What is death banding in hair?
A postmortem root band (PMRB) is a distinct microscopic feature that is postulated to occur in hair remaining in the follicle during the postmortem interval [1] (Petraco et al., 1998). In addition, this degradation is confined to the cortex of the hair, with no apparent damage to the layers of the cuticle.
Is it possible to determine whether hair came from a deceased individual explain?
is it possible to determine whether hair came from a deceased person? do hairs in the telogen stage exhibit root banding in a deceased individual? no. The hairs from the questioned source are consistent with the hairs from a given known sample and, therefore could have come from the same source as the known sample.
What is banding in forensic science?
Also in 2005, the FBI’s Scientific Working Group on Materials Analysis (SWGMAT) released its Guidelines on Forensic Human Hair Analysis. This document defines post-mortem root banding as ‘the appearance of an opaque microscopic band near the root area of hairs from a decomposing body’ (p. 3).
Can hair alone provide absolute identification of an individual to a hair sample?
Hair comparisons are not a basis for absolute personal identification. It should be noted, however, that because it is unusual to find hairs from two different individuals that exhibit the same microscopic characteristics, a microscopic association or match is the basis for a strong association.
What conclusions can be drawn from microscopic hair analysis?
Three general conclusions can be reached as a result of microscopic hair analysis: exclusion, no conclusion, or association. Within the categories of exclusion and association, there are two subcategories (see Gaudette 1985).
Can DNA individualize a human hair?
Although it is not yet possible to individualize a human hair to any single head or body through its morphology, it still has value as physical evidence. To identify an individual from a hair sample, nuclear DNA must be obtained from the hair follicle.
What is a postmortem root band?
Can a single hair be individualized to one person?
A single hair (can, cannot) be individualized to one person by microscopic examination. Hair forcibly removed from the body (always, often) has follicular tissue adhering to its root.
What are banding patterns?
Banding patterns are patterns of light and dark transverse bands on chromosomes. The light and dark bands become apparent by staining the chromosome with a chemical solution and then viewed under a microscope. These bands describe the location of genes on a chromosome. 1.
What do microscopic hair exams determine?
A microscopic hair examination can also determine if a hair was forcibly removed, artificially treated or diseased. A comparison microscope can be used to compare a questioned hair to a known hair sample in order to determine if the hairs are similar and if they could have come from a common source.
How accurate is microscopic hair analysis?
Comparison microscopy resulted in 100 percent accuracy in associating the correct questioned hair with its known source, showing that they could reliably associate a questioned hair with a known sample.
Can hair be individualized using microscopic analysis?
The cortex is perhaps the most important component in determining from which individual a human hair may have come. Microscopic examination can also reveal the condition and shape of the root and tip.