Hair and Fibers

History Hair and fiber analysis is relatively new in forensics, but it has become extremely important. One of the first papers on hair analysis was published in France in 1857, followed by looking at hair in microscopes in the early 1900s.  The earliest use of hair analysis in forensics was when a forensic scientist used the fact that a murder victim had died his hair before the crime occurred. This small piece of evidence was used to track down the suspect, and eventually charge him for murder. Hairs can be used to identify a persons race, gender, and even age. Hair is made up of many things, the most common being protein substances and keratin. Because of hairs ability to absorb it is good to analyze hair in poison cases. Scientists can also tell if hair had fallen out, or been pulled out or if it was forcibly removed. Scientists can find what part of the body hair is from, who and what it is from and match it to suspects and victims.
Notable Cases
Two well known cases using hair and fiber analysis are the Leo Frank Trial of 1913 and the Trial of Sacco and Vanzetti.

The Leo Frank Trial involved the discovery of a thirteen year old girl in the basement of an Atlanta pencil factory. The girl had gone to the factory to collect her pay check when she was murdered. The anti-Semitism feelings of the south led to the wrong conviction of a jewish superintendent, Leo Frank.This case ended up attracted attention from the US Supreme Court and the Governor of Georgia, but neither could help protect Leo Frank from being hanged. Although originally overlooked, hair analysis was eventually used as proof by matching hairs of the victim to the crime scene.

The Trial of Sacco and Vanzetti involved two Italian anarchists, who were suspected of murder. Hundreds of thousands of people believed that this was a false conviction, that the two men were innocent. Evidence was found and many pieces of evidence were not properly analyzed. Another situation many people overlooked, the fact that one of the men could be innocent, and the other guilty. In this trial, hair found in a cap matched hairs of Sacco, proving him guilty.

 This picture shows what a hair is made up of. Each of these elements can be seen under a microscope, and the texture and color can help to identify where the hair came from. This is a human hair, animal hairs look different.

These different parts include:
The Shaft
This is the part of the hair that is visible and above the scalp.
The Root and Bulb
This is the living part of the hair that cannot be seen, it is inside the scalp. The bulb is what controls the growth of the hair.
The Papilla
This is an empty area in the bulb that nourishment for the hair comes from.

There are different layers in a hair:
The Cuticle
This is the outer layer of the shaft, and looks like fish scales. It provides the health of the hair (strength, flexibility, and sheen.)
The Cortex
This is below the cuticle. This also determines the hair color and is made of keratin protein.This layer also provides most of the volume of the hair.
Medulla
This is the very core of the hair, and in very thin hair it may not appear.


Other than hairs, fibers are very important.
Major Types of Fibers
 Cotton:

This is a soft fiber that grows on seeds. It is a very commonly used fiber, and each part of it can be used. Cotton is used in many different applications, from apparel, home furnishings, automobile and even medical and surgical.









Rayon:

This is a man made fiber, although it is not considered synthetic. It is called a manufactured regenerated cellulosic fiber. This name originates from the fact that this fiber is made from cellulose. This fiber is just as versatile and comfortable as natural fibers, such as cotton. This fiber can imitate silk, wool, cotton and linen and can be dyed in a wide range of colors.This makes a very absorbent cloth, but is not a good insulator.This fiber has low durability and wrinkles easily, it also has the lowest elastic recovery of any fiber.

Linen:

This is a plant fiber, made from the stalk of the flax plant. This is one of the earliest fibers made into string and cloth. This is also the strongest vegetable fiber, its two to three times stronger then cotton! Similar to rayon and cotton, this fiber is dyed easily and is comfortable to wear. It makes a very absorbant cloth, and is good for apparel, although it wrinkles easily (it can be pressed easily to solve this) and has poor elasticity.



Hemp:

This is a bast fiber plant that is similar to flax (linen) and ramie, therefore it possesses similar properties. Hemp excels in fiber length, strength, durability, absorbency, antimildew and antimicrobial properties. This fiber can be of different qualities, the highest coming from Cannabis Sativa, and lower qualities being Sisal and Manilla Hemp. Hemp works best in fabrics when mixed with other fibers, although high quality Hemp fabric is produced and wearable, although easily wrinkled. This fabric also withstands water better then any other textile product.

Ramie:


Hair and Fiber Collection

For hair, all samples must be handled with gloves and tweezers. The samples are carefully removed form the area and placed into labelled envelopes. These envelopes are then put into a bigger bag, as to further ensure no evidence will go missing.
*Note: If the hair is attached to something such as dried blood, do not remove it but collect the whole thing.

For fiber, use the same precautions with gloves and tweezers. Remove the samples from the scene and place them into labelled envelopes. If the fiber is so small that it may get lost, tape it down onto a piece of paper and then place into envelope. Then once again put the samples into a larger bag.

Typical Hair and Fiber Analysis
Hair and fiber analysis can be very helpful on crime scenes, and even place a suspect in custody.
Typical analysis involves analyzing hair for key features that distinguish it from other races, genders and how the hair was removed. This analysis is done through a microscope. We did this in lab:

DNA tests can also be performed on hair for more accurate results. The hair can also be used to drug test an individual.

Reliability of Hair and Fiber Crime Scene Data
This varies, and because hair can be chemically processed and changed. This makes it hard to always get perfect results, although you can undo things like coloring and perming hair, it only allows for a clearer image of what the race may be. These types of problems make it hard to always use hair as reliable evidence, although it has been done. Fibers also face problems, they cannot always be easily matched with something, and if they are because of mass production it is hard to prove what source the fiber is from.

In class we looked at hair in a microscope, and drew what they looked like. This was to help us in the crime scenes we would later analyze.