NIJ Advanced Forensic Microscopy: Hair & Fibers

Course Outline & Syllabus

Polarized light microscopy will be used for the characterization of human and animal hairs, synthetic fibers, and naturally occurring fibers. Course instruction will emphasize fiber morphology and optics, including chemical and physical properties as methods of identification.

Prerequisite: The Forensic Polarized Light Microscopy (PLM) course serve as a prerequisite for the advanced courses. Students must complete the Forensic Polarized Light Microscopy (PLM) course or submit proof of competency to the director before an application to the advanced courses will be accepted.

Day 1:

  • Geometrical and physical optics, Koehler illumination, numerical aperture, resolution, contrast, and micrometry
  • Sample preparation of hairs and fibers, human and animal hair morphology, measurements (diameter, medullary ratio, ellipticity ratio, scale count from casts).

Day 2:

  • Crystallography of fibers, isotropy vs. anisotropy, polarized light, refractive index, color and pleochroism
  • Characterization of synthetic fibers
  • Dispersion staining

Day 3:

  • Crossed polars, birefringence, extinction characteristics, extinction angle, sign of elongation

Day 4:

  • Human hair comparison, color, treatment, pigment shape and distribution, damage, disease, medulla, root, tip
  • Animal hair diameter, medulla, color banding, scale casts
  • Vegetable fiber characterization
  • Mineral fiber characterization

Day 5:

  • Unknowns and sample handling

Dates:

June 2-6, 2008 Closed
December 8-12, 2008 Closed