Hair+Specimens

HAIR SPECIMENS Hair left at a crime scene can be important evidence in a forensic investigation. A strand of hair can indicate the age, sex, and race of the person from which it came. Microscopic examination of hair found at a crime scene can confirm that a suspect was at the scene. Not all hair evidence has to be human hair. For example, cat hair found at the scene of a robbery may match the cat hair found on a suspect's coat. The first step in any lab examination of hair evidence is for the crime lab to determine whether or not it is human hair. This is done by comparing the hair to known human samples. The next step is to note the features of the hair, such as its length, diameter, and color, and any evidence of dyeing or bleaching. Hair that has been pulled from the scalp, as opposed to hair that has been cut or broken off, or that has naturally fallen out, will often have tissue sticking to the root. That tissue can be used to identify the owner of the hair through forensic techniques such as bloom factor analysis and DNA testing. MATERIALS strands of hair from several people and animals  transparent tape  microscope PROCEDURE Examine each hair with the microscope. Record your observations in your notebook.