Question

Answer the following questions:

1) How hair can easily transfer and lead to wrongful conviction?

2) In late 70s or even 90s did forensic scientist know that hair is easily transferable, was secondary transfer a known thing or was it simply overlooked and if we didn't have DNA analysis technology we have now would we still be using hair analysis to solve majority of the cases?

3) What are the significance of fibres in crime scenes?

Answer 1

1-DNA (deoxyribonucleic acid) is a code that programs how we will develop, grow, and function. Humans are thought to have DNA that is 99.9% identical, but the remaining 0.1% makes us individuals, marking us out as unique. The fact that humans and chimpanzees have just a 1% difference in their DNA further highlights how meaningful a small difference can be. Generally, the more closely related we are to someone, the more similar our DNA will be to theirs.

The tiny part of our DNA that is unique to us can be used to generate a DNA profile. This profile is usually represented as a graph showing different peaks, which reports the patterns at different points where our DNA is most likely to be unique.

so Basic problem in repitition of genome

2- Because in hair sample we easily find nuclear DNA but most important conserved sequencing of miitochondrial DNA

Distribution of Nuclear and Mitochondrial DNA in Hair Samples
The hair fibers (sometimes referred to as the hair shaft) are actually formed by keratinocytes, types of skin cells which are responsible for the synthesis of the protein keratin. These cells naturally die and in the process get converted from cells into a horny, tough material such as hairs. This conversion process is known as cornification, and it involves the destruction and degradation of the cell nucleus (and thus, also of the genetic material enclosed within). As a consequence of cornification, the hair shaft, which is the part of the hair that protrudes out of the scalp, does not contain any nuclear DNA.

3- fibre showing much significance in the field of criminal investigation

Fibre is regarded by many experts as the most common and integral piece of evidence located at a scene of crime. Forensic Resources ltd provides forensic fibre analysis for all forms of fibres to help support or discredited evidence used in criminal investigations.

Connecting a suspect to a crime from purely trace evidence of a very small nature is an incredibly specialised undertaking - particularly as our forensic experts are concerned not with strands of yarn, but sometimes rather minute broken fragments of individual fibres. These materials can be finer than human hair and can often be no more than a millimetre in length. Our experts follow intensive microscopic methods including separation, cleaning and mounting of fibres before undertaking comparison of a suspects clothing. Analysis of dyes and fixing agents is also paramount in the identification of fibres.

Our experts can also provide valuable associate evidence in cases such as hit and run, where crushed paint has made contact with the victims clothing, and the examination of oils, grease, wax, soil residue and vegetation can all be traced and used as evidence from the forensic study of clothing. The value of fibre identification for our experts is largely dependent on the type, colour and/or variation of colour, number of fibres found and location.

Hair and Fibres are two of the most important resources in Forensic Science and are often responsible for providing valuable clues as to the identity of an assailant or attacker. The discovery of Fibres is essential when determining what an attacker or killer was wearing at the time of an incident. Forensic Resources use forensic fibre analysisas means of determining the type of clothing worn during a incident and our experienced forensic scientists can often identify the brand of the garment and thus the manufacturer. In many instances this forensic fibre analysis technique is so successful that garments that are rare or custom made for examples suits -can be identified and a list of possible suspects can be shortlisted by the number of units sold.