2009©Forensic Science Today Hair Evidence. 2009©Forensic Science Today Parts of the Hair Medulla Cuticle Cortex Follicle Root Distal end Proximal end

2009©Forensic Science Today

Hair Evidence


Parts of the Hair

Medulla

Cuticle Cortex

Follicle

Root

Distal end

Proximal end


Medulla Types

Intermittent

Fragmented

continuous


Medullas Hair in top image-

uniserial ladder medulla pattern

Hair in middle image- multiserial ladder medulla pattern

Hair in bottom image- deer medula

Deedrick, D. W. Hairs, fibers, crime, and evidence, Forensic Science Communications [Online]. (Jan 2004). Available: http://www.fbi.gov/hq/lab/fsc/backissu/jan2004/deedrick.htm

http://www.fbi.gov/hq/lab/fsc/backissu/jan2004/deedrick.htm


Cuticle Types

Coronalmouse

Imbricatehuman

Spinouscat

• Deedrick, D. W. Hairs, fibers, crime, and evidence, Forensic Science Communications [Online]. (Jan 2004). Available: http://www.fbi.gov/hq/lab/fsc/backissu/jan2004/deedrick.htm.



Human Cuticle

• Deedrick, D. W. Hairs, fibers, crime, and evidence, Forensic Science Communications [Online]. (Jan 2004). Available: http://www.fbi.gov/hq/lab/fsc/backissu/jan2004/deedrick.htm.



Medullary Index

Width of the medulla/ width of the hair shaft

If it is less than 1/3, it is human


Cortex

Contains pigment granules.

Pigment distribution Dyed hair Undyed hair

Undeveloped or missing pigments cause grey hair


Proximal End

End nearest torso

Root or no root?


Distal End End farthest from the torso


Telogen, Anagen & Categen Phases of Hair


Observe Cuticle

Type of cuticle

Is this possibly human?

Damaged or undamaged


Questions About Hair

All hair on one head the same? Different on different body areas? Tell race of person from hair? Sex of person from hair? Age of person from hair?


Comparing Hair Samples?

Comparing hair from a scene to hair from a known source?

Is it Similar? What makes it Similar?

All the characteristics found on the known hair and the questioned hair must be identical.

What does it mean to say they are consistent with one another?


Class vs. Individual

Hair has basically class characteristics

Matching distribution of pigment, medulla type and cuticle type can be found in many individuals.

Cellar material presentDNA???


Hair Collection

Cellophane tape into Petri dish or Vacuuming Choose container that will prevent

loss Label and Seal Receipt for evidence!!!


Control Samples

Determine the source of evidence Uncontaminated From known source For hair-must be pulled

50 from all over head 24 from pubic area in case of sexual

assault

Documents

2009©Forensic Science Today Hair Evidence. 2009©Forensic Science Today Parts of the Hair Medulla Cuticle Cortex Follicle Root Distal end Proximal end