This document provides an introduction to hair as forensic evidence. It discusses the history of using hair in criminal investigations, the different types and structures of hair, growth phases, locations hair evidence can be found, and methods for collection, preservation, and forensic examination. Hair can be examined to determine characteristics like the species, sex, race, and in rare cases individualization of the person it came from. Various tests are used to analyze hair evidence microscopically and chemically.

1. AN INTRODUCTION TO
HAIR AS A
FORENSIC EVIDENCE
BY:TEJASVI BHATIA

2. CONTENTS
 INTRODUCTION
 HISTORY
 TYPES OF HAIR
 HAIR STRUCTURE
 GROWTH PHASES
 LOCATION OF HAIR EVIDENCE
 COLLECTION AND PRESERVATION
 FORENSIC EXAMINATION OF HAIR
 REFERENCES

3. INTRODUCTION
 Hair is found as an evidence in various types
of crimes like murders, assaults, rapes,
abortions etc.
 Hair can withstand the effect of the various
environmental conditions as compared to
other bodily tissues.
 They are routinely examined and compared
for morphological and physical characters
for determining the site, sex, race , species
origin and for individualization etc.

4. Contd....
 The characters that are commonly used are
color, breadth of hair and medulla, scale count,
medullary index, hair index, scale count index
etc.
 In extremely rare cases, the presence of some
individual dye, contamination, some
extraordinary defects or disease in the hair can
permit individualization.
 Hair acts as an important corroborative
evidence .

5. HISTORY
 1897 – Rudolf
Virchow became
the first person to
do an in depth
study of hair.
 1906 - Hugo
Marx wrote a
paper on the use
of hair in forensic
investigations to
determine
identity.
 1931- Dr. Paul Kirk
worked on new
ways to improve
the use of hair in
forensic
investigations.
 1936-1973 : Smith,
Nickolls , Niyogi ,
Moenssons et al.,
King et al.
examined hair roots
whether the hair
has fallen naturally
or pulled out
forcibly.
Edmond Locard
(1920), noted for his
exchange principle.

6. TYPES OF HAIR
Four types of hair appear on the
bodies of human :
 Primordial
 Lanugo
 Vellus
 Terminal
In forensic examination,we deal
exclusively with terminal hair.

7. STRUCTURE OF HAIR
 Hair is an appendage
of the skin that grows
out of an organ known
as the hair follicle.
 The root portion of the
hair lies in the follicle.
 The portion above the
skin surface is called
the shaft.
 The bulb of root is
surrounded by dermal
papilla.

8. Contd…
 Hair is composed of a group of proteins
known as keratins.
 The adjacent keratin protein chains are
joined by the bonding of sulphur atoms.
 The hair shaft is composed of three
layers:
I. Outer Cuticle
II. Inner Cortex
III. Central Medulla

9. Contd…

10. 1. Cuticle
 It is a thin translucent layer
surrounding the hair shaft.
 The cuticular layer consists of
overlapping, non-nucleated, pigment
free cells which form scales.
 These scales are formed from the
specialized cells which have
keratinized in their progression from
lower part of the follicle.

11. Types of scales:
1. Coronal 2. Spinous
3. Imbricate

12. Photomicrograph of a human hair
possessing an Imbricate cuticle.
• Scale count and scale index have been used
as an attempt to individualize the hair.
•The scales of human hair are placed in the
flattened category of imbricate type.

13. 2. Cortex
•It is composed of
elongated, fusiform,
keratinized filaments
aligned in a regular array
parallel to the length of
the hair.
•Variable amount of
delicate air spaces known
as the cortical fusi are
interspersed among the
keratinized cells of the
cortex.

14. Contd…
• The coloring pigment granules
(melanin) are interspersed
throughout the cortex.
• These pigment granules are evenly
distributed or concentrated more
towards the peripheral region of
cortex of human hair.

15. 3.Medulla
 It originates from the matrix cells at the apex of
the dermal papilla.
 Large amount of glycogen is found in medullary
cells.
 The main function of the medulla is to increase
the protective properties of hair by adding
internal air spaces to the hair.
 The medulla of hair varies widely among the
different species and is one of the most valuable
morphological character available for species
origin.

