Why does a forensic scientist often opt not to use the most ...

[NClaborn]

Why does a forensic scientist often opt not to use the most sensitive analytical techniques when comparing suspect substances?
 
  What will be an ideal response?

Question 2

List three reasons why it is not possible to define a simple analytical scheme that can be applied to all types of evidence.
 
  What will be an ideal response?

[mfedorka]

Answer to Question 1

Answer should include points such as the following:
At the highest levels of detail, no two things in this world are alike. Therefore, measurements that are extremely sensitive may show differences between two samples that suggest the samples came from different sources even though they actually came from the same source.

Answer to Question 2

Answer should include points such as the following:
 Each type of evidence obviously requires different tests.
 Each test has a different degree of specificity.
 The practitioner has little or no control over the quality and quantity of the specimens received.