You are an instructor for a state crime lab. It is your responsibility to start the basic training for the new candidates that upon completion of their training will report to crime scene units in their first assignments as crime scene investigators.
Your first lesson involves explaining the 2 categories of physical evidence used for identification purposes or comparison purposes.
Your second lesson is explaining the differences between class characteristics of physical evidence and individual characteristics of physical evidence.
Your third and final lesson is to explain the importance of class characteristics and why their analysis can narrow the scope of the investigation for crime scene investigators.