Hair Analysis Trial
Hair Analysis Trial
My name is Joshua Belle and I am an expert in Hair Analysis for the purpose of forensics. I am here to present evidence to the jury. As you all know, several months ago a woman’s dead body was found in the local dump, with several markings which indicate a murder. As you will see, I have found substantial evidence linking the defendant to the crime. To start with, I will provide you with some knowledge about the structure of hair. Hair is made up of two basic parts: The follicle, which is the actively growing root or base of a hair containing DNA and living cells, and the shaft, which is a strand of hair compose of a protein called keratin. The shaft is made up of the medulla (the central core of a hair fiber), the cortex (the region of a hair located outside of the medulla containing granules of pigment), and the cuticle (the tough outer covering of a hair composed of overlapping scales). The medulla is different from person to person. Some are continuous, some are fragmented, some aren’t there at all, and some are even doubled. There are also different types of cuticles, including imbricate, which is what humans have, coronal, which is what rodents have, and spinous, which is what animals such as cats have. With a macroscopic view of hair you can see differences in color, length, and where it is curly, wavy, or straight, but that only scratches the surface of what you can see on hair. With a microscopic view you can see the medullary index (the ratio of diameter of the medulla to the diameter of the hair), cuticle type, cortex color, diameter of the hair, and much more.
Images from http://student.santarosa.edu/~lzanotti/pages/structure.html Hair found in the suspect’s car suggests that he was, in fact, the killer. The hairs found have a mudullary index of .31 (any with an index of less than .33 is human), and they all have an imbricate cuticle type. They are also blonde, thick, and curly; exactly like the
My name is Joshua Belle and I am an expert in Hair Analysis for the purpose of forensics. I am here to present evidence to the jury. As you all know, several months ago a woman’s dead body was found in the local dump, with several markings which indicate a murder. As you will see, I have found substantial evidence linking the defendant to the crime. To start with, I will provide you with some knowledge about the structure of hair. Hair is made up of two basic parts: The follicle, which is the actively growing root or base of a hair containing DNA and living cells, and the shaft, which is a strand of hair compose of a protein called keratin. The shaft is made up of the medulla (the central core of a hair fiber), the cortex (the region of a hair located outside of the medulla containing granules of pigment), and the cuticle (the tough outer covering of a hair composed of overlapping scales). The medulla is different from person to person. Some are continuous, some are fragmented, some aren’t there at all, and some are even doubled. There are also different types of cuticles, including imbricate, which is what humans have, coronal, which is what rodents have, and spinous, which is what animals such as cats have. With a macroscopic view of hair you can see differences in color, length, and where it is curly, wavy, or straight, but that only scratches the surface of what you can see on hair. With a microscopic view you can see the medullary index (the ratio of diameter of the medulla to the diameter of the hair), cuticle type, cortex color, diameter of the hair, and much more.
Images from http://student.santarosa.edu/~lzanotti/pages/structure.html Hair found in the suspect’s car suggests that he was, in fact, the killer. The hairs found have a mudullary index of .31 (any with an index of less than .33 is human), and they all have an imbricate cuticle type. They are also blonde, thick, and curly; exactly like the