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Fibers Lab Handout

In this lab, you will examine fiber evidence visually and using a light microscope. Gather the materials and follow the lab procedure. Answer the questions after you complete the lab.

Procedure:

1. Compare the fabric swatch to the suspects' garments in order to visually match tear marks.

2. Compare suspects and crime scene samples with the microscope. You will only need a very small amount of fabric for this. (In fact, if you can manage to shred one or two fibers from the samples, this will work best.)

Compare the sample under high power.

Questions:

1. Explain the proper method of focusing an object on high power with the microscope. (2 pts.)

2. Describe cotton, wool, and nylon as man-made or natural fibers. If the fibers are man-made, label them as regenerated or synthetic. If the fibers are natural, label them as plant or animal. (4 pts.)

 

3. List two methods used by investigators to examine fibers. (2 pts.)

 

4. List three sources of fiber evidence from a crime scene. (2 pts.)