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Analysis of Hair Fibers

Updated April 17, 2017

Hair analysis and hair fibre analysis are widely used in forensic sciences and in crime labs to aid in the identification and conviction of suspects. Human hairs can be transferred with contact and are the most common form of biological evidence left at a crime scene.

Collection

The collection of hair and hair fibre from a crime scene is a tedious procedure requiring tweezers and a magnifying glass or microscope.

Microscope Analysis

Hair fibres are then analysed under a microscope to identify colour, texture, shape pattern, twist, and cross-sectional appearance, as well as any other identifiable surface characteristics.

Benefits

Microscopic analysis of hair fibres can often determine the race of a suspect. It can also determine where on the body the hair was from, which has significance at a crime scene. Although sex cannot currently be determined from hair, advances in genetic research may make this a routine forensic technique.

Microchemical Analysis

Tests on the chemical composition of hair are often performed, testing for properties such as melting point, density, ash formation, tensile strength, and solubility. However, these tests destroy the hair and can only be performed once.

Root Examination

The root of hair is examined to determine how the hair was lost from the body. If the root is shown to have follicular tissue attached, forensic scientists know the hair has been forcibly removed.

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About the Author

Tommy Doc is a 2007 graduate of the University of Pennsylvania and an aspiring Internet entrepreneur. He was the sports editor for "The Pennsylvania Independent" while attaining his bachelor's degree in communications and environmental science. Doc is from Atlantic City, N.J. but has lived in Philadelphia, San Diego, New York and currently resides in Austin, Texas.