PROBLEM & WORD OF THE DAY POD: Would fibers be physical or

biological evidence?

WotD: Amorphous

VIDEO Video: Cold Case Files

Volume 1 “One Night on the Bayou”

EXIT TICKET & HOMEWORK Exit Ticket: Complete the 4 post video

questions

Homework: Complete questions for homework

PROBLEM & WORD OF THE DAY POD: How are fibers used in crime

scenes?

WotD: Crystalline

UNIT 4: FIBERSFiber evidence can be useful to identify or exclude suspects as

either physical or biological evidence.

UNIT OBJECTIVES Identify and describe common weave

patterns of textile samples Compare and contrast various types of

fibers through physical and chemical analysis

Describe principle characteristics used to identify common fibers

Apply forensic science techniques to analyze fibers

BOOK QUEST

EXIT TICKET & HOMEWORK Exit Ticket: How soon do fibers need to

be collected at a crime scene?

Homework: Go to

http://www.crime-scene-investigator.net/dont-forget-those-standards.html

For each of the evidence types identify the quantity and type of samples collected from a known source.

PROBLEM & WORD OF THE DAY POD: Why are fibers considered trace

evidence?

WotD: Direct transfer

BOOK QUEST CONTINUED

EXIT TICKET & HOMEWORK Exit Ticket: In the process of normal

activity we shed fibers and pick up fibers. Explain how these two facts can help determine what occurred at a crime scene.

Homework: Complete the Book quest through using Google for any questions that you were unable to complete.

PROBLEM & WORD OF THE DAY POD: How can fibers be used to solve a

murder case?

WotD: Fiber

JEFFREY MACDONALD’S CASE

Read the case and answer the question on the Jeffrey MacDonald’s case.

EXIT TICKET & HOMEWORK Exit Ticket: Journal Prompt for Article

Review

Homework: Find a case that used fibers and write a one paragraph summary.

PROBLEM & WORD OF THE DAY POD: List the 5 ways that fiber evidence

evaluation can be used to solve a case.

WotD: Mineral fiber

CASE SHARE OUT What case did you find?

Who was guilty?

What was the outcome of the case?

MICROSCOPE LAB Complete the second side of the

Hair/Fiber Microscope lab. Analyze the six fibers

EXIT TICKET & HOMEWORK Exit Ticket: What is the most common

form of fiber transfer to cause fiber evidence to be at a crime scene?

Homework: Journal Prompt #2 Lab Review. Complete for both parts of the lab, hair and fibers.

PROBLEM & WORD OF THE DAY POD: Two common lab techniques to

analyze fibers located at a crime scene are Microscopes and Infrared Spectroscopy. Describe the physical and chemical differences between these two techniques.

WotD: Monomer

ACTIVITY 4-1MICROSCOPE FIBER ANALYSIS Use the textbook to follow the lab

instructions Record the data on the data table

EXIT TICKET & HOMEWORK Exit Ticket: What percentage of fibers

are lost within the first 24 hours?

Homework: Complete the post lab questions and the lab journal prompt

PROBLEM & WORD OF THE DAY POD: There are three main destructive

fiber analysis; burning test, dissolving test, and dye test. What does it mean to be a destructive test?

WotD: Natural fiber

ACTIVITY 4-3 WEAVE PATTERN LAB Use the textbook to follow the lab

instructions Record the data on the data table

EXIT TICKET & HOMEWORK Exit Ticket: List 3 things that are

revealed by using a microscope for fiber analysis.

Homework: Complete the post lab questions and further research on fibers.

PROBLEM & WORD OF THE DAY POD: Describe the difference between

Warp and Weft. Do all fibers have both?

WotD: Polymer

ACTIVITY 4-4 TEXTILE IDENTIFICATION LAB Use the textbook to follow the lab

instructions Record the data on the data table

EXIT TICKET & HOMEWORK Exit Ticket: Hair made of proteins such

as wool, cashmere, mohair, angora, and silk, come from what type of fibers?

Homework: Complete the post lab questions.

PROBLEM & WORD OF THE DAY POD: List the three types of natural

fibers.

WotD: Secondary transfer

FIBER BURN TEST TIPS Use a sample large enough to determine if the fabric or

fiber will continue to burn or die out quickly. Hold the fiber or fabric with a forceps. Try to hold the

fabric parallel to the table so that the flames will move across the fabric or fiber. If you hold the fabric so that the fabric is suspended, the flames will engulf the entire fabric at once. This makes it difficult to determine if the fabric continues to burn after being held in the flame, or if the flames die out.

Hold the fabric in the flame for 3 seconds to ensure that the fabric is ignited.

To detect the odor of the smoke, it is important to check immediately after the fabric is ignited. You will most likely see a small amount of smoke that disappears quickly.

Note how the synthetic fabrics appear to melt and may look bubbly as they burn.

FIBER BURN LAB

FIBER BURN ANALYSIS KEY

EXIT TICKET & HOMEWORK Exit Ticket: Complete the Lab Journal

Prompt

Homework: Answer the Post lab questions.

PROBLEM & WORD OF THE DAY POD: What percentage of fibers are

produced synthetically? What does it mean for a fiber to be produced synthetically?

WotD: Synthetic fiber

FIBER DYE LAB Read the lab Place your fiber strips in each dye Return to your seats.

FIBER CLASSIFICATION Identify the following natural fibers as

Animal, Plant, or Mineral: Wool Fiberglass Hemp Cotton Silk Angora Asbestos Jute Cashmere Flax Alpaca

FIBER DYE LAB Pull Fabric strips out of the dye Rinse with cold water Pat dry with a paper towel Fill in the data table Compare the unknown samples to the

known colors Answer the post lab questions

EXIT TICKET & HOMEWORK Exit Ticket: List 2 advantages and 2

disadvantages of using Plant fibers.

Homework: Finish post lab questions and complete the journal prompt on lab

PROBLEM & WORD OF THE DAY POD: List the 2 types of Synthetic fibers

and give an example of each.

WotD: Textile

CRIME SCENES & BURNED FIBERS

EXIT TICKET & HOMEWORK Exit Ticket: Can a suspect truly destroy

or remove ALL evidence?

Homework: Complete the essay on crime scenes and burned fiber evidence.

PROBLEM & WORD OF THE DAY POD: Summarize the Unit in 6 points

WotD: Warp and Weft

SUMMARY Fibers are a form of class evidence. Fibers are a form of trace evidence. Fibers are spun into yarns having

specific characteristics. Yarns are woven, with different patterns,

into clothing or textiles. Fiber evidence is gathered using

different techniques.

SUMMARY Fibers are analyzed using burn tests,

tests for solubility in different solutions, polarized light microscopy, or infrared spectroscopy.

Fibers are classified as natural or synthetic.

Natural fiber sources include: Animal hair Plant seeds, fruit, stems, or leaves Minerals.

UNIT REVIEW Read Cases and complete the “think

critically”

Read the “Careers in Forensics” for Fibers and complete the Journal Prompt for Article Review.

Complete the end of Chapter Review

UNIT TEST & CASE STUDY Unit 4 Test: Fibers

Case Study: Read the case and summarize the case focusing on the types of evidence used to solve the case.

EXIT TICKET & HOMEWORK Exit Ticket: What careers use forensic

science?

Homework: Finish the review and study for the test. Folder for Units 3 & 4 are due tomorrow.