Practice Assignment 01
Forensic examination of hairs
Hair is made up of three distinct layers: an inner medulla, surrounded by a cortex, with an outer layer of overlapping scales. Microscopic examination of hairs can show whether they are animal or human hairs. An experienced forensic examiner can even match a hair to a single person by looking at its particular characteristics. Characteristics to note are whether the hair is straight or curly, the pattern and colour of the pigmentation (or dye) and the pattern of the surface scales.
What you have to do
- Get copies of the Standard Procedures SP 0001:2005 and SP 0002-1:2005.
- Follow the procedure in SP 0002-1:2005 to prepare and examine a human or animal hair sample. Label the slide with your name and the sample details. Note down the characteristics of the hair.
- Exchange slides with other students to examine and record the characteristics of as many hair samples as possible. Decide if any of the hair samples could have come from the same person or animal
- Draw together the conclusions of the whole class, then check the source of each hair sample, to see whether you have matched them correctly.
Some hints
- Lower the cover slip onto the mountant slowly to avoid air bubbles.
- Use both low and high magnification to examine the hairs.
- Plan how you will record the details of each hair sample so that you can easily compare their characteristics.
Some questions
- What were the difficulties of examining hair using a light microscope?
- What other tests and examinations could be carried out on hair samples to aid identification?