2009©forensic science today hair evidence. 2009©forensic science today parts of the hair medulla...
TRANSCRIPT
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
Medulla Types
Intermittent
Fragmented
continuous
2009©Forensic Science Today
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
2009©Forensic Science Today
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.
2009©Forensic Science Today
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.
2009©Forensic Science Today
Medullary Index
Width of the medulla/ width of the hair shaft
If it is less than 1/3, it is human
2009©Forensic Science Today
Cortex
Contains pigment granules.
Pigment distribution Dyed hair Undyed hair
Undeveloped or missing pigments cause grey hair
2009©Forensic Science Today
Proximal End
End nearest torso
Root or no root?
2009©Forensic Science Today
Distal End End farthest from the torso
2009©Forensic Science Today
Telogen, Anagen & Categen Phases of Hair
2009©Forensic Science Today
Observe Cuticle
Type of cuticle
Is this possibly human?
Damaged or undamaged
2009©Forensic Science Today
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?
2009©Forensic Science Today
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?
2009©Forensic Science Today
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???
2009©Forensic Science Today
Hair Collection
Cellophane tape into Petri dish or Vacuuming Choose container that will prevent
loss Label and Seal Receipt for evidence!!!
2009©Forensic Science Today
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