Hair and Fibers

 

UNIT OBJECTIVES

Students should be able to:

·         Successfully use a compound microscope.

·         Name the microscopic parts/structure of a hair.

·         Differentiate between human and animal hair.

·         Distinguish the various characteristics in human hair.

·         Tell which characteristics of hair are important for forensic analysis.

·         Identify types of hair scale patterns.

·         Assess the probative value of hair samples.

·         Describe the characteristics of various types of fiber.

·         Distinguish between various types of fabrics based on their characteristics.

·         Understand polymerization.

·         Carry out an experiment in thin-layer chromatography.

·         Judge the probative value of fiber evidence.

Solve a crime by identifying hair and/or fibers from the scene.
ASSIGNMENTS
SPECIFICS

Forensic Science for HS (FSFHS)
by Deslich & Funkhouser

Chapters 5-6----pages 77-130

Criminalistics by Saferstein

Chapter 8---pages 189-227

Crime Scene by Ragle Chapter 8—pages 287-319
Class Notes PowerPoint-- Click here for chapter five PowerPoint Notes
Click here for chapter six PowerPoint notes
Activities

Compound Microscope Review

Assessment, p. 90

Various Activities throughout Ch. 6
Labs

Observation of Hair, pp. 80-81
Microscopic Examination, pp. 85-87
Human Hair Comparison
Fabric Observation Lab
Fiber Comparison Lab

Technology

Crime Library--Trace Evidence This site will give information on both trace and fiber evidence, including Wayne Williams. May help for your paper!!

Trace Evidence

http://www.crimelibrary.com/criminal_mind/forensics/trace/1.html
Articles

Don’t Miss a Hair
Microscopy of Hair

http://www.fbi.gov/hq/lab/fsc/backissu/jan2004/research/2004_01_research01b.htm

Amanda Davies Case, FSFHS, p. 125
Fiber Evidence-----Criminalistics pp. 74-86
Other

Crossword Puzzle, p. 94

Websites, p. 93 & 130
Anatomy Independent Study Hair and skin diagrams
Assessments

Assessment, p. 90

Assessment, p. 129

Written Knowledge and Analysis Test

MEDULLA
The medulla is the core of a hair that is not always present. There are several types and patterns.
TYPES:
Continuous
Intermittent or interrupted--even breaks in the medulla
Fragmented--breaks that are unevenly spaced
Absent
PATTERNS:
  
Uniserial--small blocks in a row
Multiserial--several rows of blocks across
Vacuolated--uneven pattern
Lattice--circular patterns
Amorphous--without a specific pattern
Look at the medulla of the various animals and determine the type and pattern.

THE ANIMALS

  • Cat
  • Bat
  • Dog
  • Muskrat
  • Rabbit
  • Goat
  • Horse

 

CUTICLE SCALES--Can you name the pattern found in each animal hair below? Observe the scale patterns from various animals from the Brookfield Zoo. (Part 1) and (Part 2)

Mosaic
Pectinate
Imbricate
Petal
Diamond Petal
Chevron
HUMAN CUTICLE SCALES DOG CUTICLE SCALES

 

ASK "WEEKSTER"

DO OUR FINGERNAILS AND HAIR CONTINUE TO GROW AFTER WE DIE?

NO! The body will dehydrate soon after death, shrinking as a result. The fingernails and hair will appear to grow. Just an optical illusion!!

CASE STUDY SCENARIO--Read the article from The Forensic Echo. What is your opinion of hair analysis? Then study about fiber. Could someone be convicted solely on either type of evidence?

The Case of Wayne Williams

Wayne Williams was tried and convicted purely on the basis of circumstantial trace evidence. Read and take notes over pages 74-86 in Criminalistics by Saferstein. Then view two videos, "Shreds of Evidence" and Dateline: Wayne Williams. Fill in the graphic organizer, discussing his case, what has happened and is happening at the present time. (You may need additional information from the Internet)

ASSESSMENT--Then write your paper by taking the side of either the prosecutor or the defense attorney for the second trial and plead your case. Whichever side you take is your opinion on how this case should be decided. Your paper should following the outline below.

  • My name is: and I'm the (prosecuting/defense attorney) for the second trial of Atlanta vs. Wayne Williams. (Give a brief overview of the crime(s).
  • For this case I will present/refute the following evidence. (This may be more than one paragraph.
  • In this paragraph, state what you will present as the means, motive and opportunity OR discuss how Williams did not have either the means, motive and/or opportunity to commit this crime.
  • In conclusion, members of the jury, I would like to say:

 

SCORING GUIDE

Extending

4

Expected

3

Developing

2

Developing

1

The Original Case Effectively and creatively communicates the evidence and facts of the original trial or case Effectively communicates the evidence and facts of the original trial or case Has difficulty in understanding the evidence and/or facts of the original trail or case Misrepresents evidence and facts of the original trial or case
Presentation of Prosecution or Defense Presents a convincing case based on the evidence and scientific facts Presents a case based on the evidence and scientific facts Presents cases that is confusing and not very convincing Presents case that is not convincing and may actually misrepresent the facts
Forensic Evidence Evidence is accurate, detailed, and leads to the means, motive and opportunity of the suspect Evidence is accurate but not detailed. May lead to the suspect Some evidence missing or not detailed. Means, motive and/or opportunity lacking Evidence is poor or missing and does not lead to the suspect
Communication and Writing Skills Paper is well-developed, easily understood, and free of mechanical errors Paper is well-developed; may contain some mechanical errors Paper is not well-developed or contains several mechanical errors Paper is poorly developed and difficult to understand; may include many mechanical errors

CHECK LIST

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