensic Investigation:
A textile raw material, which is characterized by flexibility, fineness and high ratio of length to thickness is called a fiber. In textile science, fibers are generally categorized as being natural or man-made. Natural fibers are further subdivided into animal, vegetable, and mineral fiber. Man-made fibers are subdivided into synthetic-polymer, natural-polymer and other. It is found that, most forensic scientists would use an optical microscope to carry out fiber identification, low-magnification scanning electron microscopy is also very helpful as it provides improved depth of field. It is suggested that, fiber identification should always start at the macro-level by taking into consideration of the length, crimp (waviness), color, thickness and consistency of a group of fibers.
By the process of spinning, fibers are usually converted into yarns before they are used in textile products. Initially, yarns are referred to as threads. A material of substantial length and relatively small cross section consisting of fibers and/or filaments with or without is known as yarn. In textile science, yarns are categorized as being simple, composite (blend), or complex (fancy). Basically, yarns can be twisted in two directions at the time of manufacturing process; these directions are known as ‘S’ and ‘Z’ twist. The direction or angle of twist for a ply yarn is different as compared to a single yarn to ensure that the yarn is balanced, that is, it is unlikely to snarl or untwist. The level of twist, i.e, number of twists per unit length affects the properties of the yarn.
Simply, yarns are used to manufacture fabrics; A manufactured assembly of fibers and/or yarns that has considerable surface area in context to its thickness and sufficient inherent cohesion to give the assembly mechanical strength is called as fabric. From a forensic perspective, fabrics of interest are woven fabrics such as apparel e.g. shirts/blouses, suits, trousers/and home furnishings e.g. curtains, carpets, bedding as well as knitted fabrics e.g. underwear, jumpers, T-shirts.
The first product composed of fabrics that may come in mind of everyone is apparel. Any personal outfit, garments, clothing or attire, including headwear and footwear manufactured from fabric is known vas apparel. Humans cover themselves for a many reasons such as for thermal neutrality, protection e.g. fire fighters, use of helmets, body armour, gender differentiation, self-identity, etc. The term ‘dress’ is defined as “gathering of body modifications and supplements which not only includes clothing but also hair, skin, breath and many accessories. It is further categorized as,
- Women’s wear
- Men’s wear
- Children’s wear
5. Household Textiles:
The another common place to find textile products is inside the house. These household textiles sometimes can be used for both functional and decorative purposes. It includes:
The popular choice for floor coverings are carpets. It is found that, modern carpets and rugs are often an inexpensive choice because of the popularity, availability and affordability of polyamide (nylon) fibers.
b) Furnishings (Curtains/Drapes/Furniture):
The house consists of many soft furnishings in addition to floor coverings, which includes sofas, chairs, ottomans, curtains and drapes are all commonly made of textiles.
c) Linens (Towels, Sheets, Bedding):
Nowadays, homes are covered with many other sorts of textiles such as bedding, sheets, quilts, duvet/doona, pillows, mattresses, mattress underlays, etc.
d) Building Materials (Insulation):
Currently, due to enhancement of technology textile materials are also found within building structures, most often in the form of building insulation e.g. fiberglass batting or polyethelene house wrap.
Forensic Textile Damage Analysis:
1. Blunt force damage:
This type of damage is typically characterized by tearing/ripping and punching/kicking and is generally a all together phrase for damage not caused by a sharp implement. This simply occurs when textiles or garment are placed under strain, for example, by being grabbed and pulled, until the fabric tears. With the recent research in this area includes a study by Daroux et al, which highlights the effect of laundering on blunt force impact (BFI) on fabrics. The authors suggested that the majority of research in textiles damage highlights mainly on stab cuts and there is very little on BFI other than an examination of the associated injuries.
2. Sharp force damage:
When this type of damage is concerned, it referred to as stab cuts, whereby a sharp weapon has gone through a piece of fabric, which leaves a hole that reflects the cutting implement itself. Not only does the implement itself affect the shape and size of the cut, but the action can have a big effect.
3. Projectiles damage:
This damage is particularly caused by any object that is protruded through the air and typically inclined to penetrate the body. For example, bullets discharged from firearms, but it also includes air pellets, arrows, and crossbow bolts.
4. Damage in sexual assault cases:
The cases in damage in sexual assault cases are blunt force damage. This can result in very high and complex damage patterns to the clothing. Although by no means ultimate, the presence of significant damage to the clothing will be proof of absence of consent in sexual assault cases.
Currently, it is clear that forensic textile science is a relatively young discipline; fiber recognition is the most established component of this discipline. As discussed in article textile products of interest to forensic scientists consists of individual fibers, yarns, fabrics, apparel, household textiles and furnishings. These are often found to be potential evidence in criminal investigations; while typically supporting in nature. Of particular interest is damage happened to apparel during a claimed incident, fiber identification with respect to trace evidence and blood staining and/or patterns on fabrics.
- Forensic Textile Science, Edited by Debra Carr
- Role of Textiles in Forensic, https://www.textileblog.com/role-of-textile-in-forensics/
- Forensic textile damage analysis: recent advances, https://www.dovepress.com/forensic-textile-damage-analysis-recent-advances-peer-reviewed-fulltext-article-RRFMS#
- Forensic Analysis of Textile Synthetic Fibers Using a FT-IR Spectroscopy Approach
- Abdulrahman Aljannahi, Roudha Abdulla Alblooshi, and Sanjay Modak
You may also like:
Founder & Editor of Textile Learner. He is a Textile Consultant, Blogger & Entrepreneur. He is working as a textile consultant in several local and international companies. He is also a contributor of Wikipedia.