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Hair EvidenceHair Evidence
Many class characteristics can be determined; these characteristics can be used to eliminate suspects.
Forensic scientists can determine whether the hair was forcibly removed, damaged by burning, or artificially treated by dyeing or bleaching.
The region of the body where a hair originated can be determined with considerable accuracy by its macroscopic and microscopic characteristics.
In certain instances, a person’s race can be deduced from the hair.
Many class characteristics can be determined; these characteristics can be used to eliminate suspects.
Forensic scientists can determine whether the hair was forcibly removed, damaged by burning, or artificially treated by dyeing or bleaching.
The region of the body where a hair originated can be determined with considerable accuracy by its macroscopic and microscopic characteristics.
In certain instances, a person’s race can be deduced from the hair.
Types of Human HairTypes of Human Hair
Head hair Pubic hair Underarm hair Beard/mustache
hair Eyebrow/eyelash General body hair
Head hair Pubic hair Underarm hair Beard/mustache
hair Eyebrow/eyelash General body hair
Certain features of individual
hairs identify the region of
the body where it
originated.
Certain features of individual
hairs identify the region of
the body where it
originated.
Head hairs and pubic hairs exhibit a greater range of
microscopic characteristics than other human hairs;
therefore, head and pubic hairs are routinely forensically
compared.
Head hairs and pubic hairs exhibit a greater range of
microscopic characteristics than other human hairs;
therefore, head and pubic hairs are routinely forensically
compared.
Hair Characteristics: RaceHair Characteristics: Race Human hairs can be classified by racial origin
such as: Caucasian (European origin) African-American (African origin) Mongoloid (Asian origin).
In some instances, the racial characteristics exhibited are not clearly defined, indicating the hair may be of mixed-racial origin.
Racial indicators apply primarily to head hairs.
Human hairs can be classified by racial origin such as: Caucasian (European origin) African-American (African origin) Mongoloid (Asian origin).
In some instances, the racial characteristics exhibited are not clearly defined, indicating the hair may be of mixed-racial origin.
Racial indicators apply primarily to head hairs.
Human vs. Animal HairHuman vs. Animal Hair
How do you tell the difference?
How do you tell the difference?
Animal vs. Human Hair:Color
Animal vs. Human Hair:Color
Human hairs are generally consistent in color and pigmentation throughout the length of the hair shaft, whereas animal hairs may exhibit radical color changes in a short distance, called banding.
Human hairs are generally consistent in color and pigmentation throughout the length of the hair shaft, whereas animal hairs may exhibit radical color changes in a short distance, called banding.
Human vs. Animal Hair: Medullary Index
Human vs. Animal Hair: Medullary Index
The medulla, when present in human hairs, is generally less than one-third the overall diameter of the hair shaft. (MI = ??)
The medulla in animal hairs is normally continuous or interrupted, and it generally occupies an area of greater than one-half the overall diameter of the hair shaft. (MI = ??)
The medulla, when present in human hairs, is generally less than one-third the overall diameter of the hair shaft. (MI = ??)
The medulla in animal hairs is normally continuous or interrupted, and it generally occupies an area of greater than one-half the overall diameter of the hair shaft. (MI = ??)
Human hair is imbricate (flattened) Animal hair varies by species, but
can be spinuous or coronal, as well as imbricate
Human hair is imbricate (flattened) Animal hair varies by species, but
can be spinuous or coronal, as well as imbricate
Human vs. Animal Hair: Cuticle
Human vs. Animal Hair: Cuticle
Human vs. Animal Hair:Tip
Human vs. Animal Hair:Tip
Scissor cut or razor cut implies the hair has been “groomed”. Many animals are not groomed so if you see a scissor cut tip or a razor cut tip it might be a clue that the type of hair you are looking at did not come from an animal.
Scissor cut or razor cut implies the hair has been “groomed”. Many animals are not groomed so if you see a scissor cut tip or a razor cut tip it might be a clue that the type of hair you are looking at did not come from an animal.
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