Hair and Fiber Analysis

In 1857, the first scientific report regarding the scientific study of hair came out, which introduced the world to the concept of using hair in criminal investigations. The concept grew extremely quickly after the microscopic examination of hair came about in the early 1900’s. Since then, a series of literary works came out about the analysis of hair, which established hair analysis as a viable mean of use in criminal cases for investigators.

Fibers are also usable in criminal investigations. They can be used to place a suspect at a certain area that is found to have similar fibers. Some major types of fibers include polyester, cotton, nylon, silk, and wool. Each fiber has distinguishing features when viewed under a microscope. However, due to increased quality of these materials by manufacturers, sometimes certain fibers are difficult to differentiate from one another.

Fibers can place a suspect at a certain place. This is because fibers from one place can be transferred to a suspects clothing, and from there to the suspect’s car or other belongings that fibers can attach to. Hair samples would prove that the suspect was with a certain person, and depending on the condition of the root of the hair, it can be determined if there was any form of struggle; if the root is torn or has a hint of blood, then it would be revealed that a struggle took place. If the hair or fiber is visible, it can be gathered by simply picking it up with your fingers. Fibers or hairs that are smaller can be gathered by using tape to stick to the item and remove them.

Hairs and fibers are analyzed by viewing them through microscopes. Hairs have distinct features in regards to determining the suspect’s ethnicity. For example, Asian hair is very dark when compared to African hair, which is brown. By observing a hair sample through a microscope, an investigator should be able to determine the race of the person. Fibers can be identified by comparing them to other known samples. For example, if there was a question as to what type of fiber a sample is, it could be compared to other known samples in order to be identified.

Hair and fiber data is relatively useful in the solving of crimes. As previously mentioned, the samples can place a suspect at a certain are or with another person, can determine if a struggle occurred, and can determine the race of a person. However, it cannot be used place a date of occurrence or a face on a particular crime/suspect.

Hair samples were used in a case involving the murder of a US drug agent in 1985. Investigators found that hair in the house of the agent matched the hair of the defendant accused of the agent’s murder. However, as previously mentioned, this does not solidly prove that the defendant committed the murder, but does place him in the house of the agent, which the defendant had originally denied.

 

http://articles.latimes.com/1990-06-20/local/me-174_1_hair-fibers
http://www.centralreg.k12.nj.us/webpages/SHopson/files/hair.pdf
http://www.hshairclinic.co.uk/_images/hair_structure.jpg
http://www.crime-scene-investigator.net/collect.html#4
http://www.ehow.com/about_6102496_forensic-science_-hair-fiber-analysis.html