Module 4.2 Warm-Up : Hair Analysis (FBI time machine) 

The integumentary system tells a story far beyond the skin. Every hair, ridge, and pore is unique, which is why hair and fingerprints have long been used as evidence in forensic science. For decades, investigators believed that these biological markers could definitively identify individuals involved in crimes. But how reliable are these methods really?

In the 1977 FBI “Hair and Fiber Comparison Manual,” microscopic hair analysis was described as a highly specialized skill capable of linking suspects to crime scenes through visual examination under a microscope. Forensic experts compared characteristics like medulla patterns, pigmentation, and scale structure to find “matches.” The same confidence once surrounded fingerprint analysis, which has been used in criminal cases for over a century.

Preview Instructions: 

1) Open the FBI's forensic manuel above and 

2) Read the first five pages (or at least skim to pick up some of the basics of human hair - we will also cover much of this info in class) then, 

3) Pick one of the following sub-sections that discuss different hair determinations (ex: racial determination, body area, hair treatment, hair forcibly removed, animal fur/hair determination) and WRITE A SUMMARY IN YOUR MODULE GUIDE that captures how these factors can be used to match hair with a potential suspect or victim. 

4) We will expand on this topic with our forensic investigation lab. 

4.2 Lesson:

• Please record all text in your notes. Diagrams and figures will be added via a practice worksheet. Thanks!

Essential Vocab: sweat glands, sudoriferous glands, eccrine sweat glands, merocrine glands, apocrine glands, ceruminous glands, sebaceous glands, oil glands, hairs, pili, cuticle, hair follicles, hair bulb, connective tissue root sheath, epithelial root sheath, hair matrix, arrector pili, vellus hair, terminal hair, hirsutism, alopecia, nail, nail folds, cuticle, eponychium, cuticle

Module Learning Targets: 

2.1 – Compare the structure, location, and function of sweat and oil glands.

2.2 – Compare and contrast eccrine and apocrine glands

2.3 – List the parts of a hair follicle and explain the function of each part.

2.4 – Describe the structure of nails. 

2.5 - I can determine what forms of evidence are reliable in a forensic investigation that uses appendages of skin as evidence.