The article, as the title implies, is all about the forensic examination of human hairs. Hairs, like fingerprints, are one of the most common evidences collected in a crime scene. Both human and animal hair can be used in identifying and linking a suspect to the victim or the scene of the crime. Forensic microscopes, like a forensic comparison microscope, are commonly used in comparing hairs. Now, forensic microscopes together with DNA technologies, like nuclear and mitochondrial DNA (mtDNA) testing, have made hair examination more accurate.
The original text is a wealth of information regarding the physical structure of both human and animal hair. Who knew that there would be a lot of information to be gained from a single strand of hair? Forensic microscopes help determine if the hair being examined belongs to an animal or human. If it is from a human, the race and type of hair (head, limb, pubic) can be deducted based on the physical characteristics of the specimen. It could even tell whether the hair was cut by scissors or by a razor, been bleached or colored, or burned!
The contents of the article are very helpful and insightful even for those readers who are not into forensics. The basic structure and composition of a hair was discussed first. Hair was described to be mostly keratin and is divided into three regions: the cuticle, medulla, and cortex.
Examining the cuticle under forensic microscopes could be useful in identifying whether the specimen came from an animal or a human based on the shape and formation of the scale structures.
The hair’s medulla can also be used to identify the hair specimen coming from an animal or a human. Based on the medulla’s structure, animal hair was described as being very regular or well defined. A human hair’s medulla structure, on the other hand, is described as amorphous or undefined or shapeless.
Aside from the structure of the medulla, the description of the medulla’s pigment granules can classify whether the hair came from an animal or a human. Pigment granules that are concentrated toward the cuticle is indicative of human hair while pigment granules distributed in the medulla describes animal hair.
Did you know that human hair roots are club-shaped while animal hair roots are inconsistent or variable?
The article also mentioned the use of DNA techniques in partnership of forensic microscopic examination. DNA examination of a hair specimen, however, destroys the specimen. That is why it is advisable to first examine the hair specimen using forensic microscopes before forwarding the hair for DNA studies.
The collection of hair specimen in a crime scene was also described in the article. Since head and pubic hairs provide the most information about an individual, these types of hairs are frequently collected. Hair examiners, according to the article, have indicated a length of time for a hair specimen to be accurate. Exclusive of outside or environmental forces, hair from the head can retain their characteristics for up to one year while pubic hair can retain these characteristics much longer.