16. Contd…
 Medulla may be:
1. Continuous
2. Discontinuous
3. Fragmented
4. Absent
 In humans,the medulla is
narrow,the medullary
index is 0.3 or less.
 In case of animals,the
medulla is usually broad
and occupy more than one
third of the hair width.
Photomicrograph of a hair with a clear,
continuous medulla.
Photomicrograph of a hair with
fragmented medulla
Photomicrograph of a human hair with
no medulla.

17. HAIR GROWTH
 Hair has three distinct growth
phases:
1. Anagen- the follicle actively produce
the hair.
2. Catagen-transition period from the
anagen to the telogen phase.
3. Telogen- the follicle is in dormant or
resting state.

18. LOCATION OF HAIR
EVIDENCE
 Scene of occurrence.
 On the body and clothes of victim.
 On the body and clothes of suspect.
 On the weapon of offence.
 The vehicle.
 The routes.
 Miscellaneous articles.

19. Collection and Preservation of Hair
Evidence
 Collection should be
done by hand. Sticky
tape, tweezers and lint
rollers may also be used .
 A special filtered vacuum
cleaner may be used to
collect hair from carpet,
bedding, etc.
 If the evidence is stuck to
another object , the
entire object should be
packaged and labeled.
Evidence Collecting Vacuum
Evidence Collecting Lint Roller

20. Contd…
 Once collected, the hair evidence should be
packaged into paper packets or in plastic
bags.
 Hair collected from different places should
be kept in separate packets or bags.
 If sticky tape or a lint roller are used, the
entire surface used should be packed into a
polyethylene storage bag.
 Control samples need to be collected from
both the victim and the suspect.
 The site of origin of the hair samples
collected from various parts should be
specified.

21. FORENSIC
EXAMINATION OF HAIR
 Whether the material is hair or not?
 Is the hair of human or animal origin?
 What is the site of origin ?
 To which sex it belongs?
 What is the age of the individual to whom
the hair belongs?
 Whether the hair was pulled out forcibly
or naturally?
 To which race it belongs?
 Is it possible to individualize hair or not?

22. 1. Whether the material is hair or
not?
 Physical test
 Burning test
 Microscopic test
 Chemical test
2. Is the hair of human or animal
origin?
 On the basis of scales patterns of cuticle.
 On the basis of medullary ratio.
 On the basis of color and pigmentation.

23. 3. What is the site of origin?
 Can be determined on the basis of structural
analysis.
Head Hair Pubic Hair Beard Hair

24. 4. To which sex it belongs?
 Can be determined by the presence of barr
bodies.
5. What is the age of individual to
whom the hair belongs?
 Through microscopic examination but not
definitively.
6. Whether the hair is pulled out
forcibly or naturally?
 By examining the root bulb.

25. 7. To which race it belongs?
I. Negroid
II. Mongoloid
III. Caucasian
8. Is it possible to individualize the
hair or not?
 It is not possible to individualize the
hair and say that they belong to a
particular person.

26. References
 James, Stuart: Forensic Science. 2. Boca Raton, FL: CRC Press, 2005.
 Saferstein,R.(1982): Forensic Science Handbook,Vol.I,II,III, Prentice Hall, New Jersey;
Pg no.184-209.
 Sharma B.R.: Forensic Science in Criminal Investigation & Trials,2003; Pg no.679-689.
 Robertson,J.(1996): Forensic Examination of Hair, Taylor and Francis,USA.;Pg no. 163-
186.
 Girard, James E.: Criminalistics: Forensic Science and Crime. 1. Sudbury, MA: Jones
and Barlett Publishers Inc., 2008.
 Saferstein, Richard: Criminalistics: An Introduction to Forensic Science. 9. Upper
Saddle River, NJ: Pearson Prentice Hall, 2007.
 Deedrick, Douglas: "Hairs, Fibers, Crime and Evidence." Forensic Science
Communications 2.3July 2000 16 003 2008
<http://www.fbi.gov/hq/lab/fsc/backissu/july2000/deedric1.htm>.
 Kathy, Steck-Flynn: "Trace Evidence: Hair." Crime and Clues: The Art and Science of
Criminal Investigation. 03 009 2006. 16 Mar 2008
<http://www.crimeandclues.com/hair_evidence.htm>.
 Bisbing, Richard E.: (2001) Finding Trace Evidence. in Mute Witnesses: Trace Evidence
Analysis. Houck, Max., (ed.) Academic Press, San Diego, California
 www.coolphysics.org/Hair,%20Fiber,%20and%20Paints%2005.ppt